Abstract Irrational beliefs about body size and clothing fit are common psychological concerns that can distort self-perception and affect emotional well-being. These beliefs often involve rigid standards and negative self-evaluations related to clothing choices, appearance, and social approval. This study examined the efficacy of Rational Emotive Behavior Therapy (REBT) in challenging and reducing such irrational beliefs among participants. A randomized controlled trial design was used with 67 participants assigned to either an REBT treatment group or a control group. the Body Size Irrational Beliefs Inventory (BSIBS) and Clothing Fit Irrational Belief Scale (CFIBS) were administered at pre-test, post-test, and follow-up intervals. Data were analyzed using repeated measures ANOVA to evaluate time and group effects. At baseline, both groups were statistically equivalent on BSIBS and CFIBS scores. Post-intervention, the treatment group recorded a substantial decline in BSIBS scores from M = 87.26 (SD = 12.41) to M = 31.79 (SD = 3.70), while the control group’s scores remained high. Similarly, CFIBS scores in the treatment group dropped from M = 139.24 (SD = 14.45) to M = 64.62 (SD = 8.06), whereas the control group scores remained elevated. Repeated measures ANOVA showed significant main effects of group for both BSIBS F(1, 65) = 443.86, p < .001, η² P = 0.872 and CFIBS F(1, 65) = 355.15, p < .001, η² P = 0.845, with large effect sizes. The results support the efficacy of Rational Emotive Behavior Therapy (REBT) in significantly reducing irrational beliefs related to body size and clothing fit. REBT can serve as a powerful intervention for improving psychological outcomes in individuals experiencing distress due to rigid, appearance-related belief systems and maladaptive patterns of thinking.
Oluah et al. (Sun,) studied this question.