Beliefs about Binge Eating: Psychometric Properties and Clinical Utility of the Eating Beliefs Questionnaire

Abstract

Binge eating (BE) is a core feature of eating disorder presentations, common to bulimia nervosa, anorexia nervosa (binge/purge type), and binge eating disorder. A sound understanding of the underlying mechanisms that maintain BE is crucial for developing effective treatments. The aim of this thesis was to better understand the metacognitive factors that maintain BE, such as the positive, negative, and permissive beliefs about BE described by Cooper, Wells and Todd (2004). This thesis reports a series of studies that aimed to validate and improve upon an existing measure, the Eating Beliefs Questionnaire (EBQ). The EBQ is a self-report tool that measures positive and negative metacognitive beliefs about BE. The first study aimed to validate the EBQ by conducting a confirmatory factor analysis and investigate the psychometric properties of this measure. The second study extended this measure with the addition of a scale that assesses permissive beliefs about BE. The second study also presented a short-form of the revised three-subscale EBQ, the EBQ-18. A third study validated the factor structure and psychometric properties of the EBQ-18 in both a clinical and non-clinical sample. Across the psychometric studies, the EBQ and EBQ-18 were found to provide valid and reliable measures of beliefs related to BE, with evidence for test-retest reliability, and treatment sensitivity. Furthermore, differences in EBQ and EBQ-18 scores were observed between clinical and non-clinical samples, and clinical cut-off scores were identified. In the final empirical chapter, a metacognitive and behavioural model of BE was proposed and tested using structural equations modelling; the new model provided a good fit to the data. These studies further contribute by enhancing the theoretical understanding of the metacognitive maintaining factors involved in BE.