Behavioral and psychological factors associated with 12-month weight change in a physical activity trial

Examining behavioral and psychological factors relating to weight stability over a 1-year period is of public health importance. we conducted a physical activity (pa) intervention trial for women (n=247; mean age=47.5±10.7; mean bmi=28.6±5.3) in which participants were assigned to one of three groups (two pa and one contact-control). by month 12,participants achieved 140.4±14.82 min of pa/week,with no group differences. weight status change from baseline to month 12 was categorized: no change (n=154; 62.4%); increase (n=34; 13.8%); decrease (n=59; 23.9%). discriminant function analyses indentified two statistically significant dimensions associated with weight change. dimension 1 was positively weighted by mood (0.73) and self-efficacy (0.79); dimension 2 was positively weighted to change in physical activity (0.58) and fat consumption (0.55). results provide further evidence for the importance of behavior in long-term weight maintenance,particularly physical activity and dietary fat. these findings also provide evidence for the importance of addressing psychosocial variables,in particular depressed mood and self-efficacy. © 2011 melissa a. napolitano and sharon hayes.