KMAN Publication Inc. (KMANPUB) Applied Family Therapy Journal (AFTJ) 3041-8798 In Press 2027 03 01 Developing a Structural Equation Model of Disordered Eating Behaviors in Patients With Obesity Based on Perfectionism and the Behavioral Activation/Inhibition Systems, With the Mediating Role of Emotion Dysregulation Developing a Structural Equation Model of Disordered Eating Behaviors in Patients With Obesity Based on Perfectionism and the Behavioral Activation/Inhibition Systems, With the Mediating Role of Emotion Dysregulation 1 17 EN Journal Article 2026 05 07 <p><strong>Objective:</strong> The present study aimed to develop and test a structural equation model of disordered eating behaviors in patients with obesity based on perfectionism and the behavioral activation/inhibition systems, with the mediating role of emotion dysregulation.</p> <p><strong>Methods and Materials: </strong>This descriptive-correlational study employed a structural equation modeling approach. The statistical population consisted of all women with obesity and a body mass index greater than 30 who attended the Baraka Obesity Treatment Clinic in Tehran during 2025–2026. Of these individuals, 250 were selected through convenience and voluntary sampling. The data collection instruments included the Eating Attitudes Test developed by Garner et al. (1982), the Frost Multidimensional Perfectionism Scale (Frost et al., 1990), the Behavioral Inhibition System/Behavioral Activation System Scales developed by Carver and White (1994), and the Difficulties in Emotion Regulation Scale developed by Gratz and Roemer (2004), all of which had demonstrated satisfactory validity and reliability in Iranian samples. The data were analyzed using Pearson’s correlation coefficient and structural equation modeling in LISREL.</p> <p><strong>Findings:</strong> The findings indicated that the conceptual model had an acceptable fit, CFI = .96, RMSEA = .069, and χ²/df = 1.70. Perfectionism had significant direct effects on disordered eating behaviors (β = .18, p &lt; .05) and emotion dysregulation (β = .48, p &lt; .001). The behavioral activation system (BAS) and behavioral inhibition system (BIS) had significant direct effects on emotion dysregulation (β = .25 and β = .38, respectively, p &lt; .01), whereas their direct effects on disordered eating behaviors were not significant. The indirect effect of perfectionism on disordered eating behaviors through emotion dysregulation was confirmed (β = .264), indicating partial mediation. In contrast, emotion dysregulation fully mediated the relationships of BAS (β = .137) and BIS (β = .209) with disordered eating behaviors. The final model explained 44% of the variance in disordered eating behaviors and 52% of the variance in emotion dysregulation.</p> <p><strong>Conclusion:</strong> The findings suggest that emotion dysregulation functions as a key mediating mechanism in the relationships of perfectionism and behavioral brain systems with disordered eating behaviors among women with obesity. Therefore, psychological interventions designed to improve emotion-regulation skills and modify perfectionistic standards may contribute to reducing disordered eating behaviors and facilitating more effective obesity management. Future research should test this model in diverse populations, including men and different age groups, using longitudinal designs.</p> https://journals.kmanpub.com/index.php/aftj/article/download/5901/11298