['Activity-based anorexia is an animal model of anorexia nervosa in which limited access to standard lab chow combined with voluntary wheel running leads to hypophagia and severe weight loss. This study tested whether activity-based anorexia could be prevented or reversed with palatable foods.', 'Male rats were divided into sedentary or ad libitum-running groups and maintained on 1 h daily access to standard chow plus one of the following: sugar, saccharin, vegetable fat (shortening), or sweet high-fat chow.', 'Access to the sweet high-fat chow both reversed and prevented the weight loss typical of activity-based anorexia. Vegetable fat attenuated body weight loss, but to a lesser degree than the sweet high-fat diet. The addition of saccharin or sucrose solutions to the standard lab-chow diet had no effect.'] Does a high-fat diet prevent and reverses the development of activity-based anorexia in rats?