The relationship between self-monitoring, outcome expectancies, difficulties with eating and exercise, and physical activity and weight loss treatment outcomes

Background/Purpose: During a behavioral weight loss program (BWLP), weight loss and exercise can vary considerably from week to week. Weekly fluctuations in outcome expectancies and perceived difficulties with eating and exercise may be associated with weekly variability in weight loss and exercise. Also, inconsistent self-monitoring of exercise may be associated with poor weight loss and physical activity treatment outcomes. Methods: Forty obese, sedentary participants completed a 6-month BWLP. Body weight, outcome expectancies, and difficulties with eating and exercise were assessed weekly. Weekly self-monitoring of exercise was computed from physical activity diaries. Physical activity, VO2 max, and caloric intake were assessed pre- and posttreatment. Results: Within-subjects analyses indicated that participants exercised less during weeks that participants reported greater difficulties with exercise, relative to weeks participants reported fewer difficulties. Participants lost significantly more weight during weeks that participants reported more positive outcome expectancies and greater difficulties with exercise, compared to weeks participants reported less positive outcome expectancies and fewer difficulties with exercise. Consistent self-monitoring of exercise was associated with fewer difficulties with exercise and greater exercise and weight loss. Conclusions: Interventions that are targeted to increase self-monitoring and to improve transient difficulties with exercise and diminished outcome expectancies may improve BWLP treatment outcomes.