The Effects of If-Then Plans on Weight Loss: Results of the 24-Month Follow-up of the McGill CHIP Healthy Weight Program Randomized Controlled Trial

Abstract

Background: The NIH-developed Diabetes Prevention Program (DPP) is successful in achieving clinically significant weight loss in individuals with overweight/obesity when delivered one-on-one. However, due to high cost of implementation, the long-term effectiveness remains limited. In response, a group-based version of the program, called the National DPP, was developed. The average weight loss following participation in this program was only about 3.5% with low long-term weight loss maintenance. Purpose: We aimed to optimize weight loss outcomes of the National DPP by integrating the habit formation tool of if-then plans into the program. Results at 3 and 12 months of participation showed no between-group differences between standard and enhanced DPP but higher weight loss in both groups compared to the National DPP. This paper reports the long-term weight loss maintenance data following participation in the program. Methods: Of the 172 participants enrolled at the beginning of the study, data from 110 participants was available and analyzed at 24 months, i.e. 12 months following the end of the 12-month intervention. Results: No between-group difference in weight loss maintenance was seen. Pooled results showed a significant weight regain from 12 to 24 months, i.e. an average of 7.85lbs of the 20.36lbs lost. However, participants from both groups were still 12lbs or 6.13% lighter at 24 months than at baseline. Conclusion: If-then plans did not result in a higher percentage of weight loss at 24-month follow-up. However, at 24 months, both groups maintained a significant portion of the weight lost at the end of intervention.