Moderators of the relation between physical activity and subsequent energy intake among behavioral weight loss participants

Objective: Behavioral weight loss (BWL) programs prescribe reduced energy intake (EI) and moderate-to-vigorous physical activity (MVPA). However, MVPA may also acutely influence EI, and that relation may depend on body mass index (BMI) and post-MVPA cognitions. This study tested if BMI and post-MVPA cognitions moderated the within-subject relation between MVPA and subsequent EI among BWL participants. Method: Participants were 91 adults with overweight/obesity participating in a yearlong BWL trial. Data were collected during a 3-week midtreatment assessment, with MVPA measured using Fitbit devices, EI via a self-monitoring app, and BMI via wireless scales (weight) and self-reported height. Post-MVPA cognitions included the following: permissiveness to consume more calories, perceived need to replenish one’s body with food, and motivation to lose weight. Results: Multilevel models demonstrated lower BMI and higher perceived need for replenishment amplified the positive relation between MVPA and subsequent EI in the 2-hr post-MVPA period. Exploratory analyses showed increased EI in the 2-hr post-MVPA period was associated with greater daily EI at the trend level, and daily EI was negatively associated with percent weight loss across the midtreatment assessment. Conclusion: Individuals with lower BMI and greater perceived need for replenishment post-exercise had higher EI following MVPA versus no MVPA. Findings suggest greater EI acutely following MVPA may predict greater daily EI, which in turn negatively impacts weight loss. Thus, for optimal weight loss outcomes, it may be important to increase awareness of these EI patterns among relevant subpopulations and encourage planning of EI around MVPA to ensure dietary adherence is maintained.