This investigation is a prospective study of the development and course of nutrition-related problems in a normal adolescent population. The tong-term objective is to identify risk factors for the later development of eating disorders such as anorexia nervosa and bulimia or milder forms of these disturbances. Differences between those with transient maladaptive eating and mood patterns and those who develop a stable eating disorder will be examined. Groups of male and female adolescents will be followed from seventh through twelfth grade and assessed on an individual basis. A specific aim is to identify before the acute expression of an eating disorder particular combinations of psychological and food related factors that are linked to the later development of a disorder. Sex differences in the eventual expression of eating disturbances will be evaluated as well. Attitudes about sexuality, personality, and autonomy, perceived social support, depression, stress reactivity, and food and other substance consumption patterns will be studied through measures incorporated into two questionnaire booklets. Family processes will be measured through inventories completed in the home by a high risk and matched comparison subset of adolescents and their parents. The subset parents will be administered a diagnostic structured interview to assess the presence in the parents and other siblings of mood, substance abuse, or eating disorders. Subjects will be tested on a yearly basis. A preliminary study demonstrated a substantial prevalence of dieting, weight, and body preoccupations, and poor nutritional practices in a ninth grade population. The longitudinal design of the proposed project will enable one to identify psychological and behavioral risk factors before they are distorted by the presence of an acute problem. A long range benefit of this study is the eventual possibility of developing school-based prevention programs aimed at modifying the risk factors for eating disturbances identified in this investigation.