The aim of the present study was to investigate the mediating role of body image concerns in the relationship between metacognitive beliefs, emotional dysregulation, and intolerance of uncertainty with the severity of bulimia nervosa symptoms in women. This study was descriptive-correlational and based on structural equation modeling. The statistical population included all women with bulimia nervosa referring to medical centers in Tehran in 1403, from which 385 people were selected through purposive sampling. The research instruments included the Body Image Concerns Questionnaire, Metacognitive Beliefs Questionnaire, Difficulty in Regulating Emotions Scale, Intolerance of Uncertainty Scale, and Eating Disorder Assessment Questionnaire, and the data were analyzed using AMOS software. The results showed that metacognitive beliefs, emotional dysregulation, and intolerance of uncertainty have a positive and significant relationship with body image concerns; also, body image concerns had a significant relationship with the severity of bulimia nervosa symptoms. Path analysis showed that all three variables mentioned have an indirect and significant effect on the severity of bulimia nervosa symptoms through body image concerns. As a result, it can be said that body image concerns play an important mediating role in the relationship between cognitive-emotional variables and the severity of bulimia nervosa disorder; accordingly, therapeutic interventions should focus on correcting dysfunctional metacognitive beliefs, improving emotion regulation, and increasing tolerance for uncertainty in order to reduce the symptoms of bulimia nervosa disorder in patients by reducing body image concerns.
