Malleability of weight-biased attitudes and beliefs: A meta-analysis of weight bias reduction interventions

•Weight bias exists across many important life domains and is associated with negative outcomes.•This meta-analysis examined the effectiveness of weight bias interventions.•A small to medium effect of interventions on weight-biased attitudes and beliefs was found.•Planned moderators were not significant but revealed noteworthy trends.•Further study is needed to determine which types of interventions are most effective.

Weight bias exists across many important life domains, necessitating interventions designed to reduce weight-biased attitudes and beliefs. Though the effectiveness of weight bias interventions has been questioned, to our knowledge no meta-analysis of these interventions has been conducted. This meta-analysis evaluated the impact of weight bias interventions on weight-biased attitudes and beliefs and explored potential moderators. Interventions were eligible if they used an adult sample and a validated measure of weight-biased attitudes, which resulted in the inclusion of 30 studies represented in 29 articles. A random effects approach using inverse weights resulted in a mean effect size estimate of g = −0.33 (lower scores indicate less weight bias) for both attitudes and beliefs. Intervention type, publication type, and population type were not significant moderators but demonstrated noteworthy trends. Results reveal a small, positive effect of weight bias interventions on weight-biased attitudes and beliefs and provide useful information for future interventions.