Testing motivational processes in commercial weight-loss program users: Is there a 'spill-over' effect on weight-control behaviors?

Objective(s): To determine the role of motivational 'spill-over' effects on weightcontrol behaviors (physical activity and healthy eating) in commercial weight-loss program (CWLP) users. Study Design: A non-experimental, cross-sectional design was employed to recruit women (93.33% Caucasian/White) enrolled in one of four self-selected CWLP. Participants (N = 90) completed assessments of physical activity/healthy eating motives plus weight-control behaviors using a web-based interface. Results: CWLP users endorsed more autonomous than controlled motives for weight-control behaviors while also displaying low levels of amotivation. Path analyses supported (a) direct effects linking autonomous motives to more frequent weight-control behaviors, and (b) significant indirect effects linking autonomous not controlled motives from other behavioral domains with adaptive weight-control behaviors. Conclusions: Overall, this investigation supports the important role of autonomous (not controlled) motives for weight-control behavior, and implies that motivational 'spillover' is likely to occur between behavioral domains focused on weight-control only when the source of motivation is autonomous in nature. Health professionals working with adults using CWLP may wish to tailor intervention efforts to key strategies fostering autonomous motives that in turn positively impact weight-control.