Carbohydrates, appetite and feeding behavior in humans

The view of carbohydrates in relation to obesity has changed over the past few decades from being conducive to overconsumption and weight gain to bein g protective. This article reviews the mechanisms by which carbohydrate is purported to protect against weight gain. Although carbohydrate is metaboli zed and stored in the body less efficiently than fat, when de novo lipogene sis is invoked on very high carbohydrate diets, the beneficial effect on en ergy balance is likely to be minimal when typical high fat Western diets ar e consumed. However, it has been suggested that high carbohydrate foods may influence energy balance by reducing food intake through greater satiety e ffects, reducing energy density and displacing fat from the diet-the fat-su gar seesaw effect. To date, there seem to be few differences between sugars and starches on satiety and energy intake, but few studies have examined t his. Some reduced-fat, and, therefore, higher carbohydrate, foods are highl y energy dense. High carbohydrate foods do not necessarily have a low energ y density. Evidence from recent studies suggests that adding carbohydrate, and especially sugar, to the diet neither displaces fat from the diet nor p rotects against elevated energy intake. Although it is easier to overeat on high fat than low fat foods, simply replacing fat with carbohydrate in the diet may not be as protective against overconsumption as the energy densit y or fat-sugar seesaw arguments suggest.