The postprandial effects of macronutrient composition on appetite response in normal-weight and obese men: a pilot randomized crossover clinical trial

Controlling appetite during the postprandial phase is proposed to be an effective strategy for preventing and managing obesity, therefore, considering the conflicting results of previous studies, we aimed, in this pilot study, to explore the feasibility of assessing postprandial appetite responses to meals with different macronutrient compositions in both normal-weight and obese men. In this randomized crossover clinical trial, two groups of obese ( n = 10) and normal-weight ( n = 10) men received each test meal, which included high protein (30%), high carbohydrates (70%), or high fat (50%) content, on three separate days with a 7—to 10-day washout period. The visual analog scale was completed before and seven times after consuming the meal to evaluate appetite. SPSS software version 22 was utilized. The mean age of participants was 25.75 ± 3.78 years. A significant difference in the hunger trend was observed between the intervention groups ( P < 0.005). Although the mean score of hunger sensation was lower in the high-protein group than the high-fat and carbohydrate groups, a statistically significant difference was found only between the high-protein and fat groups ( P < 0.001). The protein-rich group reported feeling fuller than the other groups. A statistically significant difference among groups was noted ( P < 0.002). In this context, the differences between high-protein and fat groups ( P < 0.001) and between high-protein and carbohydrate groups ( P < 0.025) were significant. No significant differences were observed in appetite changes between the obese and normal-weight groups in any of the intervention groups. This study’s findings suggest that a high-protein meal is more effective than high-carbohydrate or high-fat meals in reducing hunger and enhancing satiety during the postprandial phase. Additionally, there were no significant differences in appetite changes between obese and normal-weight men. This research was approved by the ethics committee of Mashhad University of Medical Sciences (IR.MUMS.MEDICAL.REC.1398.185) and registered in IRCT (Code: IRCT201908180445528; registered on August 26, 2019, the direct access link to the resource: https://www.irct.ir/trial/41583 ).