1980). However, two recent studies have indicated that there are characteristics which distinguish anorexia patients who develop bulimia from those who do not (Casper et al., 1980; Garfinkel et al., 1980). These authors suggested that the presence of bulimia constitutes a distinct subgroup, not just an'end-stage'of chronic anorexianervosa. Indeed cases have been described of bulimia, combined with a morbid fear of fatness, occurring without any history of anorexia (Russell, 1979; Fairburn, 1980).

Furthermore it is now evident that binge eating and vomiting behaviour occur in normal weight and even ovcrweight people and this has led to the classification of bulimia as a disorder distinct from anorexia nervosa in the 3rd edition of the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM-III, 1980). Moreover a recent survey of a college population has suggested a prevalence for bulimia of 13%, indicating that binge eating may represent a very serious and growing public health problem (Halmi et al., 1981).