Definition Bulimia nervosa is an intense preoccupation with body weight and shape, with regular episodes of uncontrolled overeating of large amounts of food (binge eating) associated with use of extreme methods to counteract the feared effects of overeating. If a person also meets the diagnostic criteria for anorexia nervosa, then the diagnosis of anorexia nervosa takes precedence.1 Bulimia nervosa can be difficult to identify because of extreme secrecy about binge eating and purgative behaviour. Weight may be normal but there is often a history of anorexia nervosa or restrictive dieting. Some people alternate between anorexia nervosa and bulimia nervosa.

Incidence/prevalence In community based studies, the prevalence of bulimia nervosa is between 0.5% and 1.0%, with an even social class distribution.2-4 About 90% of people diagnosed with bulimia nervosa are women. The numbers presenting with bulimia nervosa in industrialised countries increased during the decade that followed its recognition in the late 1970s and “a cohort effect” is reported in community surveys, 2 5 6 implying an increase in incidence. The prevalence of eating disorders such as bulimia nervosa is lower in non-industrialised populations7 and varies across ethnic groups. African-American women have a lower rate of restrictive dieting than white American women but have a similar rate of recurrent binge eating.8

Aetiology/risk factors Young women from the developed world who restrict their dietary intake are at highest risk of developing bulimia nervosa and other eating disorders. One community based case control study compared 102 people with bulimia nervosa with 204 healthy controls and found that people with the eating disorder had higher …