Eating high-fiber foods slows digestion and helps to prevent a rapid rise in blood sugar.
Efforts to prevent type 2 diabetes are especially important for people with known risk factors for developing the disease, such as those with prediabetes, obesity, a family history of diabetes, and a personal history of diabetes during pregnancy (gestational diabetes). The risk of diabetes is also elevated among blacks, Hispanics, Asians, and Native Americans. Carefully designed research studies in Finland, China, and the United States all show that modest weight loss and regular physical activity can help to prevent type 2 diabetes.
A high-fiber diet may also decrease the risk of developing type 2 diabetes by helping to prevent insulin resistance, according to a study reported in the journal Diabetes Care. Surprisingly, frequent consumption of high-sugar foods and foods with a high glycemic index (rapidly digested carbohydrates) did not increase the probability of insulin resistance, the researchers say.
The investigators studied the relationship between diet and insulin resistance in 5,675 people ages 30–60 years who had completed questionnaires that reported how often they consumed a wide variety of foods. None of the participants had diabetes. The results showed that diets with a high total carbohydrate content, including a high intake of simple sugars (sucrose and glucose) or a high total glycemic index, did not affect the probability of having insulin resistance. However, people with a high intake of dietary fiber did decrease insulin resistance.
The researchers note that many fruits and vegetables that are high in carbohydrates are also high in fiber. The fiber slows digestion and helps to prevent a rapid rise in blood sugar. This protective effect may explain the benefits of a high fiber diet, according to this report. These results support the current belief that increasing the intake of fiber-rich carbohydrates can help to prevent insulin resistance. Larger studies are needed to confirm the lack of effect of high-glycemic foods on insulin resistance risks, the authors say.
