['To emphasize the importance of medical nutrition therapy in the overall management of diabetes.', 'Published reports of the effectiveness of nutrition intervention in glycemic control are reviewed, and useful strategies for implementation of lifestyle changes in patients with diabetes are discussed.', 'In randomized controlled trials of nutrition therapy in patients with diabetes, reduction in hemoglobin A1c levels has been demonstrated. The focus of medical nutrition intervention in patients with diabetes should be strategies that will address the metabolic abnormalities of glucose, lipids, and blood pressure associated with this disease. Early referral for lifestyle changes and advice will yield the most benefit in prevention of development of type 2 diabetes or minimization of progression of the disease if the diagnosis has already been made. Patients should be educated about the progressive nature of type 2 diabetes and the importance of glycemic control, with appropriate food choices and physical activity in conjunction with their antidiabetes medication.'] Do diets fail : the success of medical nutrition therapy in patients with diabetes?