Biological and behavioral predictors of compensatory energy intake after exercise

Energy intake in the post-exercise state is highly variable and compensatory eating – i.e., (over ‐ ) compensation of the expended energy via increased post-exercise energy intake – occurs in some individuals but not others. We aimed to identify predictors of post-exercise energy intake and compensation. In a randomized crossover design, 57 healthy participants (21.7 [SD=2.5] years; 23.7 [SD=2.3] kg/m 2 , 75% White, 54% female) completed two laboratory-based test-meals following (1) 45-min exercise and (2) 45-min rest (control). We assessed associations between biological (sex, body composition, appetite hormones) and behavioral (habitual exercise via prospective exercise log, appetitive traits) characteristics at baseline and total energy intake, compensatory energy intake (intake – exercise expenditure), and the difference between post-exercise and post-rest intake. We found a differential impact of biological and behavioral characteristics on total post-exercise energy intake in men and women. In men, only fasting (baseline) concentrations of appetite-regulating hormones (peptide YY [PYY, β=0.88, P<0.001] and adiponectin [β=0.66, P=0.005] predicted total post-exercise energy intake, while in women, only habitual exercise (β=−0.44, P=0.017) predicted total post-exercise energy intake. Predictors of compensatory intake (intake – exercise expenditure) were almost identical to those of total intake. The difference in energy intake between exercise and rest was associated with VO 2peak (β=−0.45, P=0.020), fasting PYY (β=0.53, P=0.036), and fasting adiponectin (β=0.57, P=0.021) in men but not women (all P>0.51). Our results show that biological and behavioral characteristics differentially affect total and compensatory post-exercise energy intake in men and women. This may help identify individuals who are more likely to compensate for the energy expended in exercise. Targeted countermeasures to prevent compensatory energy intake after in post-exercise energy intake, respectively (72% and 48% for energy compensation) but no signi�cant associations with post-exercise energy intake in women were unexpected. In men, every ten pg/mL increase in fasting PYY concentrations and every one ng/mL increase in fasting adiponectin concentrations was associated with an increase in post-exercise energy intake of 96 kcal and 53 kcal, respectively (energy compensation: 94 kcal and 56 kcal, respectively). We are not aware of previous �ndings of similar sex differences in the association between fasting appetite-regulating hormones and (post-exercise) energy intake. In our study, energy intake following the control condition involving rest. Energy intake after rest was associated with weight and FFM as well as cardiorespiratory �tness (VO 2peak and maximal power). Of note, only absolute but not relative VO 2peak were signi�cant predictors of post-rest energy intake, suggesting that this association was driven by the signi�cant predictors of weight, FFM, and sex, which have repeatedly been shown to predict meal size and single meal food intake. 22–24 When assessing predictors of the difference in energy intake between after exercise and after rest, we found signi�cant associations with cardiorespiratory �tness, in this case, both relative and absolute VO 2peak , for men but not women. Further, the associations revealed a turning point at 40.9 mL/kg/min or 3.0 L/min, respectively. Individuals with average-to-above-average �tness seem to have reduced total energy intake post-exercise compared to post-rest while those with below-average �tness seem to have increased total energy intake post-exercise compared to post-rest. The �nding of greater post-exercise energy intake in individuals with lower �tness compared to those with higher �tness is supported by previous �ndings showing that individuals with higher compared to lower �tness (mean VO 2peak of 51.6 vs. 37.0) compensated after an acute exercise session compared to after rest. 37 Additionally, this relationship may be in�uenced by higher body fat accumulation, which often co-occurs with lower �tness and has been shown to predict greater post-exercise energy compensation due to a progressively increasing impairment of energy balance. 38