The Association between Obesity and Depression: The Mediating Roles of Perceived Overweight, Body Image Dissatisfaction, and Weight-based Rejection Sensitivity

Background: The rising prevalence of overweight in Taiwan has raised concerns about its psychological impact, particularly depression. Research suggests that perceived overweight, body image dissatisfaction, and weight-based rejection sensitivity may mediate this relationship. However, limited studies have explored these mechanisms in Taiwanese populations. Aim: To examine whether perceived overweight, body-image dissatisfaction, and weight-based rejection sensitivity mediate the association between body mass index (BMI) and depressive symptoms in Taiwanese adults. Methods: In this cross-sectional survey, 607 participants (291 university students, 316 community residents) completed measures of BMI, perceived overweight, body-image dissatisfaction, weight-based rejection sensitivity, and depressive symptoms. Parallel and serial mediation analyses with 5000-sample bootstrap were conducted, controlling for gender, age, and earliest overweight age. Results: BMI was indirectly associated with depressive symptoms through perceived weight (β = 0.12, P = 0.022). Perceived weight further predicted depression through body image dissatisfaction (β = 0.22, P < 0.001) and rejection sensitivity (β = 0.12, P < 0.001). BMI also contributed to greater body image dissatisfaction (β = 0.08, P < 0.001) and rejection sensitivity (β = 0.07, P < 0.001) through heavier perceived weight, leading to more depressive symptoms. Conclusion: Depressive symptoms associated with higher BMI are largely driven by individuals’ perception of being overweight and the resulting body dissatisfaction and anticipated weight stigma, rather than weight itself. Interventions should, therefore, target weight perception, promote positive body image, and reduce weight-related stigma to mitigate depression risk.