The present study to our knowledge is the first to provide data on eating disorder features in Australian indigenous peoples derived from a general population sample of older adolescents and adults. The findings support eating disorder problems of subjective and objective binge eating being at least as common if not more common (controlling for secular differences) in indigenous peoples. (Subjective binge eating is where the person perceives an episode of overeating on an amount of food that is not excessively large given the social and cultural context of eating. Objective binge eating is where the person perceives an episode of overeating on an amount of food that is excessively large given the social and cultural context of eating [14, 16].) In addition, the core cognitive feature of an eating disorder, namely weight and/or shape concern, was also as high if not higher in indigenous participants (controlling for secular differences) and levels of restrictive dieting and other compensatory weight control behaviors were similar to non-indigenous. The small numbers of people with Aboriginal or Torres Strait islander who identified their ethnicity precluded statistical comparison of rates of purging behaviors and estimate of diagnostic eating disorder prevalence. However, it can be surmised that eating disorders are likely to be at least as much a problem for indigenous as for non-indigenous Australians. Furthermore, the similar (or greater) prevalence of binge eating behaviors were not explained by secular differences in indigenous such as younger age, higher body weight, gender or income levels.
Caution must be exercised in discussing the results of eating disorder features and gender in the indigenous participants as numbers were very small and there were differences across the two years of survey. The finding that regular binge eating (objective and subjective) was as if not more common in males in 2008 is however in accord with international studies. These have found that unlike anorexia nervosa and bulimia nervosa, binge eating is as common in males as it is in females . In addition in both years we found BMI to be higher in those with regular objective binge eating. This is also consistent with research indicating a higher frequency of disordered and binge eating in the overweight and obese [17, 18].
The present study was limited in that assessment was only at two time points. In addition, the survey instrument has not been validated for cross-cultural use. It also did not record details of the most common types of weight control behaviors, nor details of restrictive dieting nor the types of foods consumed during a binge and it had no assessment of excessive exercise or body composition concerns (such as a favorable regard for increased muscularity as found in previous research ). It would have been desirable to have included assessment of lifetime as well as current prevalence rates. It is important to note that the findings can only be generalized to indigenous Australians living in metropolitan areas with probable less income and education disadvantage than for those living in rural and remote areas. Strengths of the present study were the replication of results in a second survey within 3-years, standardized and rigorous survey methods, including random selection and interview assessment, the good response rates, wide age range and inclusion of both genders. Small numbers preclude analysis of time trends in the indigenous participants but the apparent decrease in rate of eating disorder features needs further study in larger samples and over a longer time period.
The findings are important as they highlight for indigenous Australians the problem of disordered eating and body weight concerns, eating disorder features that are commonly associated with obesity. This is consistent with the increased frequency of obesity related physical health problems such as diabetes, hypertension and the metabolic syndrome which are well recognized as contributing to shortened lifespan and greater morbidity in Aboriginal and Torres Strait Islander peoples. The poor dietary choices that likely underpin these problems can been seen in the wider context of cultural dispossession whereby traditional methods of food preparation and choices of 'plain foods' have often been displaced with pre-prepared 'fast' foods of lower nutritional value. This is exacerbated by the social disadvantage and, as indeed we found, increased health related role impairment of indigenous peoples. More research is needed to investigate the cultural and social context of food and eating and subsequent health problems in indigenous Australians.
The present study points to the need for health professionals to ask about and identify binge eating and other features of disordered eating in indigenous patients presenting with these medical problems. Not only are these important co-morbidities of obesity but they may impede weight management programs and exacerbate co-morbid medical problems such as diabetes  if not addressed. Furthermore, there are real concerns about the role of extreme dietary restriction and other weight control methods in exacerbating bulimic behaviors and contributing to weight gain . On the other hand, psychological approaches in particular cognitive behavior therapy, are effective in reducing binge eating and other bulimic behaviors  and professionally lead behavioral weight management programs may attenuate eating disorder behaviors .