SATIETY AFTER PRELOADS WITH DIFFERENT AMOUNTS OF FAT AND CARBOHYDRATE- IMPLICATIONS FOR OBESITY

High intake of dietary fat may be key in both the etiology and mainten ance of obesity. Because a reduction in the proportion of energy deriv ed from fat will be accompanied by an increase in the proportion of en ergy derived from carbohydrate, this study compared the effects of the se macronutrients on eating behavior in obese and lean individuals. Th e effects of different amounts of fat and carbohydrate, covertly incor porated into yogurt preloads, on subsequent food intake, hunger, and s atiety were assessed. A group of 12 normal-weight men, unconcerned abo ut eating and body weight (unrestrained), accurately compensated for t he energy in the preloads regardless of the nutrient composition. Othe r groups (n = 12 per group), including normal-weight restrained men an d normal-weight and obese restrained and unrestrained females, did not show such orderly energy compensation; joule-for-joule, the high-fat preloads suppressed intake at lunch less than did high-carbohydrate pr eloads. These results suggest that a relative insensitivity to the sat iating effect of fat could be involved in the development and maintena nce of obesity.