Background

The purpose of our ongoing trial is to determine how aerobic exercise (AEx) training influences appetite, gut peptides, food-related behaviors, and energy intake, and to understand differences between Compensators (those who gain or do not lose weight) vs Non-Compensators (those who lose weight).

Methods

Previously inactive, overweight/obese adults (n=24, 79% female, 36±2 yrs, BMI: 30.1±0.5 kg/m2) completed a 12-week AEx program. At baseline and post intervention, appetite (VAS for hunger and satiety) and hormones (ghrelin, PYY) were measured in the fasted state and every 30 minutes for 3 hours following breakfast. Dietary restraint, disinhibition, and hedonic hunger were measured via Three-Factor Eating Inventory. Food cravings were measured with the Food Craving Inventory in the fasted and postprandial state.Ad libitum energy intake was measured for 3-days using food provided by a metabolic kitchen.Baseline differences between Compensators (tertile with no weight loss to weight gain, n=8) vs Non-Compensators (tertile with greatest weight loss, n=8) were evaluated with independent samples t-test. Differences in response to AEx were evaluated with RM-ANOVA.

Results

At baseline, Non-Compensators (weight change: -4.7±0.5 kg, p<0.001) reported higher fasting and AUC for satiety (24±7 vs. 6±2, p=0.035 and 10,022±763 vs. 7,363±607, p=0.016, respectively), had lower hedonic hunger (2±0.4 vs. 5±1.0, p=0.042), and tended to be older (41±3 vs. 33±2 yrs, p=0.07) and have lower postprandial food cravings (27±3 vs. 35±3, p=0.085) than Compensators (weight change: +1.7±0.5 kg, p=0.012). In response to AEx, dietary restraint tended to increase more in Non-Compensators (+4±4 vs +1±1 p=0.090). No differences in appetite-related hormones nor ad libitum energy intake were detected between groups at baseline nor in response to 12 weeks of AEx.

Conclusions

Baseline food behaviors, cravings, and subjective appetite measures may be predictive of changes in body mass in response to exercise training.