Objective: To test the efficacy of a dissonance-based (DB) intervention in targeting risk factors for eating disorders (EDs) and predisposing factors for muscle dysmorphia (MD) symptoms in body-dissatisfied Brazilian men over 1 year of follow-up and evaluate whether reductions in body-ideal internalization would mediate the intervention’s impact on ED and MD symptoms. Methods: Participants were randomized to a two-session DB intervention (n=89) or assessment-only control (AOC) (n=91), and completed validated measures assessing body-ideal internalization, body dissatisfaction, ED, and MD symptoms at baseline, post-intervention, 1-month, 6-month, and 1-year follow-ups. Results: The DB condition showed significantly greater reductions in MD symptoms and body dissatisfaction compared with the AOC group over a 1-year follow-up, while significant differences were not observed for body-ideal internalization and ED symptoms. Changes in body-ideal internalization from baseline to 1-month follow-up completely mediated the relationship between condition and the changes observed in both ED and MD symptoms. Conclusion: These results provide further evidence of the efficacy of the tested intervention through 1-year follow-up in reducing body dissatisfaction and MD symptoms, but no such result was observed for body-ideal internalization and EDs. Our findings provide support for theoretical models of eating pathology and MD symptoms in Brazilian men. Clinical Trial Registration: Brazilian Registry of Clinical Trials (ReBEC): RBR-27dc264. Objective dissonancebased dissonance based (DB EDs (EDs (MD bodydissatisfied dissatisfied followup follow up bodyideal ideal interventions s Methods twosession two session n=89 n89 n 89 (n=89 assessmentonly assessment only (AOC n=91, n91 n=91 , 91 (n=91) postintervention, postintervention post intervention, post-intervention 1month, 1month month month, 6month, 6month 6 6-month 1year followups. followups ups. ups follow-ups Results followup, up, Conclusion Registration ReBEC (ReBEC) RBR27dc264. RBR27dc264 RBRdc RBR 27dc264. 27dc264 dc RBR-27dc264 n=8 n8 8 (n=8 n9 n=9 9 (n=91 (ReBEC RBR27dc26 27dc26 RBR-27dc26 n= (n= (n=9 RBR27dc2 27dc2 RBR-27dc2 (n RBR27dc 27dc RBR-27dc

Objective: To test the efficacy of a dissonance-based (DB) intervention in targeting risk factors for eating disorders (EDs) and predisposing factors for muscle dysmorphia (MD) symptoms in body-dissatisfied Brazilian men over 1 year of follow-up and evaluate whether reductions in body-ideal internalization would mediate the intervention’s impact on ED and MD symptoms. Methods: Participants were randomized to a two-session DB intervention (n=89) or assessment-only control (AOC) (n=91), and completed validated measures assessing body-ideal internalization, body dissatisfaction, ED, and MD symptoms at baseline, post-intervention, 1-month, 6-month, and 1-year follow-ups. Results: The DB condition showed significantly greater reductions in MD symptoms and body dissatisfaction compared with the AOC group over a 1-year follow-up, while significant differences were not observed for body-ideal internalization and ED symptoms. Changes in body-ideal internalization from baseline to 1-month follow-up completely mediated the relationship between condition and the changes observed in both ED and MD symptoms. Conclusion: These results provide further evidence of the efficacy of the tested intervention through 1-year follow-up in reducing body dissatisfaction and MD symptoms, but no such result was observed for body-ideal internalization and EDs. Our findings provide support for theoretical models of eating pathology and MD symptoms in Brazilian men. Clinical Trial Registration: Brazilian Registry of Clinical Trials (ReBEC): RBR-27dc264. Objective dissonancebased dissonance based (DB EDs (EDs (MD bodydissatisfied dissatisfied followup follow up bodyideal ideal interventions s Methods twosession two session n=89 n89 n 89 (n=89 assessmentonly assessment only (AOC n=91, n91 n=91 , 91 (n=91) postintervention, postintervention post intervention, post-intervention 1month, 1month month month, 6month, 6month 6 6-month 1year followups. followups ups. ups follow-ups Results followup, up, Conclusion Registration ReBEC (ReBEC) RBR27dc264. RBR27dc264 RBRdc RBR 27dc264. 27dc264 dc RBR-27dc264 n=8 n8 8 (n=8 n9 n=9 9 (n=91 (ReBEC RBR27dc26 27dc26 RBR-27dc26 n= (n= (n=9 RBR27dc2 27dc2 RBR-27dc2 (n RBR27dc 27dc RBR-27dc