The effect of psychiatric disorders on weight loss in obesity clinic patients

Research on psychiatric disorders in obesity has indicated that obese people are not psychiatrically different from nonobese people. Few studies, however, have addressed the potential impact of psychopathology on weight control. In the present study, a consecutive sample of 37 patients presenting to a major metropolitan weight control unit were given structured diagnostic interviews (Structured Clinical Interviews for Diagnosis I and II). These patients completed one of two 12-week diet programs involving either behavior modification or liquid protein diets. After 12 weeks of a liquid protein formula diet, patients with no personality disorder lost significantly more weight than personality disordered patients; personality disordered patients on a behavioral diet tended (p < .15) to lose more weight during a 12-week diet than the patients without personality disorders. These data suggest that there are differential responses to liquid protein and behavioral diets, depending on the presence or absence of a personality disorder.