Abstract
Background/Objectives: Thinness is widely idealized as a standard of beauty, and late school-age girls are increasingly exposed to sociocultural pressures that may be associated with excessive drive for thinness and maladaptive body esteem. These body-related cognitive distortions often emerge regardless of actual weight status and may precede unhealthy dieting behaviors and emotional difficulties. This study aimed to develop and evaluate a school-based Rational Emotive Behavior Therapy (REBT) intervention designed to modify excessive drive for thinness and maladaptive body esteem among late school-age girls. Methods: A quasi-experimental, non-equivalent control group design with repeated measures was employed. Participants were 62 girls in grades 5-6 recruited from two public elementary schools in South Korea (experimental group: n = 30; control group: n = 32). The experimental group participated in a five-week REBT intervention consisting of 10 structured sessions grounded in the A-B-C-D-E model, while the control group received no intervention. Outcomes were assessed at pretest, posttest, and follow-up, including drive for thinness, body esteem, positive affect, negative affect, disordered eating behaviors, and social media overuse. Data were analyzed using repeated measures ANOVA. Results: Significant group × time interaction effects were observed for drive for thinness, body esteem, positive affect, negative affect, and disordered eating behaviors, with greater changes observed in the experimental group. No significant group × time interaction was found for social media overuse. Conclusions: The school-based REBT intervention was associated with reductions in excessive drive for thinness and improvements in body esteem and was also associated with changes in emotional outcomes and reductions in disordered eating behaviors among late school-age girls. These findings support early cognitive modification as a preventive strategy within school settings.