Critical review of the international guidelines: what is agreed upon--what is not?

The nutrition recommendations of 6 major scientific organizations (the American Diabetes Association, the Diabetes and Nutrition Study Group of the European Association for the Study of Diabetes, the Canadian Diabetes Association, the Joslin Diabetes Center and Joslin Clinic, the American Association of Clinical Endocrinologists and Diabetes UK) are reviewed. They all agree that weight loss (with reduction in energy intake and increase in physical activity) is an important therapeutic strategy in all overweight/obese individuals who have or are at risk of type-2 diabetes. Very low carbohydrate diets are not considered appropriate. The recommended proportion varies slightly (from 40 to 65%). The concept of the glycemic index is stressed as important in nearly all guidelines. Fiber intake is advised, up to 50 g/day, if tolerated. Protein intake (for normal kidney function) is advised to range from 10 to 20% of total energy. A low fat diet (<30-35%) is recommended by all. Saturated fat and trans-fatty acids should be restricted to <10% and dietary cholesterol to <300 mg/day. Monounsaturated fatty acids are generally considered beneficial and should replace saturated fat or carbohydrates in low-fat diets. Polyunsaturated fatty acids (PUFAs) should comprise about 10%, with the n-3 PUFAs being more beneficial, especially for high triglyceride levels. Alcohol intake has cardioprotective effects when used in moderation. Routine supplementation of the diet with antioxidants and vitamins is not necessary.