The Quantity of Meal Fat Influences the Profile of Postprandial Hormones as Well as Hunger Sensation in Healthy Elderly People

BACKGROUND: In healthy elderly people, reduced appetite and the consequent decrease in food intake has been defined as the "anorexia of aging"; this condition may lead to malnutrition. The aim of this study was to investigate how different compositions of macronutrients affect satiety and hunger signals as well as subjective sensations after meals in healthy elderly subjects. METHODS: Experimental controlled study. Ambulatory healthy community-dwelling subjects evaluation in a single center on 12 elderly subjects, (75.2+/-2 years old) and 12 younger controls (28.2+/-2 years old). Using a visual analogical scale, hunger was evaluated under fasting conditions and at 30-minute intervals for up to 4 hours after two 800-kcal meals, where 20% and 40% of the calories were derived from fat. Serum samples were collected at -30, 60, 120, and 240 minutes to determine the concentrations of GLP-1, acylated and desacylated ghrelin, triglycerides, glucose, and insulin. RESULTS:Serum concentrations of GLP-1 were higher after the 40% fat meal than after the 20% fat meal (P < .01) in the elderly but not in the younger subjects. Acylated to desacylated ratio was lower after the 40% fat meal (P < .05) in the elderly. Only in the older group were triglycerides higher (P < .05), whereas hunger was significantly lower (P < .05) after the 40% fat meal. CONCLUSION: In healthy elderly people relatively large amounts of fat increase the satiety signal from GLP-1 and lower the acylated to desacylated ratio of ghrelin, consequently decreasing hunger. This condition may lead to a reduction in calorie intake.