Two decade researches demonstrated increasing prevalence of Eating Disorders (EDs) among women of Eastern societies (1-5) Thus, investigating the etiological and maintenance models of EDs in these cultures is an important research and clinical issue.
Fairburn (6) proposed a Cognitive Behavioral model for Bulimia Nervosa (CB-BN). The original version of the model explains how overvaluation of shape and weight and their control results in dietary restraint and thereby binge eating and purging behaviors. According to the theory, patients with Bulimia Nervosa (BN) put their self-worth exclusively or largely on their weight and shape. This overvaluation of shape and weight is the core psychopathology of the BN. Therefore, the patients with BN engaged in dietary restraint or other weight control behaviors. However, perfect obey of these inflexible dietary restraint rules is not possible and lead to binge eating episodes. The binge eating episodes, in turn, increases the concerns about weight and shape and thereby play a role in maintenance of dietary rules. Finally, concerns about weight and shape evokes compensatory behaviors after binge eating.
Fairburn et al., (7, 8) extended the original CB-BN model in order to more fully speculate the factors involved in development and maintenance of EDs. The enhanced version of the model illustrates how low self -esteem, clinical perfectionism, interpersonal problems, and mood intolerance interact with the core psychopathology of EDs. In essence, low self-esteem and clinical perfectionism encourage person to duplicate her/his efforts to achieve expected goals about weight and shape. On the other hand, clinical perfectionism and low self-esteem lead to self-criticism after perceived failure. The enhanced version of the model outlines that in a subgroup of patients with EDs interpersonal problems may intensify self-esteem concerns and overvaluation of weight and shape, and elicit binge eating behaviors. Finally, the model proposed that some patients with EDs utilized binge eating and purging as a way of coping with overwhelming aversive mood state.
Consistent with the theory, prospective studies consistently demonstrated that appearance overvaluation and/or body dissatisfaction predict dietary restraint, eating disorder cognitions (9), EDs symptoms (10-13), and binge eating behaviors (14). Also, dietary restraint has been indicated prospectively anticipate binge eating behaviors among women (15), adolescents (16), and children (17). One of these studies reported the predictive role of low self-esteem, and lower level of social support on eating symptomatology (14). Also, a number of path analytic studies tried to evaluate the original and enhanced version of CB- BN model.
Studies using structural equation modelling or path analysis showed that original (18-20) and enhanced version of CB model of EDs fit with the data. (18), (20) and (21) found that low self esteem predicted drive for thinness and/or body disatisfaction which, in tern, anticipated dietary restraint. Dietary restraint predicted binge eating and binge eating predicted purging behaviors. Four studies (19, 22, 23) evaluated the enhanced version of CB-BN model and found that low self esteem and clinical perfectionism associated with overvaluation of shape and weight which, in tern, prognosticate dietary restraint. Dietary restraint corelated with binge eating and benge eating predicted purging behaviors. Finaly, interpersonal problems anticipated dietary restraint and mood intolerance associated with binge eating and purging (19, 22).
However, to our konwledge, the CB-BN model has yet to be evaluated among women of Eastern socities. Thus, the current study aimed to investigate the validity of original and enhanced version of CB-BN model in a sample of Iranian student women. We tried to answer two questions:
1) Whether the original model of CB-BN model offer a valid representation of association btween overvaluation of shape and weight, dietary restraint, binge eating and purging among Iranian student women?
2) Dose the enhanced version of CB-BN model provide a good account of the relationship of low self esteem, clinical perfectionism, interpersonal problems, and mood intolerance with overvaluation of shape and weight, dietary restraint, binge eating and purging among Iranian student women?