Preoccupation, food, and failure: An investigation of cognitive performance deficits in dieters

Objective: This study tested two explanations of the cognitive performance deficits of dieters. First, these deficits are due to the metabolic consequences of food deprivation. Second, they are psychological in origin (i.e., preoccupation with dieting-related thoughts during dieting depletes the cognitive resources available for nondieting tasks). Method: Dieters and nondieters performed a battery of cognitive tasks before and after consumption of a high-energy chocolate bar. Eating the chocolate bar was expected to reverse the effects of food deprivation but, as a diet-threatening food, it could increase dieting-related preoccupation. Results and Conclusions: The results supported the latter prediction. Performance on a memory task was further impaired, rather than improved, after food consumption in dieters. In addition, dieters experienced a significant increase in the number of food and dieting-related thoughts. Some dieters attributed their poorer performance to distraction by these thoughts. Marked individual differences in thought content accounted for some of the variability in the effects on performance. (C) 2003 by Wiley Periodicals, Inc.