Anorexia nervosa (AN) is associated with a paradoxical reduction in hunger ratings following 2-deoxy-D-glucose (2DG) induced glucose insufficiency. Because of the relationship between exercise and AN, there is interest in the weight-loss phenomenon produced by exercise in food restricted rats. This investigation determined if the weight-loss phenomenon is associated with a paradoxical suppression of food intake following 2DG and if the effect is related to reductions in prevailing glucose and insulin levels. Weight-matched, normal-weight exercised and normal-weight unexercised rats served as controls. As predicted, 2DG reduced food intake in animals subjected to the phenomenon (1.5 h/day food access and 22.5 h/day running wheel access). This effect was related to reductions in plasma glucose and insulin under the conditions that prevailed at the time of injection. Since these changes also occurred in weight-matched controls, they were attributed to the general effects of weight loss. A situational specificity for the "anorexia" of the weight-loss syndrome was also demonstrated. Finally, the strengths and weaknesses of the phenomenon as a model of AN were considered.