Although “disordered eating,” as a set of psychiatric conditions, implicitly evaluates components of a social phenomenon, little attention has been paid to the boundaries between socially accepted and abnormal eating. Lay knowledge and evaluations of the formal criteria for a diagnosis of anorexia nervosa or bulimia were therefore examined. The results show that although males and females know more about anorexia nervosa than bulimia, the DSM‐III criteria for anorexia nervosa, which involve the determined pursuit of slimness and a body image disturbance, were judged by very few people to be both uncommon and abnormal. Bulimia, however, seems to be much closer to what is commonly judged to involve unusual behavior.