Prospectively predicting dietary restraint: the role of interpersonal self-efficacy, weight/shape self-efficacy, and interpersonal stress.

Dietary restraint is often touted as a path to more than just weight loss. For example, research suggests that women diet to seek social acceptance through their resulting weight loss1. When experiencing interpersonal stress, women with high self-efficacy related to attaining a desired body weight/shape but low interpersonal self-efficacy may thus turn to dieting to both regain a sense of self-efficacy and to indirectly work toward interpersonal change. The current study investigates the association between dietary restraint and the combination of interpersonal self-efficacy, weight/shape self-efficacy, and interpersonal stress. Interpersonal relationships can be a key component of self, particularly for women2. Relationship difficulties can thus threaten women’s sense of self. This may help explain the devastating emotional and psychological impact when relationships end or are feared to end3– 4. Yet, relationships inherently involve lack of control to some degree, given that they are dependent on other’s reciprocation. A coping strategy for interpersonal stress that would counter this lack of control would involve engaging in behaviors that promote self-efficacy (confidence in ability to successfully execute behaviors necessary for desired outcomes5). When women have low interpersonal self-efficacy (i.e., they feel little confidence in their ability to directly influence their relationships in their desired direction, e.g., through social skills) but high self-efficacy in another domain (e.g., appearance), they may consequently cope by exercising control in the domain in which they have high self-efficacy. Links between the interpersonal domain and the appearance domain make the appearance domain a particularly likely alternative for coping1. Research supports an important connection between interpersonal stress and dietary restraint. For example, positive correlations have been found between dietary restraint and the stressors of friendship alienation, conflict, and competitiveness6–7 and between dietary restraint and the romantic relationship stressors of psychological aggression, lack of sexual intimacy, and abuse8–10. Furthermore, escalations in dietary restraint have been attributed to interpersonal problems/stress by outpatients with anorexia nervosa11. In contrast, a relationship between decreased interpersonal stress and decreased dietary restraint is suggested by reports that friendships lead to recovery for outpatients with anorexia nervosa12. Results from a broader examination of the literature further bolster the link between interpersonal stress and dietary restraint. For example, fear of negative evaluation by others (arguably, an example of interpersonal stress) is positively correlated with restrictive eating attitudes13. One way that interpersonal stress may foster increased dietary restraint is through associations between women’s bodies and the interpersonal14. For example, Gerner and Wilson found a link between increased dietary restraint and the belief that being thin will improve friendships15. This connection between the body, friendships, and dietary restraint is further echoed in research finding that perceived friend concern with weight is positively correlated with dietary restraint7 and that fear of being left behind by friends because of their body and weight motivates dieting in adolescent women16. Thus, women experiencing interpersonal stress may increase dietary restraint to lose weight/become thinner if they believe that altering their body in this way will resolve interpersonal stress. Although same sex friendships, opposite sex friendships, and romantic relationships are all of high relevance to a young woman’s life, stress from these relationships may not equally influence dietary restraint. Research distinguishing the effects of different types of interpersonal stress on eating has generally been limited to bulimic behavior. For example, Thelen, Kanakis, Farmer, and Pruitt found higher levels of dissatisfaction with male friendships/intimate relationships, but not female friendships, to be related to higher levels of bulimic symptomatology17. In addition, higher rates of bulimia have been found on college campuses that emphasize dating18 and on co-ed floors of residence halls19. Whether this type of differential interpersonal influence applies to dietary restraint warrants investigation. How the theoretically meaningful combination of interpersonal self-efficacy, weight/shape self-efficacy, and interpersonal stress influences dietary restraint is an emerging topic of investigation. Dieting among undergraduate women has been found to be most elevated among those with the combination of high interpersonal perfectionism, low interpersonal self-efficacy, high interpersonal stress, and high weight/shape self-efficacy20. The current study more closely examines the role of interpersonal stress through three models, each with a different type of interpersonal stress: stress from same sex friendships, opposite sex friendships, or romantic relationships. Women with low confidence in their interpersonal abilities (i.e., who have low interpersonal self-efficacy) were predicted to have the highest levels of dietary restraint when experiencing elevated interpersonal stress if they were especially confident in their ability to control their weight or shape (i.e., they had high weight/shape self-efficacy). For these women, dietary restraint may function as a coping mechanism by providing a sense of control or efficacy (over weight/shape) to compensate for their limited sense of control or efficacy related to interpersonal stress.