Diabetes Mellitus Treatment Regimens - Diet

A. DIET

A well-balanced, nutritious diet remains a fundamental element of therapy. However, in more than half of cases, diabetic patients fail to follow their diet. In prescribing a diet, it is important to relate dietary objectives to the type of diabetes. In obese patients with mild hyperglycemia, the major goal of diet therapy is weight reduction by caloric restriction. Thus, there is less need for exchange lists, emphasis on timing of meals, or periodic snacks, all of which are so essential in the treatment of insulin-requiring nonobese diabetics. This type of patient represents the most frequent challenge for the clinician. Weight reduction is an elusive goal that can only be achieved by close supervision and education of the obese patient.

1. American Diabetes Association recommendations - The ADA releases an annual position statement on medical nutrition therapy that replaces the calculated ADA diet formula of the past with suggestions for an individually tailored dietary prescription based on metabolic, nutritional, and lifestyle requirements. They contend that the concept of one diet for "diabetes" and the prescription of an "ADA diet" no longer can apply to both major types of diabetes. In their recommendations for persons with type 2 diabetes, the 55-60% carbohydrate content of previous diets has been reduced considerably because of the tendency of high carbohydrate intake to cause hyperglycemia, hypertriglyceridemia, and a lowered HDL cholesterol. In obese type 2 patients, glucose and lipid goals join weight loss as the focus of therapy. These patients are advised to limit their carbohydrate content by substituting noncholesterologenic monounsaturated oils such as olive oil, rapeseed (canola) oil, or the oils in nuts and avocados.

This maneuver is also indicated in type 1 patients on intensive insulin regimens in whom near-normoglycemic control is less achievable on higher carbohydrate diets. They should be taught "carbohydrate counting" so they can administer 1 unit of regular insulin or short-acting insulin analog for each 10 or 15 g of carbohydrate eaten at a meal. In these patients, the ratio of carbohydrate to fat will vary among individuals in relation to their glycemic responses, insulin regimens, and exercise pattern.

The current recommendations for both types of diabetes continue to limit cholesterol to 300 mg daily and advise a daily protein intake of 10-20% of total calories. They suggest that saturated fat be no higher than 8-9% of total calories with a similar proportion of polyunsaturated fat and that the remainder of caloric needs be made up of an individualized ratio of monounsaturated fat and of carbohydrate containing 20-35 g of dietary fiber. Poultry, veal, and fish continue to be recommended as a substitute for red meats for keeping saturated fat content low. The present ADA position statement proffers no evidence that reducing protein intake below 10% of intake (about 0.8 g/kg/d) is of any benefit in patients with nephropathy and renal impairment, and doing so may be detrimental.