The Atkins Diet, South Beach Diet and others like them maintain that low-carbohydrate diets offer a metabolic advantage over low-fat diets by burning more calories for energy. The weight loss seen with these diets is more the result of high protein than low carb, according to the University of WI, Madison. In fact, a recent review of studies that they authored found some evidence of a very slight metabolic advantage for high-protein diets. Protein increases satiety, helping dieters stick to low-calorie diets. And protein may slightly blunt the fall in resting metabolism that occurs with weight loss. Still, what matters most is calories. The vast majority of weight loss is explained by how much people cut calories and how much they exercise, not by changing the percentage of carbohydrates, protein or fat in their diets.