Background: There is a dearth of research into mental disorders amongst Aboriginal and Torres Strait Islander peoples (herein First Australians) and especially into eating disorders. In order to understand the healthcare needs of this population, accurate prevalence data is needed. This study aimed to estimate the prevalence of eating disorders amongst First Australians at the diagnostic threshold level and to compare clinical features and health related quality of life (HRQoL) in First and other Australians with and without an eating disorder. Methods: Data were sourced from the general population 2015 and 2016 Health Omnibus Surveys in South Australia. Trained interviewers conducted via face to face interviews with 6052 people over 15 years old. Eating disorder questions were based on the Eating Disorder Examination and Health Related Quality of Life (HRQoL) measured with the Short-Form 12 v1. The response and participation rates were over 50% and 68% respectively in both surveys. Body Mass Index (BMI) and First Australian status were derived from interview questions. Data were weighted to population norms and analysed using statistical methods for complex surveys. Results: Twenty-five of 92 (27%) First Australian survey respondents had an eating disorder (majority Other or Unspecified Feeding or Eating Disorder characterised by recurrent binge eating). This was significantly more than the prevalence of other Australians with an eating disorder group (p = .04). First Australians with an eating disorder had higher levels of weight/shape overvaluation than all other groups. They were also younger and had poorer Mental HRQoL (MHRQoL) than other Australians without an eating disorder. On logistic regression, First Australian status was not independently associated with having an eating disorder, however, age, Body Mass Index (BMI) and MHRQoL emerged as significant independent variables for the increased rate of eating disorders in First Australians. Conclusions: Eating disorders were very common in First Australians and were associated with high levels of overvaluation, binge eating frequency and poor MHRQoL. High levels of overvaluation were unexpected. The implications of these findings include an urgent need for further research, and the development of culturally appropriate assessment instruments and treatments for First Australians with eating disorders
