Effects Of Acute Exercise On Appetite Regulation And Energy Intake In Men And Women

Abstract

PURPOSE: Compare energy intake and appetite regulation responses between men and women following acute bouts of aerobic (AEx) and resistance exercise (REx). METHODS: Men and women (n=12 each) with overweight/obesity matched on age (32.3±2 vs. 36.8±2 yrs, p=0.14) and BMI (28.1±1.2 vs 29.0±1.5 kg/m2, p=0.64) completed 2 conditions; 1) AEx (65-70% of age-predicted maximum heart rate for 45 min) and 2) REx (1-set to failure on 12 exercises). Each condition was initiated in the post-prandial state (35 minutes post breakfast). Appetite (visual analog scale for hunger, satiety and prospective food consumption [PFC]) and hormones (ghrelin, PYY, and GLP-1) were measured before and every 30 minutes for 3 hours following consumption of a standardized breakfast. Post exercise ad libitum energy intake at the lunch meal was also measured. RESULTS: There was no difference in relative ad libitum energy intake between men and women following either AEx (43.4±5 vs.45.4±4% of total energy needs, p=0.80) or REx (48.3±3 vs. 46.6±3% of total energy needs, p=0.81). In the AEx condition there were no differences in area under the curve (AUC) for satiety or PFC between men and women, although men reported higher PFC vs women at the 30 (33.3±5 vs. 17.5±4mm, respectively, p=0.03) and 90 min (49.8±6 mm vs 30.2±6 mm, respectively, p=0.03) post-prandial time points. Additionally, in the AEx condition, a greater hunger AUC was detected in men vs women (7815±638 vs 5428±762 mm, respectively, p=0.02), which was driven by men reporting significantly greater hunger vs women at the 90 min post-prandial time point (42.7±5 vs.16.6±4 mm, p<0.001). No differences in AUC for ghrelin, PYY, and GLP-1 were noted between men and women following either AEx or REx (all p>0.05). However, significantly higher ghrelin was observed in women vs. men at the 150 (807.6±37 vs. 652.2±41 pg/mL, respectively, p=0.01) and 180 min (812.4±39 vs. 677.5±49 pg/mL, respectively, p=.05) post-prandial time points. CONCLUSIONS: The data suggest that men report greater hunger and PFC than women following acute AEx, and that women have higher ghrelin levels than men following acute REx. Future work is needed to examine if sex-based differences in appetite regulation and energy intake are present with chronic exercise of differing modalities.