Observational studies show that prevalence of type 2 diabetes is 1.6 to 2 times lower in vegetarians than in the general population, even after adjustment for differences in body mass index (BMI). Clinical interventional trials demonstrated that vegetarian diets lead to a greater weight loss and greater reduction in fasting plasma glucose, HbA1c, blood lipids, and hypoglycemic medication than a conventional hypocaloric diet in subjects with type 2 diabetes. We found a greater reduction in visceral fat and greater improvements in insulin resistance and oxidative stress markers with a vegetarian compared to a conventional hypocaloric diabetic diet. Vegetarian diets are sustainable in the long term and may elicit desirable improvements not only in physical health but also in mental health. The American Dietetic Association states that well-planned vegetarian diets are healthy and nutritionally adequate and they may be beneficial in prevention and treatment of some illnesses. Larger clinical trials are needed to confirm the effectiveness and promote the inclusion of vegetarian diets in dietary guidelines for prevention and treatment of type 2 diabetes.
Keywords: diet; prevention; treatment; type 2 diabetes; vegetarian.