Johns Hopkins Health Alerts - Nutrition and Weight Control

Testing Your Vitamin D Levels

Wed, 04 Nov 2009 06:00:00 CST

This question comes from our popular Health After 50 newsletter. A reader asks: Should I have my vitamin D levels tested? Johns Hopkins professor, Dr. Michele Bellantoni answers.

Yes, if you're over 65. Vitamin D deficiency increases your chance of fractures, muscle loss, and bone pain, explains geriatrician Michele Bellantoni, M.D., Medical Director of Hopkins Bayview Care Center and Health After 50 Board Member.

Two blood tests are used to measure vitamin D levels. Most people only need the 25-hydroxy vitamin D test, says Dr. Bellantoni . The other test, referred to as the 1,25-dihydroxy vitamin D test, is used for people with high calcium levels, kidney disease, or certain cancers. Both tests cost around $50 and are covered by Medicare.

If your levels are low, consider taking a vitamin D supplement. Aim to get 800 units of the vitamin daily, says Dr. Bellantoni. Or, if you have no history of skin cancer, you can head outdoors to catch a little sun instead of taking a supplement. "Get out and walk for a few minutes," says Dr. Bellantoni. "It's good for your heart, it's good for your bones, and it's good for your vitamin D." Ten minutes of sunshine a day without any protection (including cosmetics or moisturizers with sunscreen) is probably enough to safely boost vitamin D. Sitting by a window won't work, because the glass blocks the sun's rays, says Dr. Bellantoni.

There are no established guidelines for how often a person should have his or her vitamin D levels checked. Dr. Bellantoni recommends rechecking levels if there has been a considerable reduction in sun exposure or if you have changed your daily intake of supplements over a two-month period.

Phytochemicals: Essential to Good Health

Wed, 23 Sep 2009 06:00:00 CDT

Fruits, vegetables, and other plant foods are packed with healthy compounds known as phytochemicals, in addition to vitamins, minerals, and fiber. From anthocyanins (the red pigment in strawberries and cherries) to allylic sulfides (responsible for the pungent flavor of garlic and onions), these phytochemicals may be responsible for some of the disease-preventing effects of fruits and vegetables.

Phytochemicals have no nutritive value -- that is, they are not vitamins or minerals -- but they may have positive effects on the body over the long term. Possible beneficial effects include inhibiting tumor formation, preventing blood clots, blocking the cancer-promoting effect of certain hormones, and lowering cholesterol levels.

Follow these tips to increase the phytochemicals in your diet.

Consume a plant-based diet. Try to eat nine servings of fruits and vegetables a day (including 3 cups of legumes a week) and six servings of grain products each day. Vary the choices to get a wide range of phytochemicals, focusing on dark green vegetables, red and orange fruits and vegetables, and whole grains.

Season foods with herbs and spices. These seasonings also contain phytochemicals. Try using garlic, shallots, ginger, basil, oregano, parsley, rosemary, cumin, curry powder, cayenne pepper, red chili pepper, and cinnamon, to name a few.

Incorporate soy products into your diet. Tofu, soy protein, soymilk, soy flour, soy butter, and edamame (edible green soybeans) can all be included in your diet as long as you have not been advised to avoid them. Tofu and other soy products are mild tasting and pick up the flavor of the foods they are cooked with. Tofu can be stir-fried with vegetables or added to soups. Soy flour can be substituted for up to one quarter of the flour in baking recipes, and soy butter can be spread on bread in place of peanut butter.

Oats Stand the Test of Time

Wed, 02 Sep 2009 06:00:00 CDT

Various studies have looked at whether oats truly benefit the cardiovascular system. Now a review published in the American Journal of Lifestyle Medicine (Volume 2, page 51) says the grain has lived up to the claims.

Oats were a nutritional darling during the 1990s, after the Food and Drug Administration announced oats may reduce the risk of developing heart disease when combined with a diet low in saturated fat and cholesterol.

By assessing 10 years of studies, authors of the recent report found that almost all of the research on oats' effects reached the same conclusion: Eating oats may reduce blood concentrations of total cholesterol and low-density lipoprotein (LDL) cholesterol without adverse affects on levels of high-density lipoprotein (HDL) cholesterol or triglycerides.

The review also reported that diets rich in whole grains such as oats (three or more servings per day) may help reduce the risk of type 2 diabetes, cardiovascular disease, and obesity. Research suggests that the soluble fiber in oats increases bile acid excretion, which in turn reduces cholesterol levels in the blood. Oats have the highest proportion of soluble fiber of any grain.

Bottom line: Eat more oats. To add oats to your diet, fix yourself a bowl of oatmeal for breakfast (preferably with no added sugar) or opt for products rich with the healthy grain. Just remember that many foods have "oat" in their names but contain only small amounts; look for whole oats, oatmeal, or oat bran as the first ingredient.

6 Reasons To Love Beans

Wed, 12 Aug 2009 06:00:00 CDT

If you aren't including plenty of dry beans and other legumes in your diet, you're missing out on some of the best nutritional multitaskers around. Beans are an excellent source of several important nutrients, and studies suggest that they reduce the risk of heart disease, colorectal cancer, and, possibly, even diabetes. What's more, beans are savory, easy to prepare, inexpensive, and come in many varieties.

With so many good reasons to eat beans, it doesn't add up that Americans eat only about one cup of beans a week, when the U.S. Department of Agriculture (USDA) Dietary Guidelines for Americans recommends a minimum of three cups.

Here are six reasons why we should all eat more beans:

Beans are full of vitamins and minerals. Beans are a good source of minerals, like calcium, copper, zinc, iron, and potassium, and B vitamins, such as folic acid.

Beans are high in fiber. Beans contain impressive levels of dietary fiber: 12 to 15 g in a one-cup serving, which translates to half or more of the daily recommended fiber intake of 21 to 30 g for older individuals. They are a rich source of both soluble and insoluble fiber. The insoluble fiber in beans absorbs liquid in the colon and helps soften stool, which protects against constipation.

Beans are packed with protein. One cup of cooked beans provides as much as 16 g of protein, about a quarter to a third of the amount you need in a day.

Beans stabilize your blood sugar. Soluble fiber in beans slows the passage of glucose from food into your bloodstream. Because of this, your body has to produce less insulin; high levels of insulin are a precursor to diabetes.

Beans are heart-healthy. Scientific evidence that beans promote heart health continues to grow. In a study conducted by the USDA Agricultural Research, researchers found that consuming as little as a 1⁄2 cup of beans a day helped lower total and low-density lipoprotein (LDL) cholesterol levels in healthy people as well as in those with an increased risk of heart disease.

Beans may reduce colon cancer risk. Increasing bean consumption by a significant amount may protect against the recurrence of precancerous polyps that can lead to colorectal cancer, the second leading cause of cancer death in the United States.

7 Keys to Cutting Calories

Wed, 22 Jul 2009 06:00:00 CDT

Permanent alterations in your lifelong attitudes toward diet and exercise are the keys to successful weight management. Here are seven no-nonesense strategies to help you eat more moderately, yet feel satisfied.

Clean your plate! It’s a mantra in America, and a contributor to the ever-increasing weight problem. Unfortunately, our plates have gotten bigger! A major part of the weight problem is portion sizes, which have grown substantially over the past four decades: A Coke has increased from 6.5 to 20 fl oz. or more, a bagel from 2–3 to 4–6 oz., and a chocolate bar from 1 to 1.5–8 oz.

Another part of the weight problem is satiety; we often just don’t feel full when we control our calories. According to researcher Barbara Rolls, Ph.D., a nutritionist at Pennsylvania State University and co-author of The Volumetrics Weight-Control Plan, “Satiety is the missing ingredient in weight management. Cut calories simply by eating less and you’ll feel hungry and deprived.”

Here are some weight control strategies for controlling your portion sizes while still eating enough to feel satisfied.

Weight Control Tip 1 -- Know Your Portion Sizes. There’s a difference between serving size and portion size. A serving is a standard amount of food containing a set amount of calories; a portion is what you actually put on your plate. So a portion could be a lot more than a single serving -- and therefore contain a lot more calories than you might expect.

Weight Control Tip 2 -- Check Food Labels Closely. You can’t assume a package contains a single serving just because the label lists calorie and nutrient information for one serving. Look for the number of servings per package (it’s listed directly under the serving size) to determine the true calorie count.

Weight Control Tip 3 -- Divide and Conquer. Research shows that the bigger the plate, bag, or container of food, the bigger your eyes -- and it appears that the eyes have more control over how much you eat than your stomach.

Weight Control Tip 4 -- Go High Fiber, High Water. Eat foods that have a high water and/or high fiber content and are low in fat. This is the key concept behind Dr. Rolls’ Volumetrics approach. Soups, salads, stews, casseroles, fruits, vegetables, low-fat milk, cooked grains, and beans are all good choices. These “wet” foods have a low energy density -- meaning the water and fiber they contain will fill you up with a small amount of calories -- as opposed to “dry” foods like cookies, cereal, and crackers, which have a high energy density.

Weight Control Tip 5 -- Start Meals with Soup or Salad. Dr. Rolls has found that people tend to eat less when they precede a meal with a low calorie soup or salad (with fat-free dressing).

Weight Control Tip 6 -- Eat a Variety of Foods. Dr. Rolls’ research reveals that even when you’re full from one type of food, say a salty snack, you can still make room for another type of food, say a sweet dessert. By eating a small amount of different-tasting foods, you can create a sense of fullness without a lot of calories.

Weight Control Tip 7 -- Emphasize What You Can Eat, Not What You Can’t. Positive thinking extends to weight management, too: After all, diets often fail because we feel deprived. By focusing on what you can eat, you’ll feel better about your weight loss program than if you focus on all you’re missing.

Can You Be Fat But Fit?

Wed, 10 Jun 2009 06:00:00 CDT

Everyone knows that it’s unhealthy to be very overweight. But what if you are obese but still relatively physically fit? Does being fit cancel out the health risks of being obese, or at least some of them? In other words, is it possible that being obese isn’t the real problem, but rather being unfit?

Although some obese people, as well as some researchers, make this claim, there are no easy answers to these questions. First, it’s hard to define the terms. Overweight and obesity are usually defined in terms of body mass index (BMI), which is an imperfect gauge of body fat. Physical fitness varies from person to person and by age. Fitness means different things to a dancer, lumberjack, mailman, or weight lifter. But for researchers, fitness is generally defined as cardiovascular (aerobic) fitness -- the ability to carry on a vigorous activity such as running or brisk walking for an extended period.

Obese people face many increased risks -- for diabetes, high blood pressure, and high cholesterol, all of which boost the risk for cardiovascular disease. Obese people also face an elevated risk for many types of cancer and several other diseases. Thus, obese people, almost across the board, have significantly lower life expectancy than leaner people.

However, there is some evidence that for obese people who are fit, the risks are less dramatic. For instance, in a study looking at more than 5,000 men and women (age 30 to 75), researchers at the University of North Carolina reported that being obese and being unfit both increase the risk for premature death, while fitness reverses some, but not all, of the increased risk associated with excess body fat.

Some of the best-known research on this subject comes from the Cooper Institute for Aerobics Research in Dallas. Its studies have reported that obese men who become fit lower their risks. Men who are obese and fit actually face lower risks than those who are lean but unfit. Therefore, when it comes to cardiovascular mortality, fitness may be more important than weight, at least for men.

Being sedentary and unfit are major contributors to being overweight and obese. And when overweight people start to exercise more, they usually lose weight (especially if they control their calorie intake) and lower their blood pressure and cholesterol levels. That’s why, in these studies, relatively few obese people are very fit. Most obese people don’t (or can’t) exercise much, and those who truly become fit tend to lose weight. Just because there are some fit, healthy obese people, you shouldn’t conclude that it’s healthy for most people to stay obese.

Trans Fat-Free Tips

Wed, 20 May 2009 06:00:00 CDT

The American Heart Association recommends that you keep your trans-fat intake to less than 1% of your total calories. If you consume 2,000 calories a day, that's no more than 2 g of trans fat daily. On average, Americans get 2-3% of their total calories from trans fat.

Health officials have grown increasingly concerned about the potential dangers of trans fat, as research continues to show that a high trans-fat diet causes "bad" low-density lipoprotein (LDL) cholesterol levels to rise and "good" high-density lipoprotein (HDL) cholesterol levels to fall. There's also evidence that in a small percentage of adults trans fat may promote blood clot formation and inflammation and increase blood levels of triglycerides, lipoprotein(a), and small, dense LDL particles. All of these changes may increase your risk of a heart attack.

Getting rid of trans fat in your diet is not the only dietary route to a healthy heart. Don't forget that choosing a balanced diet that emphasizes fruits, vegetables, and whole grains and that is low not only in trans fat but also in saturated fat, cholesterol, and sodium is important, too.

In addition, remember that removing trans fat does not magically transform a trans fat-free food into a healthy food choice, especially if it is still high in both fat and calories. In fact, the trans fat-free version typically has the same amount of fat and calories as the trans fat-laden original.

Try some of these strategies for minimizing the amount of trans fat in your diet.

At Home:

Limit your intake of foods that commonly contain high amounts of trans fat, such as crackers, cookies, doughnuts, and frozen foods like pizza, french fries, chicken nuggets, and fish sticks.

Read nutrition labels and choose foods that are low in trans fat -- preferably less than 1 g per serving.

Don't forget to check the ingredient list. Even foods labeled 0 g trans fat can contain a small amount (up to 0.5 g per serving). Finding "partially hydrogenated" oil on the ingredient list is a tip-off to the presence of trans fat, regardless of what the label says.

Also be on the lookout for palm, palm kernel, cottonseed, and coconut oils as well as "fully hydrogenated" oils in the ingredient list. These unhealthy saturated fats are often used in place of trans fat.

When Eating Out:

Request nutrition information. A growing number of restaurants have this information but often don't advertise or prominently display it.

Check the Web first. Many chain and fast-food restaurants provide nutritional information on their websites.

Ask your server for information. What type of oil do you use for frying? What oil do you use in your salad dressing? Do you use vegetable shortening in your desserts and other baked goods?

Skip the fried foods, which are likely to be loaded with unhealthy trans and saturated fats. Baked, grilled, steamed, and broiled foods are smarter, lower-fat choices.

Eat only half your dish to reduce your trans fat intake. Portion sizes are so large at most restaurants that they can easily serve two.

How To Eat More Veggies

Wed, 08 Apr 2009 06:00:00 CDT

The latest food pyramid recommends that you eat 2-4 cups of vegetables a day (the exact amount depends on your age, gender, and activity level). But that's not always an easy task. Here, then, are some ideas from the experts on how to get your vegetables -- and enjoy them, too.

Sneaking In Your Vegetables

Pile vegetables onto your sandwiches. Don't stop at lettuce and tomato. You can also add cucumbers, shredded carrots, or peppers, to name a few.

Hide the vegetables. If you're not a vegetable fan, try adding vegetables to other dishes to hide their flavor. Purée cooked vegetables such as potatoes and add them to stews, soups, and gravies to make them thicker. Add shredded carrots or zucchini to meatloaf, casseroles, muffins, and breads, and chopped broccoli, mushrooms, or green beans to tomato sauce. Use spinach in lasagna instead of meat. Top pizza with mushrooms, peppers, and other vegetables, and load egg dishes such as omelettes and frittatas with sautéed vegetables.

Mix up your cooking routine.

Try stir-frying or sautéing vegetables, grilling them on skewers or in tin foil, or roasting, baking, or lightly steaming them (to retain their crunch and nutritional wallop).

Or try stuffing your vegetable. Load a baked potato with some broccoli and low-fat cheese or some tomato sauce, chopped spinach, and part-skim mozzarella; then broil, bake, or microwave until it bubbles. The same goes for a red or green pepper -- fill with lentils or rice and beans and cook.

Add some flavor. Healthy fats such as olive or peanut oil lightly drizzled over vegetables or in a stir-fry can make them much tastier, as can herbs and spices like basil, tarragon, and oregano.

Also consider sauces and dips for your vegetables; just make sure they're low in saturated fat. Good options include salsa, hummus, and low- fat yogurt dips.

Make vegetables the main dish. Plan your meal around a salad, soup, or vegetable stir fry. Add small servings of other foods -- lean meat or poultry or low-fat dairy products -- as side dishes.

10 Reasons Why Americans Are Overweight

Wed, 29 Apr 2009 06:00:00 CDT

Weight control is far more complex than simply balancing calories consumed with energy expended. Here are 10 top (alternative) reasons why Americans are overweight – and some may surprise you.

Rates of obesity are higher than ever in the United States. According to the Centers for Disease Control, more than six in 10 American adults are overweight or obese -- and most adults are about 25 lbs heavier than people were in the 1960s. To make matters worse, more than half of all overweight people actually think they’re at a healthy weight, according to a recent Associated Press poll.

In theory, weight control is a simple matter of balancing energy intake (the calories supplied by food) with energy output (the calories expended by physical activity, the digestion of food, and the functioning of your body). To lose weight, you need to expend more energy than you take in. In practice, however, the task is not that simple. While the basic principle of energy balance remains true, several mechanisms -- genetic, metabolic, and environmental -- can affect how much you eat and how your body uses and stores energy.

A revealing study published in the International Journal of Obesity (online edition, June 27, 2006) highlighted 10 reasons why Americans are fat. The study explained that too much food and a lack of exercise are not the only factors contributing to obesity. They identified 10 other possibilities:

Weight gain factor 1 -- Less sleep. We’ve gone from an average of nine to seven hours of sleep a night; sleep deprivation is linked to a more robust appetite.

Weight gain factor 2 -- Pesticides and other chemicals in foods. These substances can change hormonal activity, which can boost body fat.

Weight gain factor 3 -- Air conditioning and heating. We don’t sweat and shiver as much as our ancestors, so we don’t burn as many calories.

Weight gain factor 4 -- Fewer smokers. Nicotine is an appetite suppressant.

Weight gain factor 5 -- Greater use of medications, such as antidepressants and diabetes drugs, which have weight gain as a potential side effect.

Weight gain factor 6 --Population changes. There are now more older people as well as more Hispanics in the United States, and these groups have higher rates of obesity.

Weight gain factor 7 -- Older birth mothers, whose children are more prone to excess weight gain than the offspring of younger mothers.

Weight gain factor 8 -- Genetics. Obese moms may pass the trait onto their children in utero.

Weight gain factor 9 -- Higher body weight = greater fertility. Heavy people produce more offspring than thinner people.

Weight gain factor 10 -- Assortative mating. Heavy people tend to mate with each other and produce heavy children.

How to Avoid Vitamin D Deficiency

Wed, 25 Feb 2009 06:00:00 CST

The latest research suggests that vitamin D may play a more important role in health than had been suspected. But many of us do not get enough vitamin D. In this article from our Health After 50 newsletter, Johns Hopkins experts explain why you need vitamin D – and how to get it.

Your need for some nutrients, especially those affecting your bones, increases as you get older. One of these nutrients is vitamin D -- the only vitamin your own body can manufacture.

Sunlight stimulates the production of vitamin D in the skin -- a mixed blessing, since the ultraviolet rays of the sun can also damage skin. But you also need to get vitamin D from food and supplements. From age 50 to 70, the recommended intake of vitamin D is 400 IU per day -- the amount in 4 cups of fortified milk. After age 70, you need 600 IU per day. The new U.S. dietary guidelines endorse much higher amounts -- 800 to 1,000 IU daily. Studies show that vitamin D deficiency is common, especially in people over 60.

Why do you need vitamin D? It is essential for bones and teeth. Without vitamin D, your ability to absorb calcium is reduced, and calcium is essential for strong bones and teeth. Vitamin D is also vital for muscle strength, and a deficiency may lead to falls and fractures. Thus, lack of vitamin D causes fractures in two ways: Weakened muscles lead to falls that result in fractures of thin bones.

The latest research suggests that vitamin D may play a more important role in health than had been suspected. Healthy bones may not be the only function of vitamin D. Shortages may also be linked to multiple sclerosis, diabetes, and rheumatoid arthritis, as well as to breast and prostate cancers. All these disorders are more common in northern regions where people get less sun -- and lower vitamin D levels may be part of the explanation.

Getting your vitamin D -- Adults often drink too little milk -- a real dietary loss because both soy and cow's milk are fortified with vitamin D. (Not all milk products are good sources -- yogurt and cottage cheese are NOT made from fortified milk.)

Fish is also a good source of vitamin D; eggs have a small amount of vitamin D. But you should not eat fish every day, and those following heart-healthy diets have to limit eggs.

The typical multivitamin pill has 400 IU of vitamin D. Some calcium supplements also contain vitamin D, so you might buy one of these if you are taking calcium. But keep in mind that vitamin D can be harmful in dosages above 2000 IU daily. Avoid cod liver oil. It is very rich in vitamin D -- you could overdose, particularly if you are taking supplements. Cod liver oil also contains high levels of vitamin A, which can weaken bones.

How Much Exercise Is Enough?

Wed, 04 Feb 2009 06:00:00 CST

Do you get enough exercise? How much exercise is enough? These questions are answered in new guidelines from The American Heart Association and the American College of Sports Medicine. Here's what they recommend.

A low level of physical activity is one of the most important factors in the high and rising rate of obesity in the United States. Becoming physically active can have a tremendous impact on your total daily energy expenditure.

For example, a sedentary person burns just a few hundred calories above his or her resting metabolic rate while going about daily activities (performing household chores or walking to the mailbox, for example), whereas someone who exercises regularly at a moderate pace doing light gardening or yard work, walking, or dancing can burn an additional 150 calories per half hour -- and build muscle mass. Exercises that build strength also raise the resting metabolic rate because muscle requires more energy for maintenance.

With this in mind, we note the new exercise guidelines released by The American Heart Association and the American College of Sports Medicine and reported in the journal Circulation (Volume 116, page 1094):

Adults ages 65 and older should engage in at least 30 minutes of moderate-intensity aerobic activity five days a week or at least 20 minutes of vigorous-intensity aerobic activity three days a week. A mix of the two intensities (for instance, brisk walking for 30 minutes and jogging for 20 minutes twice a week each) as well as short bursts of exercise for 10 minutes each will suffice. These exercise recommendations are the same as those for ages 18–65, except what is considered aerobic activity for the older group may be less intense depending on a person's fitness level.

Older people are also recommended to perform both strength-training exercises and flexibility exercises at least twice a week as well as balance exercises. The exercise guidelines -- which update recommendations issued in 1995 -- highlight that the more exercise one engages in, the better the health-protective benefits. Previously, light-intensity activities of daily living, like casual walking and grocery shopping, could be counted toward one's daily exercise total; now, however, it's believed that they aren't performed for a long enough period of time (if less than ten minutes) or at enough intensity to offer the needed benefit.

More Evidence Against Trans Fats

Wed, 14 Jan 2009 06:00:00 CST

Trans fats are formed when food manufacturers add hydrogen to vegetable oil to make it more solid. Americans get much of their trans fat from the partially hydrogenated oils found in cookies, crackers, pastries, and fried foods. Among dietary fats, trans fats are uniquely hard on the heart, as they raise "bad" LDL cholesterol while lowering "good" HDL cholesterol.

By now you've probably heard that trans fat is one of the unhealthiest fats in the American diet. That's because trans fat not only raises low-density lipoprotein (LDL, or "bad") cholesterol but trans fat also lowers the "good" high density lipoprotein (HDL) cholesterol. In fact, trans fat is so harmful to your health that the Institute of Medicine says there is no safe level of intake and recommends consuming as little trans fat as possible. The American Heart Association has put a number on "as little as possible," advising Americans to keep their trans fat intake below 1% of total calories. On a 1,800-calorie-a-day diet, that's less than 2 g of trans fat a day.

To make it easier for you to reduce trans fat intake (it's virtually impossible to consume no trans fat at all), the U.S. Food and Drug Administration now requires food manufacturers to list the amount of trans fat on the Nutrition Facts panel. (The amount is listed beneath the entry for saturated fat.)

Recently a large study reported in the journal Circulation (Volume 115, page 1858) confirmed the dangers of consuming trans fats.

Among nearly 33,000 U.S. women in the Nurses Health Study, those with the highest levels of trans fatty acids in their circulating red blood cells were three times more likely to develop coronary heart disease over the next six years than those with the lowest levels.

The link remained when age, overall diet, and other lifestyle factors were weighed -- suggesting that the trans fats themselves contributed to coronary heart disease development.

This study bolsters the case against trans fats. Instead of simply relying on reported diet habits, it measured trans fat levels in participants' blood -- a more accurate indicator of the intake of trans fat, which the body cannot synthesize.

The bottom line on trans fats: Instead of processed snack foods, reach for whole foods, like fruits, vegetables, and whole grains. And when it comes to fat, choose the healthy forms found in fish, nuts, and olive oil.

Losing Weight the Smart Way

Wed, 24 Dec 2008 06:00:00 CST

Are you overweight or obese? In this Health Alert Johns Hopkins offers practical advice to help you lose weight easily and safely.

The best way to lose weight and to keep it off is to make changes in both your diet and level of physical activity. To lose about one pound per week -- a gradual and safe rate of weight loss -- you must cut out about 500 calories per day.

You could just eat 500 fewer calories, but combining exercise with diet results in greater losses of body weight and fat than dieting alone. By adding a half hour or more of moderate exercise each day (enough to burn 250 calories), you can reduce your calorie restriction to a more manageable 250 calories daily.

Cutting calories. Instead of embarking on a fad diet to lose weight, simply make sensible food choices: Replace dietary fat with complex carbohydrates (for example, fruits, vegetables, and whole grains), which automatically lowers your calorie intake but allows you to eat a satisfying volume of food.

In addition, eat lean instead of fatty cuts of meat, choose reduced-fat or reduced-calorie products when possible, opt for non-calorie beverages such as water, diet soda, or seltzer, and fill up on less energy-dense foods like fruits, vegetables, salads, and soups. Also, learn to read nutrition labels and stick to the portion sizes on the label.

Adding exercise. When planning an exercise routine, choose activities that are convenient and enjoyable. The following are some popular exercises and the calories burned after 30 minutes of activity:

Swimming: 301 calories

Walking (brisk): 149 calories

Tennis (singles): 275 calories

Yoga: 180 calories

Golf: 120 calories

Dancing: 185 calories

Gradually build up to 60-90 minutes of exercise daily. Don't be discouraged, though; you don't need to get all your exercise at one time. Breaking it up over the course of the day is just as effective.

Are You Overweight or Obese? The easiest way to find out is to calculate your body mass index (BMI), a measure of your weight in relation to your height.

Multiply your weight in pounds by 703.

Multiply your height in inches by itself.

Divide the result in step 1 by the result in step 2.

If your BMI is between 25 and 29.9, you are overweight. You're considered obese if your BMI is 30 or more.

How To Maintain Your Weight Loss

Wed, 22 Oct 2008 06:00:00 CDT

Exercise is a valuable element of a weight loss program. Although exercise alone leads to only modest weight loss, and at a slower rate than calorie restriction, combining exercise with diet results in greater losses of body weight and fat than dieting alone. But what about your exercise program once you've achieved your weight goal? Johns Hopkins reviews that data to answer this important question.

Exercise is especially important for weight loss maintenance, which is harder to sustain than losing weight in the first place. And adding exercise to calorie restriction makes the dietary changes easier because they need not be as drastic. It is easy to see why this is so. To lose one pound per week requires a deficit of about 500 calories a day. By adding a half hour of moderate to vigorous exercise each day (enough to burn 250 calories), you can reduce the calorie restriction to a more manageable 250 calories daily.

But the good news is that high levels of exercise are not need to maintain weight loss – this according to a study published in the journal Obesity (Volume 15, page 1226). Exercising at a moderate intensity for an hour or more on most days of the week is generally recommended to maintain weight loss. However, a study from the University of Alabama at Birmingham suggests that a high level of physical activity isn't the only route to successful weight maintenance.

Eighty-nine participants in the university's Eat Right weight-loss program were evaluated a year after they completed the program. Eighty percent of the participants had maintained their weight loss (regained less than 5% of their ending body weight). The researchers found that the maintainers consumed 384 fewer calories per day on average than the participants who regained their weight. They also tended to eat more low-energy density foods, such as low-calorie but filling fruits and vegetables, than the regainers.

However, no significant differences were noted in the amount of exercise engaged in by the maintainers vs. the regainers -- although there was a suggestion that subjects who exercised more regained less weight than those who exercised just a little or not at all.

The bottom line: While exercise is recommended to maintain a weight loss, you may be able to get away with more modest (and doable) amounts than typically advised if you eat a low-calorie diet.

Small Changes Equal Big Impact on Your Cholesterol

Wed, 12 Nov 2008 06:00:00 CST

Exercise and adopt a healthy diet. This age-old advice still holds true for those of us who need to improve our cholesterol profiles. In this Health Alert, Johns Hopkins nutritionists provide practical advice to help you achieve your cholesterol goals – even if you also take statin medication.

You hear it all the time: Watch your cholesterol. Elevated cholesterol levels, along with high blood pressure, smoking, and excess weight, increase your risk of coronary heart disease. But what exactly does watching your cholesterol entail?

It means lowering low-density lipoprotein (LDL) cholesterol, the type that narrows arteries, while striving to boost high-density lipoprotein (HDL) cholesterol ("good" cholesterol), which helps remove LDL cholesterol deposited in artery walls.

Total cholesterol levels should be less than 200 mg/dL, with LDL cholesterol as low as 70 mg/dL if you have coronary heart disease and as high as 160 mg/dL if you have no risk factors for coronary heart disease. Ideally, HDL cholesterol should be above 60 mg/dL or at least above 40 mg/dL in men and 50 mg/dL in women.

But to take the next step by making lifestyle changes to get your cholesterol levels in the right range, you need a game plan. That applies whether or not you've been prescribed a cholesterol-lowering medication.

Small Changes, Big Impact -- Try making gradual heart-healthy changes in your current diet. You're more likely to stick with your new eating plan if you start slowly:

Add a vegetable serving to your lunch or dinner.

Substitute a piece of fruit for cookies, cake, or ice cream as your dessert or snack.

Drink low-fat or skim milk at lunch instead of soda.

Cut back on meat portions by a half or a third at each meal. (Shoot to eat 3 oz, the size of a deck of cards.) Select only lean cuts; trim away fat; broil, roast, or boil (don't fry!); and remove skin from poultry.

Eat one or two meatless meals a week.

Choose whole-grain foods. (Look for the word "whole" instead of "unbleached" or "enriched" as part of the first ingredient listed in a product.)

In addition to dietary changes, experts recommend burning 1,500 calories a week with exercise to impact levels of cholesterol and especially triglycerides, which breaks down to about 20–30 minutes of daily moderate-intensity activity like walking, swimming, or cycling.

While lifestyle is important, oftentimes using a medication, like a statin, is the most effective way to reduce LDL cholesterol. Still, dietary changes can help ward off the need for drugs or help your medication work more effectively.

Food Safety Advice

Wed, 10 Sep 2008 06:00:00 CDT

Johns Hopkins nutritionist Lora Brown Wilder explains how to keep bacteria from poultry or meat out of your kitchen.

Q. I recently heard that you should not wash poultry or meat before cooking it. Why is this?

A. It’s because: (a) cooking the meat or poultry thoroughly will kill any bacteria, and (b) rinsing meat and poultry can splash bacteria onto dishware, utensils, and other foods.

Always cook meats and poultry at recommended temperatures to kill bacteria and use a meat thermometer to ensure that the meat is cooked all the way through. The U.S. Department of Agriculture (USDA) recommends a safe internal cooking temperature of 160 degrees F for ground beef, pork, veal, and lamb, and 145 degrees F for steak and roasts. Chicken breasts and whole birds should be cooked to 165 degrees F.

Follow these other tips for safe meat and poultry preparation:

Store raw meat, poultry, and seafood at the bottom of the refrigerator so their juices don’t drip onto other foods.

Defrost and marinate meat, poultry, and seafood in the refrigerator -- never on the kitchen counter.

Use different cutting boards and plates for raw meat, poultry, and seafood vs. produce, ready-to-eat, and cooked foods.

Wash all utensils and cutting boards in hot, soapy water after you prepare each food item.

Refrigerate leftovers promptly after eating.

Wash your hands frequently before, during, and after cooking.

Which is Healthier: Butter or Margarine?

Wed, 30 Jul 2008 06:00:00 CDT

In this "Ask the Doctor" column from the Hypertension and Stroke White Paper, a reader asks, "Which is healthier: butter or margarine?" The answer may surprise you.

A. Trans fat-free tub and liquid margarines are healthier choices than butter because they contain the least “bad” fats.

The trouble with butter is that it has both saturated fat (7 g per tbsp) and cholesterol (33 mg per tbsp), which can raise your total and LDL cholesterol levels and clog your arteries. Regular margarine isn’t necessarily better: The more solid a margarine is, the more trans fat it contains -- most stick margarines have a whopping 3 g of trans fat per tbsp (as well as 2 g of saturated fat per tbsp).

Since there is no established safe level of trans fat consumption, it’s best to eat as little as possible. Look for margarines that list liquid vegetable oil -- not partially hydrogenated vegetable oil -- as their first ingredient. Some have less than 0.5 g of trans fat per serving and are considered trans-fat free.

Just be sure to control your calories when using these products, since fats are the most caloric foods we eat: On a diet containing 2,000 calories a day, the Dietary Guidelines recommend no more than 6 tsp of oils and fats a day.

Finally, when cooking, use oils that are high in monounsaturated fat -- like olive or canola oil -- instead of butter or margarine. Monounsaturated fats are considered healthy when consumed in moderation because they reduce harmful LDL cholesterol levels and raise beneficial HDL cholesterol levels.

Over-The-Counter Alli For Weight Loss

Wed, 01 Oct 2008 06:00:00 CDT

Should you take Alli to lose weight? Johns Hopkins weighs in on this new weight loss drug.

The first FDA-approved nonprescription weight-loss drug is now on the U.S. market. Called Alli, the drug is a low-dose version of the prescription medication orlistat (Xenical).

Clinical trials show that people who take the drug Alli in combination with diet and exercise typically lose 5–10 lbs over a six-month period -- slightly more weight than they would lose with diet and exercise alone.

Alli blocks absorption of dietary fat in the intestine, allowing one quarter of that fat to pass through the system undigested into the feces, thereby reducing calorie intake. This undigested fat can produce unpleasant side effects, such as diarrhea, gas, oily stools, and involuntary discharge of stool. It also results in the loss of fat-soluble vitamins, such as vitamins A, D, and E, in the feces.

Even though the drug is available without a prescription, it is not for everyone. People who are not overweight, those who have had an organ transplant, and those who have problems absorbing food should not use Alli. In addition, people taking warfarin (Coumadin) or being treated for diabetes or thyroid disease should consult their doctor before using this over-the-counter weight-loss drug. Alli is taken with fat-containing meals up to three times a day. A pack of 90 capsules costs approximately $50.

Fitting Exercise into Your Life

Wed, 09 Jul 2008 06:00:00 CDT

Being physically active has so many health benefits. So if you are thinking you can't possible fit 30 minutes or more of exercise into your daily routine, these tips from Johns Hopkins can help.

If finding enough time to exercise seems too much to contemplate, remember that any exercise is better than no exercise and small steps are the key to eventually making larger changes in your habits. What this means is that you shouldn’t forgo exercise altogether just because you can’t find the time or energy to exercise for 60 minutes a day -- even 30 minutes of exercise on most days of the week offers significant health benefits. Here are some strategies you can try to increase your amount of physical activity:

Exercise tip 1 -- Replace sedentary activities with more active ones.
For example, instead of watching television while sitting on the couch, take a walk while listening to a book on tape or talking on your cell phone. Or at least try doing some calisthenics while watching your favorite show.

Exercise tip 2 -- Look for stolen moments throughout your day to add activity.
Climb the stairs instead of taking the escalator, walk instead of taking your car or public transportation, do a lap around the mall before you start shopping, and return your cart all the way back to the supermarket instead of leaving it in the nearby cart bay.

Exercise tip 3 -- Buy a pedometer.
This step counter will help you assess how many steps you’re taking per day. We and other experts recommend 10,000 steps a day (equivalent to about 5 miles), although most people walk much less than that. Start off by tracking the number of steps you take on a typical day. Then, try to increase your step count by 500–1,000 steps every 2–3 weeks. Keep a record of your step counts and reward yourself (not with food, of course) when you reach your goal.

Exercise tip 4 -- Consider activities such as tennis, golfing, fishing, and dancing.
These activities can be enjoyed well into later life and add a social element to exercise.

Exercise tip 5 -- Plan for exercise every day.
Mark out 30 minutes or more a day for physical activity and stick to it as if it’s an important meeting or appointment. Individuals who become habitual exercisers are those who make physical activity a priority.

Calories Burned During Moderate vs. Vigorous Activities
Calories Burned Per Hour
for a 154-lb Person

Hiking 370
Light gardening/yard work 330
Dancing 330
Golf (walking and carrying clubs) 330
Bicycling (less than 10 mph) 290
Walking (3.5 mph) 280
Weight lifting (general light workout) 220
Stretching 180
Running/jogging (5 mph) 590
Bicycling (more than 10 mph) 590
Swimming (slow freestyle laps) 510
Aerobics Walking (4.5 mph) 460
Heavy yard work (chopping wood) 440
Weight lifting (vigorous effort) 440
Basketball (vigorous) 440

*People who weigh more than 154 lbs. will burn more calories per hour and people who weigh less than 154 lbs. will burn fewer calories per hour when engaged in the activities listed here. Source: Dietary Guidelines for Americans, 2005.

Finding Your Best Diet

Wed, 28 May 2008 06:00:00 CDT

The limited research on popular weight-loss plans drives home two messages: (1) weight loss is hard, and (2) finding the optimal diet for you as an individual is the only way to succeed. Here is some common-sense advice on how to choose a diet that suits you.

Long-term weight control is based on changing your eating patterns (and your physical activity habits) for a lifetime. Anyone can go on a diet for a couple of weeks, or even a couple of months, but those who lose weight and keep it off adopt a diet plan they can sustain (with some calorie adjustments) for years. Here, then, are some tips on how to choose a diet that suits you:

Diet Tip 1 -- Do a self-assessment.

Most overweight people eat out of habit and in response to emotions rather than because they’re hungry. To learn what leads you to overeat, observe your usual diet for a week: Keep track of what you eat, when and where you eat, who you’re with when you eat, and how you’re feeling when you eat. Also make note of your portion sizes (many overweight people eat larger portions and more calories than they think).

This process will give you an idea of your trouble spots and help you decide what diet plan will work best for you. For example, if your portion sizes are too large, you might find that a diet program that provides prepackaged or prepared meals, because you won’t need to make decisions about portion size.

If you are an emotional eater, a diet plan that offers counseling or support groups might be best for helping you cope with the emotional issues that are driving you to overeat.

Diet Tip 2 -- Find a diet that fits your personality and lifestyle.

You might be the type of person who is most comfortable with a diet that provides daily menus and recipes -- or you might prefer a plan that offers lists of foods from which you can pick and choose (or even provides prepackaged foods). You might require a diet plan that addresses some of your health concerns -- the need to lower your sodium, cholesterol, or fat intake -- or allows you to eat meals away from home because you travel a lot.

Diet Tip 3 -- Choose a diet that is well balanced.

Trendy diets such as the Atkins plan may produce quick weight loss, but they don’t offer the full complement of vitamins, minerals, and other nutrients your body needs to stay healthy -- and they typically lead to weight regain when you go off the diet. These diets are also hard to stay on for the long term because they strictly limit the types of foods you can eat. The best strategy is to go on a calorie-controlled diet plan that includes all of the food groups and doesn’t deprive you of your favorite foods.

Where's the D?

Wed, 18 Jun 2008 06:00:00 CDT

Vitamin D is an essential vitamin, helping to build strong bones and reducing the risk of osteoporosis. Here's advice on getting your daily dose of vitamin D.

Compared with most other vitamins, vitamin D is found naturally in only a few foods -- specifically, fatty fish such as salmon, mackerel, sardines, and tuna. In addition, milk, some orange juices, and some breakfast cereals are fortified with vitamin D.

However, food is not the only way to get your vitamin D. You can take supplements containing the vitamin, and your skin can synthesize vitamin D from sunlight.

How Much Vitamin D Is Enough?
The National Academy of Sciences recommends that people age 50 and under consume at least 200 IU of vitamin D each day, those ages 51–70 consume 400 IU daily, and those age 70 and older, 600 IU a day.

The latest dietary guidelines recommend even more -- 1,000 IU -- for older individuals (whose bodies are not as efficient at absorbing vitamin D from foods or supplements or making vitamin D from sunlight), those with dark skin (who naturally make less vitamin D from sunlight), and those who live in northern climates or are housebound (and thus have minimal sun exposure throughout the year).

The Best Ways To Get Your Vitamin D
The best way to get vitamin D is to combine foods rich in this vitamin with a multivitamin or other vitamin D–containing supplement.

For example, you can easily meet the National Academy of Sciences’ vitamin D recommendation by having a bowl of vitamin–D fortified cereal with half a cup of vitamin D–fortified milk (90 IU) for breakfast, a glass of vitamin D–- fortified orange juice (100 IU) or soymilk (120 IU) sometime during the day, and a multivitamin or vitamin D supplement (most contain 400 IU).

If you want to reach the higher dietary guidelines goal of 1,000 IU, take a second vitamin D supplement or eat fatty fish (200–360 IU) more often. Another option: Expose your face, arms, or legs to 10–15 minutes of sunlight without sunscreen two to three times a week. This is not the most efficient way to get your vitamin D, however. The skin’s ability to synthesize vitamin D decreases with age, and many people live in parts of the United States without year round sunshine.

Furthermore, the American Academy of Dermatology doesn’t advocate unprotected sun exposure as a means of getting adequate vitamin D, because of the risk of skin cancer -- although it’s unlikely that you’ll get skin cancer from such brief periods of unprotected sun exposure, particularly if you alternate sites of exposure and apply sunscreen afterward.

Should You Take a Multivitamin?

Wed, 16 Apr 2008 06:00:00 CDT

Most people are able to meet their nutritional needs by eating a variety of nutrient-packed foods. While there is little evidence that the average person benefits from the daily use of a multivitamin-mineral supplement, there also is little evidence of harm from taking supplements that do not exceed 100% of recommended intakes of nutrients.

A multivitamin-mineral supplement may help to fill nutritional gaps in your diet. Don’t forget, however, that a multivitamin supplement is not a substitute for eating a balanced diet rich in unprocessed whole foods that are naturally full of thousands of potentially health-promoting substances that supplements don’t contain.

With a few exceptions, not enough evidence exists to recommend for or against the use of multivitamin-mineral supplements. That was the conclusion of a panel of experts convened by the U.S. government and reported in the Annals of Internal Medicine (Volume 145, page 364).

The experts reviewed data from well-designed trials that examined the use of multivitamin-mineral supplements in healthy adults. Overall, they found insufficient evidence that these multivitamin supplements offer benefits to the general population. Yet there were some data to suggest that supplements containing zinc and antioxidants slow the progression of age-related macular degeneration but only in those with a moderate form of this eye disease.

For individual supplements, the panel called the evidence "encouraging" for the bone density-building effects of calcium and vitamin D in postmenopausal women. They also found enough evidence to advise against the use of beta carotene in smokers, because of an increased risk of lung cancer.

But the firmest recommendations from the panel had to do with the need for better research on the benefits and composition of multivitamin-mineral supplements and the possible interactions they can have with medications. So for now, unless you have age-related macular degeneration or are at risk for or have low bone density, it's possible that taking a multivitamin-mineral supplement may offer no health benefits.

Portion Size, Calories, and Weight Loss

Wed, 26 Mar 2008 06:00:00 CST

Perceptions of normal portion size have ballooned over the past 20 years -- increasing by 20 - 40% and adding substantial calories to our daily totals. And according to a recent study, the larger the size of a fast-food meal, the more likely that you will underestimate its calorie content.

Permanent alterations in your lifelong attitudes toward diet and exercise are the keys to successful weight management. You must be motivated enough to change habits not for a few weeks or months, but for a lifetime.

The first step is to determine how many calories you should eat each day. To do this, calculate the number of calories needed to maintain your current weight. This is roughly 15 calories per pound of body weight for a moderately active person (someone who gets at least 30 minutes of moderate to intense physical activity every day). A completely sedentary person requires just 12 calories per pound to maintain weight.

So how many calories do you consume in a meal? In a recent study reported in the Annals of Internal Medicine (Volume 145, page 326 ), researchers found that the larger the size of a fast-food meal, the more likely that you will underestimate its calorie content -- by as much as 500 calories.

The researchers conducted two experiments. One involved 105 people at fast-food restaurants, who were asked to estimate the calorie content of the meals they ordered and ate. The other, a laboratory study, enrolled 40 college students who were shown 15 different sizes of the same fast-food meal and asked to estimate the calorie content.

The results showed that the size of the meal was critical for getting the calorie count right: At the fast-food restaurant, those eating smaller meals estimated they were eating 419 calories when they consumed 514 calories. Those eating larger meals estimated 675 calories but actually ate 1,188 calories. In the laboratory study, students guessed large meals contained an average of 1,000 calories when they really had 1,382 calories and that small meals contained 631 calories when they had 655 calories. In the two experiments, both overweight and normal-weight participants underestimated the calories in larger meals.

The bottom line: The next time you eat a super-size meal, be aware that its calorie count is probably twice what you think it is.

Soft Exercises That Count

Wed, 05 Mar 2008 06:00:00 CST

Exercise doesn't have to be a chore to offer health advantages. The latest studies suggest that "soft” exercises, such as yoga, dog walking, and gardening, can help you manage your weight.

Most of these soft exercise activities are not extra-large calorie burners. But they do get you up and moving and away from the TV and fridge. Here are few exercises you might try to lose weight and enjoy yourself.

Yoga -- Yoga is a great way to relax and reduce stress, and new research shows that it may also help control weight. In a recent study of more than 15,000 middle-aged people, those who did yoga for at least half an hour a week for four or more years were better able to fight off weight gain.

Although a vigorous yoga session can burn up to 250 calories, the energy expenditures related to yoga itself were probably not responsible for the lack of weight gain seen in the study. Rather, it's more likely that taking up yoga makes you more mindful of what you’re eating and of your body and health in general. In addition, yoga can improve breathing, strength, and flexibility, making you more apt to perform other types of physical activity and lose weight.

Walking the Dog -- Dogs are more than delightful companions -- they can help with weight control. In a 2005 study, researchers at the University of Missouri-Columbia found that disabled people who started off walking a dog for 10 minutes three times a week, and worked up to 20 minutes five times a week, lost an average of 14 lbs over the course of a year -- without purposefully changing their diets. Most weight-loss programs can’t boast of those kinds of results.

Another study, conducted at Northwestern University, found that people who went on a weight-loss and fitness plan together with their dog lost 11 lbs over the course of a year. Diet and exercise with your dog? That’s right. Like humans, many dogs are overweight, so involving your pooch in your weight-loss efforts can be beneficial for both you and your dog.

Other Soft Exercises -- Light gardening and yard work can be surprisingly taxing: Performed at a moderate pace, a 154-lb person can burn 330 calories per hour digging up weeds and raking. A similar case can be made for dancing and golfing (when you walk and carry your clubs). Biking at a moderate pace (less than 10 miles per hour) can burn 290 calories an hour, while walking at 3.5 miles per hour can burn 280 calories an hour. Swimming slow freestyle laps can burn a whopping 510 calories per hour.

If you’re exercise averse, look for activities that you enjoy or that allow you to socialize, such as doubles tennis or fly fishing with a friend. Consider joining a walking club or taking a class (gentle yoga or tai chi, perhaps). In short, look for the fun in moving more as you strive to make activity a part of your everyday life.

Are Fresh-Cut Fruits Less Nutritious Than Whole Fruits?

Wed, 13 Feb 2008 06:00:00 CST

Looking for a way to up your consumption of fresh fruit? A recent study confirms that fresh-cut fruit stays fresh and nutritious for up to 6 days in the supermarket.

Fruits, vegetables, and other plant foods are packed with ingredients in addition to vitamins, minerals, and fiber. From anthocyanins (the red pigment in strawberries and cherries) to allylic sulfides (which are responsible for the pungent flavor of garlic and onions), these compounds, which are also known as phytochemicals, may be responsible for some of the disease-preventing effects of fruits and vegetables. Phytochemicals have no nutritive value -- that is, they are not vitamins or minerals -- but they may have positive effects on the body over the long term. Possible beneficial effects include inhibiting tumor formation, preventing blood clots, blocking the cancer-promoting effect of certain hormones, and lowering cholesterol levels.

While fresh-cut fruits from the supermarket are one of modern life’s conveniences, there’s been concern that cutting might lessen the amount of nutrients you’ll get from eating these fruits. Not so, according to the results of a recent study, reported in the Journal of Agricultural and Food Chemistry (Volume 54, page 4284).

The researchers looked at fresh-cut and whole pineapples, mangoes, cantaloupes, watermelons, strawberries, and kiwifruits that were stored for up to nine days at 41° F. Most of the fruits still looked fresh for about a week after cutting. While kiwifruit lasted less than six days, pineapple, cantaloupe, and strawberries lasted six to nine days, and watermelon and mango lasted over nine days.

After six days, the fresh-cut fruits retained 75–95% of their vitamin C content, 75–100% of their carotenoids, and all of their phenolics. Mango, strawberry, and watermelon pieces retained the most vitamin C, and kiwifruit and watermelon didn’t lose any carotenoids. Exposure to light affected some fruits, leading to browning of pineapple pieces and a loss of vitamin C in kiwifruit slices. Based on these findings, feel free to take advantage of fresh-cut fruit. They are likely to look spoiled before any significant nutrient loss occurs.

The Obesity Vaccine

Wed, 12 Dec 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Obesity Vaccine

Researchers are trying to develop a vaccine that suppresses ghrelin -- a hormone secreted by the gut into the blood that acts on the brain to stimulate appetite.

Eating more calories than you expend is an important cause of obesity. In fact, regardless of your genetic predisposition to obesity or your resting metabolic rate, you cannot gain weight without consuming more calories than you burn.

To point to overeating as the cause of obesity is overly simplistic, however. It does not explain why a 125-lb woman can eat 1,800 calories a day and not gain weight, while another 125-lb woman struggles to avoid gaining weight on 1,200 calories a day. This difference occurs because numerous other factors contribute to weight gain, including resting metabolic rate and physical activity. Nevertheless, obese people must be consuming more calories than required by their individual make-ups and activity levels. Otherwise they would not store excess body fat. Thus, if you’re overweight, you must reduce your calorie intake to lose weight.

Now there’s promising news for people struggling to keep weight under control: Researchers are trying to develop a vaccine against obesity using antibodies to the appetite-stimulating hormone ghrelin. The obesity vaccine shows promise in rats, according to a recent study reported in the Proceedings of the National Academy of Sciences (Volume 103, page 13226).

Ghrelin is a hormone secreted by the gut into the blood that acts on the brain to stimulate appetite. In rats, the hormone also decreases energy expenditure and slows the breakdown of fat. But rats deficient in ghrelin or lacking a receptor for the hormone store less of the food they eat and fail to gain weight when placed on a high-calorie diet.

In the study, the researchers prepared three different antibodies to ghrelin and tested them in 17 male rats as a possible vaccine against weight gain. The vaccinated rats were allowed to eat as much as they wanted, but the rats given two of the three vaccines gained less weight, maintained muscle mass, and lost body fat compared with the control mice. The third vaccine was ineffective.

Although the results are encouraging, the research is preliminary. And just because something works in rats does not mean that it will have the same effect in humans. In fact, in humans (especially obese people) appetite is not the only trigger to eat -- emotions, habit, and stress, for example, also play a role -- so a vaccine that quenches appetite may not have significant or lasting benefits in humans.

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Obesity Vaccine

The Value of Soy

Wed, 02 Jan 2008 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Value of Soy

A panel of experts from the American Heart Association questions the benefits of consuming soy-based foods and supplements to reduce cardiovascular risk ... and offers bottom-line advice.

Tofu, soy protein, soymilk, soy flour, soy butter, and edamame (edible green soybeans) are all phytochemicals -- compounds from plant goods that may help to lower the risk of certain diseases. Tofu and other soy products are mild tasting and pick up the flavor of the foods they are cooked with. For example, tofu can be stir-fried with vegetables or added to soups. Soy flour can substitute for up to one quarter of the flour in baking recipes, and soy butter can be spread on bread in place of peanut butter.

Soy-based foods and supplements have been touted as a way to lower cholesterol levels and reduce cardiovascular risk. But a review of 22 randomized trials by a panel convened by the American Heart Association (AHA) does not support earlier evidence that soy protein or the isoflavones it contains produces large benefits on blood lipids or blood pressure. These findings were reported in the journal Circulation (Volume 113, page 1034).

The review found that consumption of soy protein with isoflavones at a high dose of about 50 g a day (about half of the usual daily protein intake) reduced low-density lipoprotein (LDL) cholesterol levels by only about 3% and had no significant effect on high-density lipoprotein (HDL) cholesterol, triglycerides, or blood pressure. In the area of women’s health, soy was not found to lessen hot flashes associated with menopause. Results were mixed on its ability to slow postmenopausal bone loss. And the isoflavones in soy had no proven effect in preventing or treating breast, uterine, or prostate cancer. Based on these results, the AHA panel does not recommend getting isoflavones from food or pills.

However, all is not lost: The panel says soy protein is still a good substitute for animal protein, because soy-containing foods have a high content of vitamins, minerals, fiber, and polyunsaturated fats.

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Value of Soy

Are You Getting Enough Liquids?

Wed, 31 Oct 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Are You Getting Enough Liquids

As we age, our thirst response is blunted. As a result, many older Americans may not be drinking enough water and may be at risk for dehydration, according to a report in the American Journal of Nursing (Volume 106, page 40).

Water is an essential nutrient because it is involved in all the processes in your body. Since water needs vary with diet, physical activity, environmental temperature, and other factors, it is difficult to pin down an exact water requirement. Changes in the body that accompany aging can make you vulnerable to shifts in water balance. In fact, when 35 nursing home residents were followed for six months, a third of them were found to be dehydrated -- they had not drunk enough water and other liquids, had lost too much fluid, or both.

Potential consequences of dehydration include constipation, falls, drug toxicity, urinary tract infections, longer healing times for wounds, and even hospitalization. The cue to drink, known as the thirst response, is blunted with age. At the same time, the body uses water less efficiently as we get older. Certain medications (such as diuretics and laxatives), cognitive impairment, and many illnesses (including diabetes, cancer, heart disease, and infections) also raise the odds of dehydration.

Water is a great liquid to consume, but you can also obtain fluids from fruit juices, low-sodium soups, decaffeinated coffee and tea, and water-rich fruits (watermelon, berries, and grapes) and vegetables (tomatoes and lettuce). The Institute of Medicine recommends about 11.5 cups of fluid a day for women and 15.5 cups for men, which includes water in food. (About a fifth of your fluid intake comes from food.)

Johns Hopkins Health Alerts | Nutrition and Weight Control | Are You Getting Enough Liquids

Why Americans Are Too Fat

Wed, 21 Nov 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Why Americans Are Too Fat

Weight control is far more complex than simply balancing calories consumed with energy expended. Here are 10 top (alternative) reasons why Americans are overweight – and some may surprise you.

Rates of obesity are higher than ever in the United States. According to the Centers for Disease Control, more than six in 10 American adults are overweight or obese -- and most adults are about 25 lbs heavier than people were in the 1960s. To make matters worse, more than half of all overweight people actually think they’re at a healthy weight, according to a recent Associated Press poll.

In theory, weight control is a simple matter of balancing energy intake (the calories supplied by food) with energy output (the calories expended by physical activity, the digestion of food, and the functioning of your body). To lose weight, you need to expend more energy than you take in. In practice, however, the task is not that simple. While the basic principle of energy balance remains true, several mechanisms -- genetic, metabolic, and environmental -- can affect how much you eat and how your body uses and stores energy.

A revealing study published in the International Journal of Obesity (online edition, June 27, 2006) highlighted 10 reasons why Americans are fat. The study explained that too much food and a lack of exercise are not the only factors contributing to obesity. They identified 10 other possibilities:

Weight gain factor 1. Less sleep. We’ve gone from an average of nine to seven hours of sleep a night; sleep deprivation is linked to a more robust appetite.

Weight gain factor 2. Pesticides and other chemicals in foods. These substances can change hormonal activity, which can boost body fat.

Weight gain factor 3. Air conditioning and heating. We don’t sweat and shiver as much as our ancestors, so we don’t burn as many calories.

Weight gain factor 4. Fewer smokers. Nicotine is an appetite suppressant.

Weight gain factor 5. Greater use of medications, such as antidepressants and diabetes drugs, which have weight gain as a potential side effect.

Weight gain factor 6. Population changes. There are now more older people as well as more Hispanics in the United States, and these groups have higher rates of obesity.

Weight gain factor 7. Older birth mothers, whose children are more prone to excess weight gain than the offspring of younger mothers.

Weight gain factor 8. Genetics. Obese moms may pass the trait onto their children in utero.

Weight gain factor 9. Higher body weight = greater fertility. Heavy people produce more offspring than thinner people.

Weight gain factor 10. Assortative mating. Heavy people tend to mate with each other and produce heavy children.

For more Alerts and Special Reports, please visit the Nutrition & Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Why Americans Are Too Fat

The Pros and Cons of Functional Foods

Wed, 29 Aug 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Pros and Cons of Functional Foods

Functional foods have some health benefits, but functional foods are not a substitute for a healthy lifestyle or any medications your doctor may prescribe.

Peruse the shelves of your local supermarket and you're sure to find a proliferation of functional foods -- products that contain ingredients that purportedly offer health benefits, from lowering blood pressure and cholesterol to boosting your body’s immune system. But do these health products really provide the benefits their labels tout? Here we look at three functional foods to let you know the pluses and minuses of each.

Functional Food 1: Activia Yogurt
Health claim: Helps naturally regulate your digestive system.
Functional food ingredient: Live cultures of the bacterium Bifidus regularis.
Evidence for claim: Not much. All the research has been done by Dannon, the makers of Activia. This research shows that, when eaten on a daily basis, Activia decreases transit time (how long it takes for food to pass through the digestive tract) by up to 40%. When food moves slowly through your digestive tract, it can lead to constipation and abdominal discomfort.
Pluses: Contains only 110 calories per 4-oz serving and is low in fat. One 4-oz serving has 15% of the daily recommended amount of calcium. Activia contains no artificial flavors or colors.
Minuses: Dannon recommends one serving (4 oz) a day, but more research is needed to determine the minimum beneficial dose. More research is also needed to definitely say this product has the intended effect. However, it is safe to try Activia to see if it helps keep you regular. Another minus: It contains added sugar.

Functional Food 2: Nature Valley Healthy Heart Chewy Granola Bars
Health claim: Helps keep your heart healthy.
Functional food ingredient: 0.4 g of plant sterols.
Evidence for claim: Many studies show that eating 2 g of plant sterols on a daily basis as part of a diet low in saturated fat and cholesterol helps lower blood cholesterol levels.
Pluses: Contains oats and barley, which are whole grains. Contains 3 g of fiber per serving. Low in saturated fat (only 0.5 g).
Minuses: To see a cholesterol-lowering effect, you will need to eat five granola bars every day. That comes at a daily cost of about 750 calories. The granola bars are also high in sugar.

Functional Food 3: Tropicana Pure Premium Essentials Orange Juice With Fiber
Health claim: Helps your digestive system stay healthy and regular.
Functional food ingredient: Fibersol-2, a fiber derived from corn.
Evidence for claim: Research shows that fiber adds bulk to and softens the stools, which may help prevent constipation.
Pluses: An 8-oz glass contains 3 g of fiber (as much as a medium sized orange). Regular orange juice contains no fiber. Good source of vitamin C, folate, and potassium.
Minuses: Why not just eat a medium- sized orange instead? It has just as much fiber for half of the calories (60 vs. 120 calories). In addition, the latest dietary guidelines recommend that most of your fruit servings come from whole fruit.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Pros and Cons of Functional Foods

Tips on Getting Your 2-4 Cups of Vegetables a Day

Mon, 13 Aug 2007 10:03:32 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Tips on Getting Your 2-4 Cups of Vegetables a Day

Even if you’re not a vegetable fan, there's a lot you can do to get the recommended 2-4 cups of vegetables a day.

Your whole life you’ve been told, "Eat your vegetables!” And it’s good advice. Vegetables contain nutrients that are essential to your health and may reduce your risk of a myriad of chronic diseases from heart disease to diabetes and some cancers. The latest food pyramid recommends that you eat 2-4 cups of vegetables a day (the exact amount depends on your age, gender, and activity level). But that’s not always an easy task. Here, then, are some ideas from the experts on how to get your veggies -- and enjoy them, too.

When Shopping for Your Vegetables:

Buy fresh vegetables in season. Vegetables will be at the height of their flavor and cost less than at other times of the year.

Buy bagged and/or precut produce. It may be a bit more expensive, but the time and effort you save can be worth the additional cost, particularly if you have arthritis, low vision, or another health problem that makes cutting and preparing vegetables difficult.

Buy vegetables that don’t need to be cut, such as baby carrots, grape tomatoes, cauliflower, sugar-snap peas, baby spinach leaves, and asparagus.

Shop the frozen foods aisle. Frozen vegetables are high in nutritional value because they’re frozen within hours of being picked.

Peruse the salad bar. Just stay away from the mayonnaise- and oil-based salads (pasta and potato salads, for example) and stick to low-calorie items such as greens, tomatoes, carrots, peppers, and cucumbers. There’s a caveat to the salad bar, however. A sneeze or someone’s fingers can contaminate the food, increasing the risk of getting a foodborne illness. This usually isn’t a problem for healthy people, but if you have a weakened immune system, the convenience of the salad bar may not be worth the risk.

Go ethnic. Try water chestnuts and bok choy for Asian flair, jalapeno peppers and corn for a Mexican-style dish, or savory cabbage for Thai cuisine. Mixing up your vegetables can help fight vegetable boredom.

When Preparing Your Vegetables:

Try precooking vegetables. Buy fresh vegetables and partially cook them as soon as you get them home from the store. To do this, blanch the vegetables in boiling water until they’re half done, let them cool, and then store them in resealable plastic bags in the refrigerator. When you’re ready to eat the vegetables, simply sauté them with a little olive oil and some herbs and spices until they’re fully cooked.

Use a good knife. Be sure to keep knives sharp so they cut easily.

Try the microwave. You can bake white or sweet potatoes in just minutes in the microwave. Frozen vegetables can be quickly prepared in this way, too.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Tips on Getting Your 2-4 Cups of Vegetables a Day

Easy Ways to Keep Vegetables Safe

Wed, 19 Sep 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Easy Ways to Keep Vegetables Safe

Here are 10 practical tips to help you avoid foodborne illnesses while you enjoy your vegetables.

Meat, poultry, and eggs are not the only foods that can cause foodborne illnesses. According to the Centers for Disease Control and Prevention (CDC), contaminated vegetables (and fruits) also are to blame. Follow these guidelines for safe vegetable preparation from the CDC’s FightBac! campaign:

Vegetable guideline 1: Do not buy vegetables that are bruised or damaged. If blemishes or soft spots develop after buying, remove them before eating.

Vegetable guideline 2: Avoid precut vegetables or packaged salads that are not refrigerated.

Vegetable guideline 3: Wash your hands with warm water and soap for 20 seconds before and after handling fresh vegetables.

Vegetable guideline 4: Clean all surfaces and utensils (including cutting boards, countertops, peelers, and knives) with hot water and soap before and after using them to prepare vegetables.

Vegetable guideline 5: Rinse all vegetables under cold running water for two minutes. This includes vegetables that have skins you don’t plan to eat (such as cucumbers), since bacteria can travel from the vegetable’s skin to the flesh during cutting. Detergent and bleach are not necessary and could be harmful to your health if ingested.

Vegetable guideline 6: For potatoes, carrots, and other root vegetables, scrub the skin with a clean brush while running under cold water.

Vegetable guideline 7: Should you wash bagged salads and other packaged precut vegetables that say “ready to eat” or “washed”? The CDC’s FightBac! campaign doesn’t mention anything about these products, but some food safety experts recommend washing them as a precaution. So the decision is up to you.

Vegetable guideline 8: Sprouts are another food not mentioned in the FightBac! campaign, but bacteria can grow inside sprouts and are difficult to wash out. We recommend that you always cook sprouts, and at restaurants and delis ask that sandwiches and salads be made without raw sprouts.

Vegetable guideline 9: Keep raw foods, such as meat, poultry, and seafood, separate from fresh vegetables -- in your grocery cart, in the refrigerator, and when preparing meals. In addition, use separate knives and cutting boards for vegetables and raw foods to prevent cross-contamination.

Vegetable guideline 10: Refrigerate all cut, peeled, and cooked vegetables within two hours. Vegetables left at room temperature for longer than two hours should be thrown out.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Easy Ways to Keep Vegetables Safe

Nuts for Nuts

Wed, 18 Jul 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Nutritional Value of Nuts

In terms of protein, total fat, and calories, 1 oz of nuts is roughly equivalent to 2 oz of lean meat plus 2 tsp of vegetable oil. Nonetheless, the health benefits of nuts are considerable, as Johns Hopkins nutritionist Lora Brown Wilder explains.

Ask any nutritionist today about nuts, and he or she will tell you they are good for you -- in moderation, of course. That’s a whole new way of thinking about nuts, which for years were perceived as "bad" foods because of their high fat and calorie content. But a slew of recent studies have brought a better understanding of nuts’ health benefits. The turnaround has been so dramatic that packages of some nuts have labels approved by the U.S. Food and Drug Administration touting the possible heart benefits of nuts, and the most recent dietary guidelines mention nuts as good sources of protein and mono- and polyunsaturated fats.

Why Nuts Are Good for You
Nuts pack a powerful nutritional punch. Nuts contain monounsaturated fats, which help lower low-density lipoprotein (LDL, or "bad”) cholesterol and may raise high-density lipoprotein (HDL, or “good”) cholesterol when substituted for saturated fats in the diet. So it’s not surprising that several major studies have found that eating nuts significantly reduces the risk of coronary heart disease -- by 25–50% in both men and women. One of these studies, the Nurses' Health Study, also found that regularly eating nuts and peanut butter reduces the chance of developing type 2 diabetes by 21–27%.
Besides monounsaturated fats, nuts are rich in vitamins, minerals, and other substances that are beneficial to your health. For example, walnuts contain a type of omega-3 fat similar to fish oil, and almonds contain calcium and vitamin E. Nuts are also good sources of protein and fiber.

Nuts and Weight Control
It sounds paradoxical, because they're calorie dense (160–200 calories per oz), but research shows that people who eat nuts tend to weigh less than those who don’t eat nuts. Possible explanations: Nut eaters may follow a healthier diet (lower in calories and saturated fat) than people who abstain from nuts, and those who are overweight may shun nuts because of their high-calorie content.
But other factors also may come into play. Nuts are quite filling because of their high protein and fiber content. In one study, subjects who snacked on nuts and peanut butter weren’t hungry for 2.5 hours afterward and, interestingly, spontaneously adjusted their calorie intake for the rest of the day so they didn’t consume extra calories.

Protein also requires more energy to digest than fats or carbohydrates, so you use up more calories in the process. Also, because people tend not to chew nuts fully before swallowing them, they aren’t well digested and some of the calories they contain may be lost in the stool.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Nutritional Value of Nuts

The Truth About Trans-Fat Free

Wed, 08 Aug 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Truth About Trans-Fat Free

How can you keep your intake of trans fat to the recommended 2g or less a day? Try these trans fat-free products.

By now you’ve probably heard that trans fat is one of the unhealthiest fats in the American diet. That's because trans fat not only raises low-density lipoprotein (LDL, or "bad") cholesterol but trans fat also lowers the "good" high density lipoprotein (HDL) cholesterol. In fact, trans fat is so harmful to your health that the Institute of Medicine says there is no safe level of intake and recommends consuming as little trans fat as possible.

The American Heart Association has put a number on "as little as possible," advising Americans to keep their trans fat intake below 1% of total calories. On a 1,800-calorie-a-day diet, that's less than 2 g of trans fat a day. To make it easier for you to reduce trans fat intake (it’s virtually impossible to consume no trans fat at all), the U.S. Food and Drug Administration now requires food manufacturers to list the amount of trans fat on the Nutrition Facts panel. (The amount is listed beneath the entry for saturated fat.) What's more, food manufacturers have developed trans-fat–free versions of many of our favorite foods.

The Frito-Lay Company, for instance, is cooking Cheetos, Doritos, Sun, and Lays chips in corn and sunflower oils instead of hydrogenated oil to get out the trans fat. Likewise, Kraft has refashioned their reduced-fat Oreo cookies to lose the trans fat and eliminated most of the trans fat from Triscuits, Wheat Thins, Chips Ahoy, Mallomars, Boca products, and Honey Maid low-fat Cinnamon Grahams. The same is true for some Girl Scout cookies, including the ever-popular and delectable Thin Mints.

Kellogg has reduced trans fat in their Pop Tarts and Cheez-It crackers by using soybean oil, which lessens the need for hydrogenated oil, while Gorton's is frying its fish sticks and fillets in healthier oils. Even Crisco shortening now comes in a trans-fat–free formulation.

Unlike food manufacturers, most restaurants and food chains in the United States continue to use hydrogenated fats to fry French fries and other fast foods. If you're looking for chains that are breaking away from trans fat, try Au Bon Pain, Jason's Deli, Panera Bread, California Pizza Kitchen, and Wendy's, to name a few. On the grocery side, you can find trans fat –free foods at Whole Foods stores. In fact, the chain has never sold products with partially hydrogenated oils. Other chains, such as Wegman's, Raley's, and Giant stores, are making gradual changes to healthier fare.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Truth About Trans-Fat Free

Downsizing Your Plate To Reduce Weight

Wed, 06 Jun 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Downsizing Your Plate To Reduce Weight

7 Tips on feeling satisfied when cutting calories

Clean your plate! It’s a mantra in America, and a contributor to the ever-increasing obesity problem. A major part of the obesity problem is portion sizes, which have grown substantially over the past four decades: A Coke has increased from 6.5 to 20 fl oz. or more, a bagel from 2–3 to 4–6 oz., and a chocolate bar from 1 to 1.5–8 oz.

Another part of the obesity problem is satiety; we often just don’t feel full when we control our calories. According to researcher Barbara Rolls, Ph.D., a nutritionist at Pennsylvania State University and co-author of The Volumetrics Weight-Control Plan, “Satiety is the missing ingredient in weight management. Cut calories simply by eating less and you’ll feel hungry and deprived.”

Here are some weight control strategies for controlling your portion sizes while still eating enough to feel satisfied.

Weight Control Tip 1 -- Know Your Portion Sizes. There’s a difference between serving size and portion size. A serving is a standard amount of food containing a set amount of calories; a portion is what you actually put on your plate. So a portion could be a lot more than a single serving -- and therefore contain a lot more calories than you might expect.

Weight Control Tip 2 -- Check Food Labels Closely. You can’t assume a package contains a single serving just because the label lists calorie and nutrient information for one serving. Look for the number of servings per package (it’s listed directly under the serving size) to determine the true calorie count.

Weight Control Tip 3 -- Divide and Conquer. Research shows that the bigger the plate, bag, or container of food, the bigger your eyes (and it appears that the eyes have more control over how much you eat than your stomach).

Weight Control Tip 4 -- Go High Fiber, High Water. Eat foods that have a high water and/or high fiber content and are low in fat. This is the key concept behind Dr. Rolls’ Volumetrics approach. Soups, salads, stews, casseroles, fruits, vegetables, low-fat milk, cooked grains, and beans are all good choices. These “wet” foods have a low energy density -- meaning the water and fiber they contain will fill you up with a small amount of calories -- as opposed to “dry” foods like cookies, cereal, and crackers, which have a high energy density.

Weight Control Tip 5 -- Start Meals with Soup or Salad. Dr. Rolls has found that people tend to eat less when they precede a meal with a low calorie soup or salad (with fat-free dressing).

Weight Control Tip 6 -- Eat a Variety of Foods. Dr. Rolls’ research reveals that even when you’re full from one type of food, say a salty snack, you can still make room for another type of food, say a sweet dessert. By eating a small amount of different-tasting foods, you can create a sense of fullness without a lot of calories.

Weight Control Tip 7 -- Emphasize What You Can Eat, Not What You Can’t. Positive thinking extends to weight management, too: After all, diets often fail because we feel deprived. By focusing on what you can eat, you’ll feel better about your weight loss program than if you focus on all you’re missing.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Downsizing Your Plate To Reduce Weight

Can You Be Fat But Fit?

Wed, 25 Apr 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Can You Be Fat But Fit

Is it possible that being overweight but fit is a healthier scenario than being thin and sedentary? Johns Hopkins cardiologist Ty J. Gluckman, M.D. discusses this intriguing question.

Everyone knows that it’s unhealthy to be very overweight. But what if you are obese but still relatively physically fit? Does being fit cancel out the health risks of being obese, or at least some of them? In other words, is it possible that being obese isn’t the real problem, but rather being unfit?

Although some obese people, as well as some researchers, make this claim, there are no easy answers to these questions. First, it’s hard to define the terms. Overweight and obesity are usually defined in terms of body mass index (BMI), which is an imperfect gauge of body fat. Physical fitness varies from person to person and by age. Fitness means different things to a dancer, lumberjack, mailman, or weight lifter. But for researchers, fitness is generally defined as cardiovascular (aerobic) fitness -- the ability to carry on a vigorous activity such as running or brisk walking for an extended period.

Obese people face many increased risks -- for diabetes, high blood pressure, and high cholesterol, all of which boost the risk for cardiovascular disease. Obese people also face an elevated risk for many types of cancer and several other diseases. Thus, obese people, almost across the board, have significantly lower life expectancy than leaner people.

However, there is some evidence that for obese people who are fit, the risks are less dramatic. For instance, in a study looking at more than 5,000 men and women (age 30 to 75), researchers at the University of North Carolina reported that being obese and being unfit both increase the risk for premature death, while fitness reverses some, but not all, of the increased risk associated with excess body fat.

Some of the best-known research on this subject comes from the Cooper Institute for Aerobics Research in Dallas. Its studies have reported that obese men who become fit lower their risks. Men who are obese and fit actually face lower risks than those who are lean but unfit. Therefore, when it comes to cardiovascular mortality, fitness may be more important than weight, at least for men.

Being sedentary and unfit are major contributors to being overweight and obese. And when overweight people start to exercise more, they usually lose weight (especially if they control their calorie intake) and lower their blood pressure and cholesterol levels. That’s why, in these studies, relatively few obese people are very fit. Most obese people don’t (or can’t) exercise much, and those who truly become fit tend to lose weight. Just because there are some fit, healthy obese people, you shouldn’t conclude that it’s healthy for most people to stay obese.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Can You Be Fat But Fit

On the Glycemic Index and Healthy Carb Choices

Wed, 04 Apr 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Glycemic Index and Healthy Carb Choices

Despite the negative publicity they’ve gotten over the past few years, all carbohydrates are not bad for your health.

You may have heard of the Glycemic Index, which measures how fast a carbohydrate is digested and raises blood sugar levels. The lower the glycemic value, the more staying power a food has and the longer it will suppress your appetite. The higher the Glycemic Index of a carbohydrate, the faster it is broken down in the intestine and the more quickly and dramatically it will raise your blood sugar level -- and the bigger the subsequent drop.

Some manufacturers like Kraft and Kellogg are marketing products that are “low glycemic” (a label that is replacing “low carb” claims as Atkins and other low-carb diets fade from popularity). In fact, the number of “low glycemic” product introductions has jumped sharply since 2003. While many say there’s better science behind the Glycemic Index than the low carb diet, the Glycemic Index is difficult to understand and deals with only single foods: It doesn’t take into account what happens when you eat more than one food at a time. So while an apple may have a low Glycemic Index value of 40, the bagel you eat it with, which has a Glycemic Index of 72, can change the balance enough to make the Glycemic Index irrelevant.

The bottom line: While the Glycemic Index is a good research tool, it currently does not have much application to real life. So ignore the packaging claims about Glycemic Index values and focus on fruits, vegetables, and whole-grains as the sources of carbohydrates in your diet.

The 2005 Dietary Guidelines for Americans recommends that half of the grains you eat be whole grains. Common whole grains include: brown rice, buckwheat, bulgur (cracked wheat), muesli, oatmeal, popcorn, whole grain barley, whole grain cornmeal, whole rye, whole wheat bread, pasta, crackers, sandwich buns and rolls, tortillas, and cereal flakes, wild rice. If you’re feeling adventurous, try cooking with or buying products that contain these less well-known whole grains -- amaranth, millet, quinoa. sorghum, triticale.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Glycemic Index and Healthy Carb Choices

The Dangers of Too Much Body Fat

Wed, 16 May 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Dangers of Too Much Body Fat

If you consume more calories than you expend, those extra calories will be stored primarily as fat regardless of whether the extra calories come from fats, carbohydrates, or proteins. Johns Hopkins experts explain the dangers of fat cell secretions.

It used to be thought that fat cells -- known as adipocytes in medical terminology -- were just storage bins for excess calories. Today, however, it is clear that adipocytes are very active cells that produce and secrete a wide variety of substances that play a key role in regulating body weight. But health problems can arise when these cells begin to secrete too much or too little of these substances.

You are born with a set number of fat cells. If you eat more calories than your body needs, your fat cells stretch to store these extra calories as triglycerides. You may even gain new fat cells when the cells have enlarged to their maximum size. Once created, however, fat cells remain in your body forever; they may shrink in size when you lose weight, but they never go away (unless they are removed by surgery or liposuction).

Fat cells normally produce a variety of substances that influence your body weight, how many calories you eat, and how those calories are used as a source of energy. This is an active area of investigation, and researchers have recently identified along list of these substances—with unwieldy scientific names such as leptin, interleukin-6, tumor necrosis factor alpha, angiotensinogen, adiponectin, and resistin.

When you have enlarged fat cells or too many fat cells, because you are overweight, many of these substances are released into the bloodstream at higher levels than normal. Over time, excessive amounts of the substances begin to damage blood vessels and tissues and impair blood flow, resulting in health problems such as diabetes, high blood pressure, liver disease, cardiovascular disease, and certain types of cancer.

Is there anything you can do to normalize the secretions from your fat cells? Yes, and losing weight is your best option. Weight loss shrinks fat cells back to their usual size, normalizes their secretions, and can reverse or prevent many of the health conditions associated with obesity. Some experts predict that doctors may one day be able to analyze your genetic make-up along with the products of your fat cells to see which compounds you’re over- or under-secreting, and design an individualized dietary plan to counter the adverse effects of abnormal levels of specific secretions. For some, that plan may involve a carbohydrate-rich diet; for others, a higher protein or healthy fat regimen. Till then, the usual diet and exercise plan is the best route to shedding pounds.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Dangers of Too Much Body Fat

The Overeating Conundrum

Wed, 21 Feb 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Overeating and Weight Gain

If you overate for a week or so and gained weight, would you automatically eat less than usual to lose those extra pounds? According to the results of a recent study, the answer may be “no.”

Eating more calories than you expend is an important cause of obesity. In fact, regardless of your genetic predisposition to obesity or your resting metabolic rate, you cannot gain weight without consuming more calories than you burn. Even small excesses in calorie intake can add pounds over the long term. For example, a person who overeats by just 25 calories a day will consume 9,125 excess calories over the course of a year and gain 2.5 lbs. (a pound of body fat is equivalent to 3,500 calories). A woman weighing 125 lbs. who starts this pattern at age 20 would weigh 175 lbs. by the time she is 40.

To point to overeating as the cause of obesity is overly simplistic, however. It does not explain why a 125-lb. woman can eat 1,800 calories a day and not gain weight, while another 125-lb. woman struggles to avoid gaining weight on 1,200 calories a day. This difference occurs because numerous other factors contribute to weight gain, including resting metabolic rate and physical activity. Nevertheless, obese people must be consuming more calories than required by their individual make-ups and activity levels; otherwise they would not store excess body fat. Thus, if you’re overweight, you must reduce your calorie intake to lose weight.

Overeating is the subject of an interesting study reported in the journal, Physiology and Behavior (Volume 84, page 669).

Researchers prepared meals for 12 normal-weight people for seven weeks. During the first two weeks, the participants were allowed to eat as much or as little as they wanted. For the next two weeks, they were purposely fed 35% more calories than they ate during the first two weeks, which resulted in a weight gain of about five lbs.

Next, they were told to return to eating as much or as little as they wanted for three weeks. Surprisingly, although the subjects had complained of “feeling stuffed” during the overfeeding period, they didn’t eat any fewer calories during the last three weeks than they did during the first two weeks of the study. Even so, they lost about half of the weight they had gained, most likely because their metabolic rate rose in response to the weight gain.

The researchers write that the absence of calorie cutting after overfeeding might have been related to eating in the same environment and being offered the same portion sizes as in the first two weeks of the study. Whatever the reason, this study points out that you cannot rely on being able to eat less after a period of overeating, and we recommend that you avoid overeating in the first place.

For more Alerts and Special Reports, please visit the Nutrition and Weight Control Topic page.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Overeating and Weight Gain

Are You Getting Enough Vitamin B?

Tue, 12 Dec 2006 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Benefits of Vitamin B and Folic Acid

How much is enough when it comes to B vitamins? Here are recommendations from Johns Hopkins.

B vitamins are vital for the breakdown and utilization of carbohydrates, fats, and proteins, and B vitamins also help to ensure proper functioning of the nervous system and the synthesis of red blood cells and genetic material. Folic acid, one of the B vitamins, is essential during the early months of pregnancy to prevent birth defects, such as spina bifida and cleft palate.

Older adults typically have greater requirements for certain B vitamins, particularly vitamins B6 and B12. Many older people have poor quality diets, and so don’t get enough vitamin B6. And some experts estimate that 10–30% of older adults are unable to absorb vitamin B12 efficiently from food because of alterations in the cells lining the digestive tract or reduced secretion of a substance called intrinsic factor that is needed to absorb vitamin B12. A lack of vitamin B12 can cause a form of dementia that may be mistaken for Alzheimer’s disease, while an insufficient intake of vitamin B6 may impair the function of your immune system.

Recommendations for Intake of B Vitamins

Get plenty of folic acid everyday. The RDA for this vitamin is 400 micrograms (mcg). Good sources include enriched breads and cereals, dried peas and beans, oranges, orange juice, green vegetables, and whole grains.

Eat foods rich in vitamin B6. The RDA for vitamin B6 is 1.5 mg for women over age 50 and 1.7 mg for men over age 50 (for adults age 19–50, the RDA is 1.3 mg). Good sources of vitamin B6 include fish, meats, poultry, avocados, and bananas.

Maintain an adequate vitamin B12 intake. The RDA for adults is 2.4 mcg per day. You can meet the RDA mainly by consuming foods with added B12 (such as fortified cereals) or taking a supplement containing B12. Choose a supplement that contains B12 in crystalline form (look for the word “cyanocobalamin” on the label), as it is better absorbed by people over age 50 than other B12 formulations. Vegetarians who eat no animal products (B12 is found in meat, poultry, shellfish, fish, eggs, and dairy products) need to take vitamin B12 supplements; people taking folic acid supplements should also take 1mcg of vitamin B12 daily.

Consult your doctor about whether to take B vitamins in individual supplements or as part of a multivitamin-mineral supplement. Most multivitamin-mineral supplements contain the amounts of folic acid, vitamin B6, and vitamin B12 recommended above.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Benefits of Vitamin B and Folic Acid

How To Lose Weight And Keep It Off

Wed, 10 Jan 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Lose Weight And Keep It Off

Six weight loss lessons from the National Weight Control Registry

Who better to glean weight loss tips from than people who’ve successfully lost weight and not put it back on? That’s the idea behind the National Weight Control Registry, a database of about 4,500 men and women who have maintained a 30 lb. or greater weight loss for at least a year. (In fact, the average member of the registry has lost around 60 lbs. and kept the weight off for 5 years.)

The registry, established in 1993, is the brainchild of James O. Hill, Ph.D., of the University of Colorado, and Rena Wing, Ph.D., of Brown University and the University of Pittsburgh. The duo are studying the experiences of successful dieters to determine the keys to weight loss success.

In the 10-plus years that Drs. Hill and Wing have been studying registry members, they’ve learned the following lessons about weight loss:

Weight Loss Lesson 1: You have to make a commitment to permanently alter your weight, so it’s important to make lifestyle changes you can live with over the long term. To lose weight and maintain their losses, the registry members had to make substantial changes in both their eating and exercise habits. They all had relied on diet and exercise strategies to help them lose weight (although some underwent weight loss surgery) and all were continuing to use diet and exercise to maintain their weight loss. Currently, most report a daily routine of eating about 1,800 calories and exercising for an hour (expending at least 374 calories).

Weight Loss Lesson 2: You can overcome your personal and family history of obesity. Two thirds of the registry members were overweight as children, and over half come from families with obese members.

Weight Loss Lesson 3: You don’t need to join a commercial weight-loss program or a gym to succeed in your weight loss goals. About half of the registry participants lost weight without the help of any formal programs. They used a variety of diets and strategies that best suited them individually. What that means is you have to find the ideal diet and exercise regimen for you. Some people like the freedom of going it alone; others prefer the structure of a commercial diet program, an exercise class, or a support group.

Weight Loss Lesson 4: You need to pay attention to your diet on a daily basis to maintain weight loss. Many people slip back into their old habits after losing weight or allow themselves short-term binges. But the registry participants show that it’s better to keep to a regular eating plan than to repeatedly splurge and diet. Participants who ate the same amount of food throughout the week or year were more likely to maintain their weight within a 5-lb. range than those who dieted more strictly on weekdays and non-holiday times.

Weight Loss Lesson 5: The longer you maintain weight loss, the easier it becomes. Registry members who had controlled their weight for the longest periods of time reported that it took less effort to stay on a diet and maintain their weight than it had when they were initially trying to lose weight and maintain their loss. This suggests that their new dietary and exercise regimens had become accepted habits and an integral part of their lifestyles.

Weight Loss Lesson 6: You don’t have to become an exercise fanatic to lose and maintain weight loss. The most common exercise reported by the registry members was plain old walking, which doesn’t require a gym membership or special equipment and can be done anywhere by almost everyone.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Lose Weight And Keep It Off

New Findings on Folic Acid and Fish Oil Supplements

Fri, 10 Nov 2006 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Folic Acid and Fish Oil Supplements

Folic Acid Reduces High Blood Pressure Risk in Women

Getting enough of the B vitamin folic acid is not only good for women looking to prevent birth defects in their future children, but folic acid may also protect them against high blood pressure, according to a 2005 study in the Journal of the American Medical Association.

Researchers reviewed data on folic acid intake from two large studies of women: The Nurses’ Health Study II, of 93,803 younger women age 27–44, and the Nurses’ Health Study I, of 62,260 older women age 43–70.

The younger women in the Nurses’ Health Study II who consumed at least 1,000 micrograms (mcg) of folic acid daily from their diet and supplements had a 46% reduction in their risk of developing high blood pressure compared with women who consumed less than 200 mcg of folic acid a day. Older women in the Nurses’ Health Study I also had a decreased risk, although it was less than that observed in the younger women. Until more studies confirm this finding, we do not recommend that you increase your daily folic acid to 1,000 mcg, especially by the use of folic acid supplements. The current recommended daily allowance for folic acid is 400 mcg, and this is a good amount of folic acid to aim for. If you decide to take a folic acid supplement, ask your doctor to check your B12 levels, since very high doses of folic acid can be dangerous if you have a B12 deficiency.

Fish Oil Supplements Can Worsen Heart Arrhythmias

The American Heart Association recommends oily fish or fish oil supplements to prevent potentially fatal heart arrhythmias (irregular heart rhythms) in people with coronary heart disease. So doctors were surprised to find in a recent study that fish oil supplements actually increased the risk of fatal heart arrhythmias in people with an implanted defibrillator who had a history of ventricular arrhythmias.

Two hundred patients with ventricular arrhythmias who required an implanted defibrillator (a device that shocks the heart back into a normal rhythm when it goes off beat) were given either 1.8 g of fish oil supplements a day or an olive oil placebo and followed for two years. Forty-six percent of the patients randomized to receive fish oil supplements experienced arrhythmias in the first six months of the study, compared with 36% of those receiving the placebo.

Patients with a history of ventricular arrhythmias were most at risk for fish oil-induced irregular heart rhythms. We recommend that you avoid fish oil supplements if you have an implanted defibrillator and recurrent ventricular arrhythmias, since the fish oil supplements could worsen your condition. Otherwise, discuss with your doctor whether taking a fish oil supplement might reduce your risk of sudden death from coronary heart disease.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Folic Acid and Fish Oil Supplements

Going Organic -- What Does the USDA Certified Organic Seal Really Guarantee?

Wed, 31 Jan 2007 06:00:00 CST

Johns Hopkins Health Alerts | Nutrition and Weight Control | Definition of Organic Food

Are organic foods really safer and more nutritious? Before you spend the extra money, read this Health Alert.

More Americans are turning to organic foods out of a concern for the environment as well as a desire to minimize exposure to certain chemicals in food. As a result, the market for organic foods is thriving. Over the past decade, consumer demand for organic foods in the United States has increased 20% or more each year. The Food Marketing Institute estimates that approximately 40% of all U.S. shoppers have purchased at least one organic food product. A diverse array of organic goods—from produce to frozen organic foods—is readily available to consumers, and the popularity of organic foods is expected to continue.

A national definition of the term “organic” was established in 2002 by the federal government. This definition encompasses a set of standards that governs the production, labeling, and marketing of organic foods. To be called organic, a food must be produced without the use of bioengineered foods, herbicides, irradiation, pesticides, synthetic fertilizers, or sewage sludge. Organic livestock must be raised on 100% organic feed, and antibiotics and growth hormones are prohibited. To find out if a food is organic, check the label for a “USDA Certified Organic” seal. (USDA stands for U.S. Department of Agriculture.)

While all organic foods carry this basic seal of approval, other words on the label indicate the quantity of organic ingredients the food contains:

“100% organic” means the food contains only organically produced raw or processed ingredients, with the exception of water and salt.

“Organic” indicates that 95% of the ingredients are organically produced.

“Made with organic ingredients” denotes that at least 70% of the ingredients in the product are organic.

For more information on organic food labels and regulations, visit www.ams.usda.gov/nop (the USDA’s National Organic Program website).

Currently, there is no scientific evidence that organic foods are safer, better in quality, or more nutritious than conventional foods. Additionally, although many people perceive organic foods as healthier than conventional foods, a USDA Certified Organic seal does not signify freshness, enhanced taste, or superior quality or nutritional content. Nor does organic guarantee that a food is pesticide free: Up to 5% pesticide residues are permitted in organic foods.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Definition of Organic Food

Sleep Deprivation -- A Link to Obesity?

Thu, 12 Oct 2006 14:02:51 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Obesity and Sleep Deprivation

One more reason to get a good night’s sleep: a recent study shows that people who sleep the least weigh the most!

Unfortunately, more and more Americans suffer from chronic sleep deprivation, with over one third of American adults now sleeping less than seven hours each night. Getting less than the recommended seven to nine hours of sleep a night can lead to poor concentration, raise the risk of colds and other infections, and leave you feeling worn out and easily irritated. Now new research has uncovered an association between chronic sleep deprivation and obesity. Whether sleeping more can help protect people against weight gain and obesity, however, is not yet clear.

Does less sleep=more weight?

Obesity rates have risen sharply in the United States in the last 20 years. This increase in obesity is a cause for concern because being overweight contributes to many medical disorders, including diabetes, cardiovascular disease, high blood pressure, stroke, cancer, and osteoarthritis. The rising tide of obesity has been attributed to poor eating habits, the wide availability of high-fat foods, watching too much television, and a sharp decline in physical activity. Several recent studies have raised the question of whether sleep deprivation should be added to this list.

In a study involving 924 participants between the ages of 18 and 91, reported in the Archives of Internal Medicine, researchers found that people who slept the least weighed the most. Another recent study analyzed data on about 18,000 adults who participated in the National Health and Nutrition Examination Survey. Compared with people who got seven to nine hours of rest each night, people who regularly slept less than four hours nightly were 73% more likely to suffer from obesity. One hypothesis is that shorter sleep duration is linked with imbalances in two hormones, leptin and ghrelin. Leptin is produced by fat cells and tells the brain when to stop eating, while ghrelin, which is produced by the stomach, triggers hunger. Leptin levels decline while ghrelin levels rise in people who are not getting enough sleep. But no studies thus far have suggested that how much you sleep has a direct impact on whether you lose or gain weight.

The bottom line on the link between obesity and sleep deprivation

“The association between inadequate sleep and obesity is undeniable, but whether there is a cause-and-effect relationship is dubious,” observes Lawrence J. Cheskin, M.D., Director of the Johns Hopkins Weight Management Center. Sleep deprivation may be the consequence, rather than the cause, of obesity. Sleep apnea, for example, may be a potential confounding factor because it is more common among people who are obese and can itself lead to poor sleep and sleep deprivation.

Certainly, no one recommends increasing your sleep time as a way to reduce your risk of obesity—at least not yet. But Lora Wilder, Sc.D, R.D., an Assistant Professor of Medicine at Johns Hopkins, notes, “It's reasonable to assume that getting good, regular sleep may help people eat more regular meals, which are associated with better weight control, and thus avoid eating as a ‘pick-me-up’ when what's really needed is sleep.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Obesity and Sleep Deprivation

The Promise of Pomegranates

Wed, 06 Sep 2006 06:00:00 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Antioxidants in Pomegranate Juice

They’re delicious and full of heart-healthy antioxidants -- should you add pomegranates to your diet?

The pomegranate, a rosy-red fruit containing glistening red seeds surrounded by pulp, is harvested in the autumn and is now starting to appear in produce sections. An ancient fruit native to the Middle East, the pomegranate has long been valued for its supposed medicinal properties. Recently, scientists have begun gathering evidence to support some of these claims. Recent laboratory studies suggest that powerful antioxidants called polyphenols in pomegranate juice can reduce the progression of atherosclerosis in the coronary arteries by inhibiting the oxidation of LDL cholesterol. The pomegranate juice also appears to stimulate the production of nitric oxide, a chemical that helps blood vessels relax.

If you are considering adding pomegranate juice or the fruit itself to your diet (remember, only the small juice sacs holding the fruit’s seeds are edible), there are a few things to keep in mind. Thus far, most data supporting the pomegranate’s potential health benefits come from laboratory studies and cannot be readily extrapolated to humans. In addition, several large clinical trials failed to show that antioxidants can prevent heart attacks or other major cardiovascular events -- so recent findings need to be kept in perspective.

Another factor to bear in mind is the added calories. Some experts estimate that you would have to drink about 16 oz., or 2 large glasses, of pomegranate juice daily to obtain significant cardiovascular benefits – that’s about 280 calories. Also, consider cost. A 16-oz. bottle of pomegranate juice costs at least $3.30. Finally, another recent study found that pomegranate juice inhibits an enzyme that may alter the metabolism of certain drugs, but more research is needed to determine the implications of these findings for humans. Still, pomegranates are a good source of potassium and vitamin C, and you may want to consider incorporating either the fruit or the juice into your 2 to 4 daily servings of fruit.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Antioxidants in Pomegranate Juice

The Obesity-Cancer Connection

Wed, 12 Jul 2006 13:44:18 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Obesity-Cancer Connection

More than 90,000 cancer deaths a year could be prevented if American adults maintained a healthy weight.

An impressive amount of scientific evidence has established obesity -- defined as a body mass index (BMI) of 30 or more -- as a risk factor for developing various types of cancer. Obesity also increases the risk of dying of cancer, even for those forms of cancer for which obesity is not already an established risk factor. A study by the American Cancer Society provides new evidence for this connection: As many as one in five cancer deaths each year among adults age 50 and over in the United States can be directly attributed to excess body weight. The message for Americans? Thousands of cancer deaths could be prevented if people lost weight.

Obesity and Cancer Risk

Obesity is a known risk factor for cancers of the breast, colon and rectum, endometrium (lining of the uterus), esophagus, and kidney.

Breast Cancer. The most common cancer in women, breast cancer is linked to obesity in post-menopausal women. Reseachers estimate that obese women have a 50% greater chance than nonobese women of developing breast cancer after menopause.

Colon and Rectal Cancer. The third leading cancer in men and women, colon and rectal cancer has been associated with several unhealthy aspects of the Western diet. However, obesity is the only recognized diet-related risk factor. Studies suggest that obesity doubles the risk of colorectal cancer in men and in premenopausal women.

Endometrial Cancer. The fourth most common cancer in women, endometrial cancer is linked to obesity in both premenopausal and postmenopausal women. Researchers estimate that obese women are three times more likely to develop endometrial cancer than women who are not obese.

Esophageal Cancer. Obesity is a known risk factor for developing a particular form of esophageal cancer, called adenocarcinoma, which arises from chronic damage to the lower esophagus.

Kidney Cancer. Although little information is available regarding the relationship between diet and kidney cancer, obesity has been identified as a risk factor. Obesity is thought to play a role in the development of one third of all kidney cancers in the United States.

Johns Hopkins Health Alerts | Nutrition and Weight Control | The Obesity-Cancer Connection

Eating Fish May Help Preserve Your Memory (Along With Your Heart) and Protect Against Alzheimer's Disease

Tue, 13 Jun 2006 14:09:24 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Omega-3 Protects Alzheimer’s Disease

In a recent study those who ate fish twice weekly reduced their risk of developing Alzheimer’s disease by 70%

Omega-3 fatty acids, which are abundant in fish, are known to play a role in protecting the heart. But now another benefit of these polyunsaturated fatty acids has turned up: People who consume omega-3 fatty acids also have a reduced risk of developing Alzheimer’s disease, according to a study in the Archives of Neurology.

Among 815 older Chicago residents without dementia, those who consumed fish once a week were 60% less likely to develop Alzheimer’s disease after four years than people who rarely or never ate fish. For those who ate fish twice weekly, the risk of developing Alzheimer’s disease was reduced by 70%.

Fish is a rich source of two types of omega-3s: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Another omega-3, alpha linolenic acid (ALA), is found mainly in plant oils and nuts, particularly canola, soybean, and flaxseed oils, as well as walnuts.

In the study, the participants completed dietary questionnaires, and the investigators calculated how much of the three omega-3s each person consumed. Most of the protective effect of omega-3s was from DHA. EPA had no significant effect, and ALA reduced the Alzheimer’s disease risk only in people with a genetic predisposition for Alzheimer’s disease.

As in all epidemiological studies, the benefit demonstrated here needs confirmation. But these results support the recommendation for regular inclusion of omega-3–rich foods in the diet.

So-called fatty fish such as herring, sardines, salmon, mackerel, trout, halibut, and tuna contain more omega-3 fatty acids than “lean” species such as cod or haddock. Although more research is needed to establish recommended daily intake values, the American Heart Association suggests eating at least two 3-ounce servings of seafood (preferably fatty species) weekly to gain a cardioprotective effect.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Omega-3 Protects Alzheimer’s Disease

Weight Loss Through Liposuction: No Real Health Benefits (But Some Real Risks)

Fri, 11 Aug 2006 14:05:50 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Liposuction for Weight Loss

Liposuction is appropriate only for people of normal or near-normal weight who have stubborn fat deposits that do not respond to diet and exercise.

While the surgical removal of fat may seem like an ideal method of weight reduction, liposuction is, at best, a questionable solution.

Unlike diet and exercise, fat reduction via liposuction has no proven health benefits. In fact, in a study published in The New England Journal of Medicine, researchers investigated the effects of large-volume liposuction—removal of about 20 lbs. of fat—on 15 obese women, including 8 with type 2 diabetes. After a 10- to 12-week recovery period, the women were an average of 9 to 11 lbs. lighter than before liposuction and had reductions in body mass index and waist circumference. Yet no improvements were seen in insulin sensitivity, blood pressure, blood glucose, insulin, lipid concentrations, and blood markers of inflammation and insulin resistance. A similar degree of weight loss by conventional means typically improves all of these values.

Liposuction also cannot help those who are diffusely overweight. Instead, the liposuction is appropriate only for people of normal or near-normal weight who have stubborn fat deposits that do not respond to diet and exercise. Candidates should also be in good general health and have skin that is elastic enough to shrink evenly after the liposuction surgery—which rules out many people over 50. Finally, liposuction comes with no cosmetic guarantees: While the extracted fat cells will not return, weight can still be gained at other sites in the body.

Common sites of liposuction include the abdomen, hips, buttocks, thighs, legs, upper arms, face, and neck; sometimes several areas are treated at once. Patients must wear a special pressure dressing (such as a girdle or body stocking) over the treated area for several weeks after liposuction to help the skin shrink to fit the new contour and to minimize bruising and swelling (which may persist for months).

While the overall risk associated with liposuction is low, the more fat that is removed, the greater the risk of complications such as infection or blood clots. Patients interested in liposuction should consult their doctor for an assessment and, possibly, a referral to an experienced plastic surgeon.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Liposuction for Weight Loss

Using BMI And Waist Circumference To Assess Healthy Weight

Mon, 17 Apr 2006 13:37:41 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | BMI and Obesity

While BMI (body mass index) is a general assessment of body weight and disease risk, waist circumference provides a more specific measure of health risk because waist circumference indicates harmful abdominal fat.

Height|weight tables are the most straightforward way to assess your weight, but there are drawbacks to relying solely on this method. The tables are not based on scientific calculations of ideal weight but instead are derived from height, weight, and mortality data of people seeking life insurance. Moreover, they do not take into account body composition.

As the result of the difficulty in directly measuring the amount of body fat and the drawbacks of using height|weight tables alone, researchers have turned to a measurement called BMI to define obesity and its severity. BMI is a measurement of your weight as it relates to your height. BMI correlates strongly with the amount of body fat, though it does not measure it directly.

Federal guidelines define overweight as a BMI from 25 to 29.9 and obesity as a BMI of 30 or greater. Morbid obesity is a BMI of 40 or greater. To calculate your BMI, multiply your weight (in pounds) by 703; divide the result by the square of your height (in inches).

While BMI is a general assessment of body weight and disease risk, waist circumference provides an added and more specific measure of health risk because waist circumference indicates harmful abdominal fat. Research shows that the mortality rates and incidence of certain chronic diseases, such as diabetes and high blood pressure, are substantially higher in those with a disproportionate amount of body fat stored in the abdomen.

Fortunately, abdominal fat is often the first to go with weight loss. Typically, men are prone to fat deposition in the abdomen—developing what is commonly called a pot belly, beer belly, or apple shape—whereas women tend to accumulate fat around the hips, buttocks, and thighs, a distribution called a pear shape. However, women are not immune to accumulating abdominal fat, and weight tends to be stored in a pattern typical to a particular individual (in other words, once a pear, always a pear).

Even in people of normal weight, an increased waist circumference may be linked to an elevated health risk. (A normal waist circumference is less than 40 inches in men and less than 35 inches in women.) And in men and women who are overweight or obese, a large waist circumference increases the already elevated risk of disease. But people with a BMI of 35 or higher have a high risk of disease, regardless of their waist circumference.

Johns Hopkins Health Alerts | Nutrition and Weight Control | BMI and Obesity

Fending Off Heart Disease With Fiber

Fri, 14 Apr 2006 21:32:43 CDT

Johns Hopkins Health Alerts | Nutrition and Weight Control | Fending Off Heart Disease With Fiber

Studies suggest that an increase of 5 to 10 g per day in soluble fiber intake—two to four extra servings of fruits and vegetables—reduces cholesterol levels by about 5%.

For many years, fiber (the indigestible component of plant foods) was thought to be useful only for adding bulk to the diet to prevent constipation. But the shift in the diets of Western societies from ones based on whole grains, vegetables, fruits, and legumes to diets based on meats, refined grains, and processed foods has been associated with an increase in the incidence of coronary heart disease as well as diabetes; several studies point to a lack of dietary fiber as a primary cause. Some debate has ensued over whether fiber has a protective effect or is simply a marker for a healthy diet. But in recent studies, fiber has emerged as an independent factor for the prevention of disease.

Both types of fiber—soluble (sometimes called viscous) fiber, which dissolves in water and forms a gel-like substance, and insoluble fiber, which does not dissolve in water—are important for disease prevention. Most plant foods contain some of each type, but often one or the other predominates. Soluble fiber is found in legumes, barley, oats, and most fruits, while wheat and other whole grains and some vegetables contain insoluble fiber.

The two types of fiber exert different effects in the intestine. Soluble fiber binds bile acids and removes them in the stools. By absorbing many times its weight in water, insoluble fiber increases stool bulk and helps wastes pass more easily and rapidly through the digestive tract.

The connection between fiber and heart disease has focused on the effect of soluble fiber on blood cholesterol levels. In the liver, cholesterol is used to make bile acids. Soluble fiber binds with bile acids in the intestines and removes them in the stool. The liver responds by converting more cholesterol into bile acids. The resulting fall in cholesterol in liver cells leads them to take up more LDL (“bad”) cholesterol from the blood.

Studies suggest that an increase of 5 to 10 g per day in soluble fiber intake—two to four extra servings of fruits and vegetables—reduces cholesterol levels by about 5%. Other studies have shown that fiber intake directly affects the risk of fatal and nonfatal heart attacks.

Other research indicates that soluble fiber is more strongly associated with a reduced risk of heart attack and heart disease death than insoluble fiber. However, the effect of soluble fiber on blood cholesterol levels does not fully account for the protective effect of dietary fiber. This finding opens the possibility that fiber may work in additional ways—by affecting the body’s use of glucose and insulin, for example, or by reducing triglyceride levels.

Johns Hopkins Health Alerts | Nutrition and Weight Control | Fending Off Heart Disease With Fiber