Prospective Evaluation of Internalized Weight Bias and Weight Change Among Successful Weight-Loss Maintainers

Abstract

Objective: Internalized weight bias (IWB) has been associated with weight regain after intentional weight loss, but reliance on cross-sectional data limits the understanding of this relationship. This study prospectively evaluated IWB as a predictor of weight change in a longitudinal observational study of successful weight-loss maintainers. Methods: National Weight Control Registry participants (maintained 13.6-kg weight loss for ≥ 1 y) were asked to complete an online questionnaire including current weight and Weight Bias Internalization Scale-Modified (WBIS-M) at baseline and 12 months. Results: At baseline, 1,250 of 1,643 eligible individuals completed the baseline assessment (71% female; 94% white; mean age ± SD: 52 y ± 13.1; BMI: 27 ± 5.5). The average WBIS-M score was 3.0 (± 1.3). Study completers (n = 862) reported 2.2% (± 7.8%) weight gain. Higher baseline IWB predicted weight gain among men (n = 254; t = −2.28; P = 0.02) but not women (n = 608; t = 1.22; P = 0.22). A one-point reduction in WBIS-M score at follow-up was associated with a 3.0% weight loss. Conclusions: Among weight-loss maintainers, IWB may be a risk factor for weight gain among men. Weight loss at follow-up was associated with reduced IWB in both men and women. Reliance on female-only samples may limit our understanding of IWB and its implications for weight control.