Responses to bright light exposure in individuals with binge-spectrum eating disorders characterized by high dietary restraint and negative affect.

OBJECTIVE

Circadian rhythm disruptions are associated with binge eating, can be causal of negative mood, and may be corrected with bright light exposure. A subtype of individuals with binge-spectrum eating disorders are characterized by combined high dietary restraint and negative affect. These individuals have higher eating disorder psychopathology and poorer treatment response. We aimed to test the targeted effects of morning bright light exposure on individuals with binge-spectrum eating disorders, hypothesizing significant reductions in binge eating for those characterized by high dietary restraint and negative affect.

METHODS

Participants (N = 34 females with binge-eating disorder and bulimia nervosa) used a morning bright light and normal light for 10 consecutive days each, in randomized order. They completed the Change in Eating Disorder Symptoms (CHEDS) scale at baseline, day 12 (when they switched lamps), and day 22. We conducted moderation analyses, clustering data by person, controlling for order, and examining the effect of light condition on binge eating according to baseline restraint and negative affect.

RESULTS

At high levels of combined dietary restraint and negative affect, participants experienced a reduction in binge eating and food preoccupation following exposure to morning bright light. There were no changes in restrictive eating, body preoccupation, body dissatisfaction, or body checking following exposure to morning bright light for these individuals.

DISCUSSION

These findings suggest that morning bright light may be a useful adjunct to empirically supported eating disorder treatments that target binge eating, especially for individuals characterized by the difficult to treat restraint/negative affect subtype.

PUBLIC SIGNIFICANCE

At high levels of combined dietary restraint and negative affect, participants with binge-spectrum eating disorders experienced a reduction in binge eating and food preoccupation following exposure to morning bright light. These findings suggest that morning bright light may be a useful adjunct to empirically supported eating disorder treatments that target binge eating, especially for individuals characterized by the difficult-to-treat restraint/negative affect subtype.