Variability in Weight Change Early in Behavioral Weight Loss Treatment: Theoretical and Clinical Implications.

Abstract

Response early in weight loss treatment predicts long-term weight change. Weight variability, independent of absolute early weight change, may also relate to long-term outcomes. This study examined whether weight variability early in treatment predicted later weight loss and maintenance. Participants were 183 completers of a yearlong behavioral weight loss program (mean age = 51, 81% female, 69% white, mean BMI = 35  kg/m² ). Weight variability was calculated using weights from the first 6 and 12 weekly treatment sessions. Multiple linear regressions examined whether weight variability predicted subsequent weight change 6, 12, and 24 months later. Weight variability over 6- and 12-week periods predicted less subsequent weight loss at 12 months (6-week: β = 0.18, P = 0.02; 12-week: β = 0.33, P < 0.01) and 24 months (6-week: β = 0.17, P = 0.03; 12-week: β = 0.15, P = 0.05). Relationships held when adjusting for covariates. Weight variability was more strongly associated with 6-month weight change in men than women (β = 0.27, P = 0.01). Elevated weight variability early in a weight loss program predicted poor long-term outcomes, possibly reflecting inconsistent weight control behaviors. Tracking weight variability could prove useful for improving treatment outcomes.