Fasting increases risk for onset of binge eating and bulimic pathology: a 5-year prospective study.

Although adolescent girls with elevated dietary restraint scores are at increased risk for future binge eating and bulimic pathology, they do not eat less than those with lower restraint scores. The fact that only a small proportion of individuals with elevated dietary restraint scores develop bulimic pathology suggests that some extreme but rare form of dietary restriction may increase risk for this disturbance. The authors tested the hypothesis that fasting (going without eating for 24 hr for weight control) would be a more potent predictor of binge eating and bulimic pathology onset than dietary restraint scores using data from 496 adolescent girls followed over 5 years. Results confirmed that only 23% of participants with elevated dietary restraint scores reported fasting. Furthermore, fasting generally showed stronger and more consistent predictive relations to future onset of recurrent binge eating and threshold/subthreshold bulimia nervosa over 1- to 5-year follow-up relative to dietary restraint, though the former effects were only significantly stronger than the latter for some comparisons. Results provide preliminary support for the hypothesis that fasting is a stronger risk factor for bulimic pathology than is self-reported dieting.