Identifying dieters who will develop an eating disorder: a prospective, population-based study.

OBJECTIVE The aims of the study were to identify the characteristics of the dieters most at risk of subsequently developing an eating disorder and to evaluate the feasibility of using a brief questionnaire to identify such dieters in advance. METHOD A general population cohort of 2,992 young women who were dieting was identified. On four occasions over the subsequent 2 years, this cohort was sent a questionnaire concerning eating habits and attitudes. Participants whose responses suggested that they had developed an eating disorder were interviewed to establish their true case status. The baseline questionnaires of those who did and did not subsequently develop an eating disorder were compared to identify features that predicted future case status. RESULTS One hundred four of the dieters developed an eating disorder of clinical severity during the 2 years of follow-up. Their baseline questionnaire scores differed in many respects from those who had not developed an eating disorder. Items associated with developing an eating disorder were selected by using three different statistical methods. A simple case-predicting instrument based on one of five items scoring above an optimal cut point had a sensitivity of 71% and a specificity of 72% (overall efficiency of 72%). CONCLUSIONS Dieters who will develop an eating disorder within the next 2 years have distinctive features. It is feasible to identify them in advance with reasonable efficiency with a brief questionnaire. This questionnaire could be incorporated into routine health assessments, thereby identifying those at high risk.