The satiating effect of egg is higher than fresh cheese when given as isocaloric "solid" preloads in humans

Proteins are usually considered to have a specific satiating effect but the differences between different protein sources are unclear. The objective was to compare the satiating effect of two isocaloric "solid" preloads containing egg or milk protein (omelette or fresh cheese), and to relate this effect to plasma metabolites and hormones variations. 30 subjects participated to 2 randomised test days, one per preload. On each test day, after consumption of the whole prelaod (322kcal; 26g proteins, 21g lipids, 7.5g lactose), their appetite sensations were recorded until they asked for the next meal. The delay between the preload and the next meal as well as the spontaneous energy intake at the meal were measured. In 10 volunteers, blood samples were taken during the same time in order to measure plasma concentrations of energy metabolites and satiety hormones. The two products displayed no difference for the delay between the preload and the meal, but the omelette reduced significantly the energy intake at the meal by 300 kcal in comparison to the fresh cheese. Subjects reported to feel less hunger with the omelette. GIP and insulin secretions and uremia increased significantly after the fresh cheese but not the omelette, while glucagon and GLP-1 secretions displayed delayed profiles with the omelette. We conclude that eggs present a more satiating effect than a fresh dairy product on the basis of a decreased energy intake. Uremia and hormone profiles suggest that this effect is mainly due to a slower digestion rate, caused by a different structure of the food.