Research has shown that whey protein reduces hunger more than most. Whey is more filling because of its high levels of a peptide called glycomacropeptide (GMP), which is known to be a powerful satiety inducing nutrient. It works by stimulating the release of cholecystokinin (CCK), a hormone that’s responsible for controlling hunger. Whey protein also reduces hunger by lowering circulating levels of the hunger hormone ghrelin. A recent Australian study found that a whey protein drink produced a prolonged suppression of ghrelin compared to glucose and fructose beverages.  Yet another line of research suggests that whey promotes body fat loss by blocking fat storage. In one recent French study, lab animals were fed a normal diet, a high-protein diet, or a whey-enriched high-protein diet for 42 days. At the end of the study period, the animals fed the whey diet weighed 30 % less than those fed the normal diet and 17 % less than those fed the regular high-protein diet, yet the whey-fed animals had the highest levels of lean body mass of the three groups. The researchers attributed these results to reduced fat storage caused by the high concentrations of branched-chain amino acids in the whey.