Metabolic and Appetite Hormone Responses of Hyperinsulinemic Normoglycemic Males to Meals with Varied Macronutrient Compositions

Abstract

Aims: The aim of this study was to investigate the appetite hormones and metabolic responses of hyperinsulinemic subjects to high-protein (HP) meals as compared to high-carbohydrate (HC) and high-fat (HF) meals. Design: Fifteen hyperinsulinemic normoglycemic men received, on 3 separate occasions, HP, HC, or HF meals in a randomized crossover design. Blood samples were collected before and after the ingestion of each meal. Postprandially, acylated ghrelin, PYY_3–36, insulin, glucose, and triglycerides were measured. Results: While the HC meal induced an acutely greater postprandial ghrelin decrease below baseline, the HP meal maintained this decline significantly more than the HF meal at 240 min. Postprandial PYY_3–36 responses did not significantly vary with time and meal composition. Postprandial insulin and glucose peaks were significantly lower following the HP and HF meals in comparison to the HC meal, whereas triglyceride responses were significantly higher following the HF meal. Significant correlations, negative between acylated ghrelin and insulin and positive between PYY_3–36 and insulin, were observed. Conclusions: In hyperinsulinemic normoglycemic men, HP meals ensure a longer-lasting suppression of circulating ghrelin levels and result in more favorable metabolic responses, characterized by a lower surge of postprandial insulin and glucose and a reduced postprandial triglyceride response, as compared to both HC and HF meals.