Anorexia nervosa (AN) is an eating disorder leading to malnutrition and, ultimately, to energy wasting and cachexia. Rodents develop activity-based anorexia (ABA) when simultaneously exposed to a restricted feeding schedule and allowed free access to running wheels. These conditions lead to a life-threatening reduction in body weight, resembling AN in human patients. Here, we investigate the effect of ABA on whole body energy homeostasis at different housing temperatures.

Anorexia nervosa (AN) is a severe psychiatric condition primarily affecting young women, and AN has the highest mortality rate among psychiatric disorders. AN continues to be a disorder refractory to psychological or pharmacological treatment. An innovative approach arises from research in rats simultaneously placed on a restricted feeding schedule and given free access to an activity wheel. The detrimental effects of combining diet and exercise in rats can be reversed by a manipulation of ambient temperature (AT).

The case for warming as an adjunctive treatment for AN patients is based on strong experimental evidence gathered from research on animals with Activity-Based Anorexia (ABA). We posit that the beneficial effect of heat results, at least in part, from heat blocking the vicious cycle that hyperactivity plays on AN. Hyperactivity decreases caloric intake by interfering with feeding and increases energy expenditure through excess motor activity which in turn increases emaciation that further strengthens anorexic thinking.  

Disparate treatments, placebos, and treatments as usual have similar efficacy for anorexia nervosa. A parsimonious dissection of the this issue with Occam’s razor will necessarily challenge the assumptions on which the diagnosis of anorexia nervosa is based. One such assumption is the role of body-image disturbance, which became a key diagnostic symptom of anorexia nervosa in the literature almost five decades ago, long before any empirical evidence was gathered about this symptom.