The purpose of this study was to assess the association between childhood abuse and adult obesity.We performed a comprehensive meta-analysis, which included studies that reported odds ratio (OR) estimates with 95% confidence intervals (CI). Summary estimates of association were obtained using a random-effects model. Heterogeneity among studies was evaluated using Cochran Q and I2 statistics.A total of 22 cohort studies (3 prospective, 19 retrospective) were included in this meta-analysis. The pooled OR was 1.23 (95% CI, 1.16-1.31). All 4 subcategories of abuse were associated with adult obesity: physical abuse (OR, 1.26; 95% CI, 1.10-1.42), psychological abuse (OR, 1.20; 95% CI, 1.07-1.33), sexual abuse (OR, 1.22; 95% CI, 1.05-1.38), and neglect (OR, 1.22; 95% CI, 1.12-1.32). Moreover, dose-response analysis showed that severe abuse (OR, 1.38; 95% CI, 1.14-1.1.62) was significantly associated with adult obesity compared with light/moderate abuse (OR, 1.01; 95% CI, 0.84-1.18). Although slight publication bias was observed (Egger test P = .05), effect sizes remained statistically significant in sensitivity analyses.This research demonstrated a remarkably consistent association between childhood abuse and adult obesity. Medical practitioners need to be aware of the important role of childhood abuse in the development of obesity.