Long-term effects of an internalized weight stigma intervention: A randomized controlled trial

To test the long-term effects of a group-based, psychological intervention designed to reduce internalized weight stigma (IWS, i.e., self-stigma), delivered in combination with behavioral weight loss (BWL) treatment, compared to BWL alone.

Adults with obesity who had experienced and IWS (N = 105, M_age = 49 years, 90.5% women, 70.5% White, 24.8% Black, M_BMI = 38 kg/m²) were randomized to receive BWL with the Weight Bias Internalization and Stigma (BIAS) Program or BWL alone. Participants received weekly group treatment for 20 weeks, followed by 52 weeks of monthly and every-other-month sessions. Percent weight change at Week 72 was the primary outcome, with secondary outcomes of weight change at other time points; physical activity (measured by accelerometry, interview, and self-report); cardiometabolic risk factors; and psychological and behavioral outcomes. Intention-to-treat analyses used linear mixed models to test for between-group differences. Treatment acceptability was assessed.

Participants in the BWL + BIAS versus BWL group lost 2 percentage points more of baseline weight at Week 72, which was not a significant difference (mean weight change = -7.2% vs. -5.2%, 95% CI [-4.6 to 0.6], p = 0.14, d = 0.18). The BWL + BIAS (vs. BWL) group produced significantly greater improvements in weight self-stigma, eating self-efficacy, and some aspects of quality of life at specific time points. Most outcomes improved significantly over time but did not differ between groups. The trial had high retention and treatment acceptability, with higher ratings in the BWL + BIAS versus BWL group.

No significant differences in weight loss were observed between the BWL + BIAS versus BWL group. Possible benefits of addressing weight stigma in weight management warrant further investigation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).