Dietary intake and physical activity behavior in commercial weight-loss program users: An application of organismic integration theory

Background Current estimates indicate the prevalence of excess body weight in adults inhabiting westernized countries is increasing (Shields, Gorber, & Tremblay, 2009). Many adults use dieting strategies and leisure-time physical activity (LTPA) in an attempt to mitigate the negative health effects of excess body weight (Franz et al., 2007), yet long-term adherence to these lifestyle behaviors central to weight management is poor (French, Jeffery, & Murray, 1999). Motivation has been identified as a critical variable underpinning the decision to engage in, and maintain, healthy lifestyle habits in people seeking to lose fat mass or control body weight (Mihalko et al., 2004). Study Purpose The purpose of this study was to examine the motivational basis for LTPA and healthy eating behaviors within a sample of commercial weight-loss program users. Methods Participants (N = 37; 83.80 percent female; Mage = 32.45 years; SDage = 10.86 years) enrolled in commercial weight-loss programs (MDuration= 0.74 years; SDDuration = 1.18 years) completed a self-report survey on a single occasion via a secure internet location. Results Descriptive statistics indicated that participants endorsed more autonomous than controlled motives for LTPA and healthy eating. Autonomous motives were positively correlated with more frequent daily fruit and vegetable intake, engagement in more strenuous types of LTPA, and greater frequency of typical LTPA per week. Both amotivation and external regulation were negatively correlated with LTPA, yet were unrelated to daily fruit and vegetable intake. Introjected regulation was unrelated to daily fruit and vegetable intake but positively associated with more frequent engagement in LTPA during a typical week. Summary Overall, the results of this investigation support the importance of understanding the motivational basis for healthy eating and LTPA amongst users of commercial weight-loss programs, and provide additional evidence supporting the positive link between motives centered on the personal values, congruent beliefs, and interest or enjoyment with adaptive health behaviors integral to weight control.