Nutritional Management of Type 2 Diabetes Mellitus and Obesity and Pharmacologic Therapies to Facilitate Weight Loss

Diet plays an integral role in the treatment of type 2 diabetes mellitus (T2DM). Unfortunately, many patients with T2DM do not have access to a registered dietitian or certified diabetes educator, and rates of physician counseling about diet remain low. This article provides an overview of the current recommendations for the nutritional management of T2DM, which are endorsed by the American Diabetes Association (ADA). Medical nutrition therapy, which provides a flexible and individualized approach to diet, emphasizes the total number (rather than the type) of carbohydrate consumed. Because fat intake also affects glycemia and cardiovascular risk, a reduction in daily mono- and polyunsaturated fat intake is recommended for most patients with T2DM. Weight loss plays an important adjunct role in treating patients with T2DM, because the majority of individuals with T2DM are overweight or obese. Patient lifestyle modification, which encompasses diet, physical activity, and behavioral therapy, can be used to facilitate weight loss in conjunction with several different dietary approaches. These include low-carbohydrate, low-fat, low-glycemic index, and Mediterranean diets. Studies have demonstrated that modest weight loss (5%-10% of body weight) is associated with significant improvements in patient measures of glycemic control, lipids, blood pressure, and other cardiovascular risk factors. Furthermore, a modest weight loss of as little as 4.5 kg can result in reducing the glycated hemoglobin level by approximately 0.5%. Pharmacologic agents, when combined with these approaches, may further augment weight loss. Familiarity with these principles can help physicians provide dietary counseling to their patients with T2DM and obesity.