The undue influence of shape and weight on self-evaluation in anorexia nervosa, bulimia nervosa and restrained eaters: a combined ERP and behavioral study

Background. Current theories and nosology assume that the self-evaluation (SE) of individuals with eating disorders (EDs) is unduly influenced by body shape and weight. However, experimental data supporting this link are scarce, and it is not specified which subdomains of SE might be affected. Method. We studied patients with anorexia nervosa (AN), bulimia nervosa (BN) and healthy controls (HC) with an affective priming (AP) procedure (Study 1) to unveil explicit and implicit associations between shape/weight and SE. We used weight/shape-related prime sentences, complemented by affectively congruent and incongruent target words from two SE domains. AP effects were assessed by event-related potentials (ERPs), reaction times (RTs) and subjective ratings. The ratings were also assessed (Study 2) in undergraduate restrained (RES) and unrestrained eaters (UNRES). Results. Study 1 demonstrated stronger AP effects in both ED groups compared to HC on RTs and subjective ratings. ERPs showed AP effects only in the BN group. Restrained eaters showed similar, albeit less pronounced, priming effects on subjective ratings. Conclusions. ED patients associate shape/weight concerns with the non-appearance-related SE domains of interpersonal relationships and achievement/performance. These associations seem to be encoded deeper in BN patients relative to the other groups. Links between shape/weight and SE explain how body dissatisfaction impacts on self-esteem and mood in ED. The existence of similar associations in restrained eaters supports a continuum model according to which increasing associations between shape/weight and SE go along with increasing levels of ED symptoms.