Eveningness and bulimic behavior

Previous research suggests that evening constitutes a high-risk environment that increases the probability of binge eating and purging. Individual differences in morningness-eveningness are associated with differing levels of exposure to evening, versus day, with night people spending a larger portion of their waking lives during the evening and a smaller portion of their waking lives during the day than do day people. This study tested the hypothesis that greater eveningness is associated with greater binging and purging. One-hundred and fifty-one undergraduates completed the Composite Scale of Morningness-Eveningness, the Bulimia Test-Revised, the Bulimia Scale of the Eating Disorders Inventory, and measures of several other variables. Results showed that eveningness was correlated, moderately and positively (rs = 0.24) with both measures of bulimic behavior; these correlations were reduced only slightly after controlling for other study variables. It is argued that exposure to the dimmer lighting of evening promotes general behavioral disinhibition, thus undermining self-regulatory control and adherence to one's dietary standards, resulting in the disinhibited eating that is the hallmark of bulimia. (C) 2001 Elsevier Science Ltd. All rights reserved.