The effects of acute exercise on appetite and energy intake in men and women

Purpose: To compare energy intake (EI) and appetite regulation responses between men and women following acute bouts of aerobic (AEx), resistance exercise (REx), and a sedentary control (CON). Methods: Men and women (n = 24; 50% male) 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 3 conditions: 1) AEx (65-70% of age-predicted maximum heart rate for 45 min); 2) REx (1-set to failure on 12 exercises); and 3) CON. Each condition was initiated in the post-prandial state (35 min following consumption of a standardized breakfast). Appetite (visual analog scale for hunger, satiety, and prospective food consumption [PFC]) and hormones (ghrelin, PYY, and GLP-1) were measured in the fasted state and every 30 min post-prandially for 3 h. Postexercise ad libitum EI at the lunch meal was also measured. Results: Men reported higher levels of hunger compared to women across all study conditions (AEx: Men: 7815.00 +/- 368.3; Women: 5428.50 +/- 440.0 mm x 180 min; p = 0.025; REx: Men: 7110.00 +/- 548.4; Women: 6086.25 +/- 482.9 mm x 180 min; p = 0.427; CON: Men: 8315.00 +/- 429.8; Women: 5311.25 +/- 543.1 mm x 180 min; p = 0.021) and consumed a greater absolute caloric load than women at the ad libitum lunch meal (AEx: Men: 1021.6 +/- 105.4; Women: 851.7 +/- 70.5 kcals; p = 0.20; REx: Men: 1114.7 +/- 104.0; Women: 867.7 +/- 76.4 kcals; p = 0.07; CON: Men: 1087.0 +/- 98.8; Women: 800.5 +/- 102.3 kcals; p = 0.06). However, when adjusted for relative energy needs, there was no difference in relative ad libitum EI observed between men and women. No differences in Area Under the Curve for Satiety, PFC, ghrelin, PYY, and GLP-1 were noted between men and women following acute exercise (all p > 0.05). Conclusions: These data suggest that women report lower ratings of appetite following an acute bout of exercise or sedentary time when compared to men, yet have similar relative EI. Future work is needed to examine whether sex-based differences in appetite regulation and EI are present with chronic exercise of differing modalities.