Anorexia in response to acute illness.

Anorexia associated with acute illness remains one of the most common, challenging, and difficult symptoms to treat. Surprisingly, little attention has been devoted to development of interventions to reverse this form of anorexia. Although incomplete, current understanding of the mechanisms responsible for illness-induced anorexia is sufficient to suggest therapeutic approaches. In this article, the major physiologic mechanisms underlying illness-induced anorexia are described. In addition, potential moderating effects of social, psychologic, and environmental factors are discussed. This information was used to develop recommendations for the treatment of anorexia. A majority of these interventions, however, are not research based. Further advances in the treatment of illness-induced anorexia will require greater understanding of the complex, interactive effects of psychologic, environmental, and biologic factors on eating behavior during illness. Therefore, areas requiring continued investigation are also outlined.