Psychosocial predictors of physical activity change among college students in an obesity prevention trial

Background: Moderate-to-vigorous physical activity (MVPA) is critical for maintaining a healthy weight, although little is known about psychological barriers to maintaining MVPA in at-risk groups. Identifying characteristics associated with poor MVPA maintenance in obesity prevention programs could improve participant outcomes. Methods: Toward this end, we examined predictors of MVPA in an obesity prevention trial for college students at risk for weight gain (n = 333; 72% female, mean BMI = 23.4 kg/m2). Participants engaged in 1 of 3 weight control interventions and in 4 assessments over 12-month follow-up (ie, measured height/weight, self-reports of psychosocial characteristics, 4 days of accelerometer wear). Results: Multilevel modeling analyses showed that across conditions, participants decreased total MVPA minutes per week over 12 months (B = -5.48, P < .01). Baseline self-report scores for both impulsiveness and cognitive dissonance regarding engaging in unhealthy behaviors negatively predicted MVPA over time. Participants higher (vs. lower) in baseline impulsiveness (B = -6.89, P = .03) and dissonance (B = -4.10, P = .04) began the study with more MVPA minutes, but showed sharper declines over time. Conclusions: Targeted MVPA-focused intervention for students who show elevated impulsiveness and cognitive dissonance may improve both MVPA and weight control outcomes for these individuals.