Consistency in compensatory eating responses following acute exercise in inactive, overweight and obese women. Issue 7 (17th March 2015) - Unick, Jessica L.
Abstract : It is often assumed that some individuals reliably increase energy intake (EI) post-exercise ('compensators') and some do not ('non-compensators'), leading researchers to examine the characteristics that distinguish these two groups. However, it is unclear whether EI post-exercise is stable over time. The present study examined whether compensatory eating responses to a single exercise bout are consistent within individuals across three pairs of trials. Physically inactive, overweight/obese women ( n 28, BMI 30·3 (sd 2·9) kg/m 2 ) participated in three pairs of testing sessions, with each pair consisting of an exercise (30 min of moderate-intensity walking) and resting testing day. EI was measured using a buffet meal 1 h post-exercise/rest. For each pair, the difference in EI (EIdiff = EIex − EIrest ) was calculated, where EIex is the EI of the exercise session and EIrest is the EI of the resting session, and women were classified as a 'compensator' (EIex >EIrest ) or 'non-compensator' (EIex ≤ EIrest ). The average EI on exercise days (3328·0 (sd 1686·2) kJ) was similar to those on resting days (3269·4 (sd 1582·4) kJ) ( P = 0·67). Although EI was reliable within individuals across the three resting days (intraclass correlation coefficient (ICC) 0·75, 95 % CI 0·60, 0·87; P < 0·001) and three exercise days (ICC 0·83, 95 % CI 0·70, 0·91; P < 0·001), the ICC for EIdiff across the three pairs of trials was low (ICC 0·20, 95 % CI − 0·02, 0·45; P = 0·04), suggesting that compensatory eating post-exercise is not a stable construct. Moreover, the classification of 'compensators'/'non-compensators' was not reliable ( κ = − 0·048; P = 0·66). The results were unaltered when 'relative' EI was used, which considers the energy expenditure of the exercise/resting sessions. Acute compensatory EI following an exercise bout is not reliable in overweight women. Seeking to understand what distinguishes 'compensators' from 'non-compensators' based on a single eating episode post-exercise is not justified.