ZEIST, Netherlands--Protein is more satiating than carbohydrate, according to a study published in the American Journal of Clinical Nutrition (83, 2:211-20, 2006). In the single blind, crossover study, researchers administered an isocaloric high-protein breakfast (58.1 percent of energy from protein and 14.1 percent of energy from carbohydrate) or high-carbohydrate breakfast (19.3 percent of energy from protein and 47.3 percent of energy from carbohydrate) to15 healthy men. Blood samples and subjective measures of satiety were assessed frequently for three hours after consumption. The high-protein breakfast decreased secretion of postprandial ghrelin (a hormone that stimulates hunger) more than did the high-carbohydrate breakfast. Appetite ratings were not significantly different between the two groups, and the high-protein breakfast did not significantly affect ad libitum energy intake. The researchers concluded the high-protein breakfast decreased postprandial ghrelin concentrations more strongly over time than did the high-carb breakfast, and noted high associations between ghrelin and glucose-dependent insulinotropic polypeptide and glucagon suggest stimulation of these peptides may mediate the postprandial ghrelin response. In addition, the high-protein breakfast also reduced gastric emptying, probably through increased secretion of cholecystokinin and glucagon-like peptide 1, the researchers said.