Impact of a residential program on the psychological needs, motivation and physical activity of obese adults: A controlled trial based on Self-Determination Theory

Purpose: This study aimed to examine the increased benefits of a Self Determination Theory (SDT)-based motivational component on psychological needs’ fulfillment, self-determined motivation and Physical Activity (PA) of obese patients taking part in a rehabilitation program. Methods: Fourty-nine obese adults (mean age = 52 years, mean BMI = 38.25 kg/m 2 ) attended a 3-week residential intervention. Patients in the Motivation group ( n  = 24) received a standard care plus SDT-based intervention ( i.e. , improved supervised PA sessions + a 1-hour motivational session). Patients in the Control group ( n  = 25) only benefited from standard care. Psychological needs and motivation were measured at baseline, at the end of the program and one month after. PA was measured at baseline and one month after the end of the program. Repeated measures ANOVAs were performed to compare the evolution of the variables between groups. Results: The results indicated that participants from both groups displayed significant changes in their perceived autonomy, relatedness, intrinsic motivation and integrated regulation between the beginning and the end of the program. Next, participants from both groups showed a decrease in perceived relatedness between the end of the program and one month after. Last, the participants from the Motivation group reported greater increase of their PA scores between the beginning of the program and one month after as compared to those in the Control group. Conclusions: Obesity interventions should integrate motivational components in order to promote behavior maintenance after programs have ended.