Optimal macronutrient distribution of weight loss diets has not been established. The Institute of Medicine (24), American Diabetes Association (3), and American Heart Association (AHA) (25) recommend the following spectrum of dietary composition for the general adult population: 20–35% of energy (AHA 25–35%) from fat; 45–65% of energy (AHA 50–60%) fromcarbohydrates; and 10–35% of energy (at least 0.8 g/kg) from protein.