First versus repeat treatment with a lifestyle intervention program: attendance and weight loss outcomes

Objective: Following unblinding of the Diabetes Prevention Program (DPP) results, a 16-session lifestyle intervention program was offered to all study participants, including those who had initially been randomized to lifestyle treatment. This study compares the effects of the lifestyle program between participants who had previous exposure and those who had not. Design: A 16-session behavioral intervention was conducted in groups at each of the 27 DPP sites during a transitional (bridge) period from the DPP trial to the DPP Outcomes Study (DPPOS). Session participation for this 6-month behavioral weight loss program was confirmed by originally randomized treatment groups. Subjects and measurements: Independently assessed weight measurements were available within a 7-month period before and after the program for 2808 ethnically diverse participants. Results: Participants from the lifestyle group in the DPP were the least likely to attend a repeat offering of a 16-session behavioral weight loss program conducted in groups. Weight loss during the transitional lifestyle program was strongly related to the duration of attendance in the three groups that were participating in the program for the first time (metformin, placebo and troglitazone), but not related to amount of earlier weight loss. Conclusion: Individuals who were naive to the behavioral program lost a greater amount of weight and this was strongly related to their degree of participation. A second exposure to a behavioral weight loss program resulted in unsatisfactory low attendance rates and weight loss. International Journal of Obesity (2008) 32, 1537-1544; doi: 10.1038/ijo.2008.134; published online 19 August 2008