The overvaluation of weight or shape as a defining feature of binge eating disorder : a population-based investigation of psychopathology and psychosocial impairment

Abstract

Binge eating disorder (BED) is characterised by the consumption of an abnormally large amount of food and the experience of a loss of control over one's eating. Concerns have been raised around the absence of a cognitive criterion, namely overvaluation of weight or shape toward one's self-worth (overvaluation), in current BED diagnostic criteria. The current thesis aimed to investigate the status of overvaluation within BED by means of a series of community-based studies. Study one examined eating disorder psychopathology, distress and psychosocial functioning across groups of women with probable BED with and without overvaluation, obese individuals who reported no binge eating (obese controls) and normal-weight individuals who reported no binge eating (healthy controls). Women with probable BED and overvaluation reported significantly greater eating disorder psychopathology, distress, and poorer psychosocial functioning. No significant differences on any outcome measures were found between probable BED without overvaluation and obese control groups. Study two examined eating disorder psychopathology, generic and disease-specific quality of life across groups of women with probable BED with and without overvaluation, obese controls and healthy controls. A comparison group of individuals with BED receiving specialist treatment was also considered. Participants with probable BED and overvaluation reported significantly greater eating disorder psychopathology and poorer generic and disease-specific quality of life, comparable to BED patients receiving specialist treatment. Participants with probable BED without overvaluation did not differ from obese controls on any these measures. Study three examined eating disorder psychopathology, distress and quality of life among female adolescents with loss of control (LOC) eating across groups of LOC eating with and without overvaluation, obese control and healthy control. Participants in the LOC eating with overvaluation subgroup reported significantly greater eating disorder psychopathology than all other groups, while levels of eating disorder psychopathology did not differ between LOC eating without overvaluation and obese control groups. On measures of distress and quality of life there were no significant differences between LOC eating with and without overvaluation groups. Study four examined eating disorder psychopathology and emotion regulation (ER) difficulties, a core theorised aetiological mechanism in BED, across groups of women with probable BED with and without overvaluation, obese controls and healthy controls. A comparison group of individuals with a clinical BED diagnosis was again also considered. Participants with probable BED and overvaluation reported significantly greater ER difficulties, comparable to BED patients receiving specialist treatment. Participants with probable BED without overvaluation more closely resembled obese controls with respect to ER difficulties. The current findings provide evidence that overvaluation indicates a significantly more severe presentation in terms of eating disorder psychopathology, psychosocial impairment, generic and eating disorder specific quality of life as well as ER difficulties. It highlights the need for reference to overvaluation in the diagnostic criteria for BED and questions the clinical significance of BED in the absence of overvaluation. Though further research is needed, particularly in adolescents, the inclusion of overvaluation in diagnostic criteria would enhance the clinical utility of the BED diagnosis and become consistent with a transdiagnostic conceptualisation of eating disorder psychopathology. Show more