Short-term Weight Loss Patterns, Baseline Predictors, and Longer-term Follow-up within a Randomized Controlled Trial

OBJECTIVE: To examine weight loss patterns and predictors among participants in a primary care-based translation study of the Diabetes Prevention Program lifestyle intervention. DESIGN AND METHODS: Cluster analysis identified short-term (12-week) weight loss patterns among 72 intervention participants. Analysis of variance assessed cluster differences in weight loss maintenance at 15-month follow-up. Discriminant analysis identified baseline characteristics that best differentiated between clusters. RESULTS: Participants had baseline mean (SD) age of 55.0 (10.8) years and BMI of 31.9 (5.2) kg/m(2). Cluster analysis identified three short-term weight loss patterns: modest (n=15; 21%), moderate-and-steady (n=43; 60%), and substantial-and-early (n=14; 19%). Only participants with the latter two patterns achieved clinically significant (≥ 5%) short-term weight loss and maintained it at 15 months. On discriminant analysis, the modest cluster was most differentiated from other clusters by high friend encouragement for dietary change, high obesity-related problems, and low physical well-being. The moderate-and-steady cluster was differentiated by lower physical activity, family encouragement, and depression symptoms. CONCLUSION: Results provide insight into the heterogeneity of response to an effective lifestyle intervention by identifying short-term weight loss patterns and their baseline predictors and relationship to 15-month success. If replicated, results may help tailor strategies for participant subgroups in weight loss programs.