Obesity in persons with diabetes is associated with poorer control of blood glucose levels, blood pressure, and cholesterol, placing persons with diabetes at higher risk for both cardiovascular and microvascular disease. Conversely, intentional weight loss is associated with reduced mortality among overweight persons with diabetes. CDC analyzed the prevalence of overweight and obesity among U.S. adults aged >/=20 years with previously diagnosed diabetes by using data from two surveys: the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994, and NHANES 1999-2002. This report summarizes the results of that analysis, which indicated that most adults with diagnosed diabetes were overweight or obese. During 1999-2002, the prevalence of overweight or obesity was 85.2%, and the prevalence of obesity was 54.8%. Encouraging patients to achieve and maintain a healthy weight should be a priority for all diabetes-care programs.