Assessment of body image in eating disorders

Abstract

The aim of this Thesis was to delineate what the concept "body image disturbance" represents within the area of eating disorders (Eds) and muscle dysmorphia (MD) in order to lay the foundations for the development of an instrument that could assess all the relevant facets of body image disturbance that play an important role in ED/MD onset and maintenance. This was deemed to be an important contribution to the field because current assessment practices for some of the core tenets of ED psychopathology and ED diagnostic criteria lack strong psychometric properties that would justify its use in research and clinical settings. This Thesis established a new instrument for the assessment of body image disturbance relevant for EDs and MD to be used across gender, body size and in community and clinical samples. Overall, a systematic review, longitudinal study and network analysis study provided more insight into i) which specific facets of body image disturbance exist in the literature; ii) how specific facets have been assessed to date; iii) which facets are more strongly linked to ED symptomatology across gender; and iv) how drive for leanness and muscularity might fit into existing categorisations of body image disturbance. This knowledge, accompanied by existing literature on body image disturbance and EDs, was used to lay foundations for development and validation of the new instrument. Overall, the Multifaceted Instrument for Body image Disturbance (MI-BoD) as well as its six subscales showed good psychometric properties, including internal consistency, measurement invariance, concurrent validity, convergent and divergent validity, and test-retest reliability - with the exception of incremental validity which was not supported for the Total or Dissatisfaction scores. Nonetheless, other subscales seem to explain ED symptoms above and beyond existing measures of the same body image disturbance facets, which supports subsequent use of MI-BoD in research where the aim is to assess overvaluation, preoccupation, fear of weight gain, body checking and body exposure facets of body image disturbance. Future research should aim to validate MI-BoD in other samples, develop norms and, if needed, establish a separate version for children and adolescents. It is my hope that this instrument will help researchers and clinicians working with people who have EDs or MD in comprehensively assessing the diverse facets of body image disturbance that are involved in development, maintenance and recovery of these pernicious disorders.

Date of Award	2023
Original language	English