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Comparing Objective and Subjective Binge Eating

A combination of the two types of binge eating led to higher BMIs. 

Episodes of objective binge eating (OBE) are among the core diagnostic criteria for bulimia nervosa and binge eating disorder, and can also occur in persons with anorexia nervosa (AN). (Coincidentally, the abbreviation OBE was coined in the EDE to signify “objective bulimic episode.”) The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders(DSM-5) defines OBE episodes as a sense of loss of control over eating in a specified time frame, during which the amount of food consumed is definitely larger than what most people would eat under similar circumstances. The definitely large amount of food is not only subject to clinical judgment but also excludes the other form of binge eating, subjective binge eating (SBE). SBE is also closely related to an OBE that is a common experience among many people with eating disorders and in the general population.

Dr. Natalie Li and colleagues at Western Sydney University, Penrith, New South Wales, and Macquarie University,  also in Sydney, recently compared the sociodemographic profiles and burden of OBE vs. SBE in a population-based survey of 3028 adult men and women (BMJ Open. 2019;9e024227; doi:10.1136/bmjopen-2018-024227). The Australian researchers sought to determine whether there are differences in sociodemographic profiles, such as age, gender, educational attainment, and levels of distress about binge eating episodes, overvaluation and health-related quality of life among three study groups. The groups included people with recurrent OBEs only, people with recurrent SBEs only, and those with a combination of the two binge-eating types. The authors also hypothesized that while there would be no difference in outcome with either type of binge-eating, those persons who had forms of combined SBE and OBE would have poorer outcomes than those with either binge-eating type alone.

The authors point out that the World Health Organization now recognizes the potential clinical significance of SBEs, and has removed the essential requirement for a binge to be large in the International Classification Diseases(ICD) for BEDs. In the proposed ICD-11criteria, a binge eating episode is defined as “a distinct period of time during which the individual experiences a subjective loss of control over eating, eating notably more or differently than usual, and feels unable to stop eating or limit the type or amount of food eaten.” The study used data collected in 2016 in the Health Omnibus Survey, which involved face-to-face interviews conducted annually in South Australia.

The study results

Dr. Li and colleagues found significant similarities between the OBE and SBE groups across all measures, which supported previous research indicating that SBE is associated with similar health consequences and eatng-related psychopathology as DSM-5 recognized OBEs.

One area the researchers assessed was the demographic profiles of the study groups. Participants from the SBE and OBE groups were similar in age, but those in the non-binge-eating group were an average 7 and 10 years older than those in the OBE and SBE groups, a finding that differed from earlier studies. Was this due to a smaller sample size in earlier studies or to the fact that binge eating may disproportionately affect younger persons? There was no marked effect by gender. Also, there were no significant differences by educational level attained, or quality of life.

As for body mass index, (BMI), no significant differences were shown between those in the OBE and SBE groups, which was surprising because the behaviors in the two groups differed based on the amount of food consumed. As expected, participants in the combined group were found to have significantly higher BMIs than participants who only reported one form of binge eating. People who endorsed both types of binge eating generally had the poorest outcomes in health-related measures such as BMI, quality of life, and overvaluation. The authors pondered whether those who reported both OBEs and SBEs (2.5% of the study participants) engaged in more frequent binge eating, a factor that warrants further study.

A final finding of note: gender differences in binge eating were not seen in this community sample. This argues that the typical gender disparity in those receiving eating disorders treatment is largely reflective of factors affecting case-finding and care seeking rather than true variation in prevalence.