Eating disorders: a situation of malnutrition with peculiar changes in the immune system.

Eating disorders, such as anorexia nervosa and bulimia nervosa, are significant public health concerns for a great deal of the population, and thus are even considered to be epidemics. These syndromes have a common aim: the pursuit of a desirable and extremely low weight, which is obviously very far from the ideal body weight. Therefore, these patients show abnormal food behavior, leading to a situation of malnutrition. Nutrients play an important role in the development and functionality of the immune system. Thus, the assessment of immunological parameters acquires great interest as a useful tool to evaluate the nutritional status of these patients. In addition, it is very well known that a depleted immune system as a consequence of malnutrition is linked to an increased susceptibility to infections. However, an extensive literature has pointed out that anorexic patients, even though severely malnourished, are relatively free from infectious diseases. As the immune system is altered by distorted food behaviors, such as in case of eating disorders, the awareness of the characteristics of other systems involved in these pathologies, and therefore altered, would be very helpful for the understanding of the mechanisms triggered in these syndromes. In fact, the interactions among the immune system and the remaining systems in eating disorders are beginning to be studied. Finally, the main goal is to limit the evolution of these illnesses through an early diagnosis and appropriate therapy to subsequently get a constant and definitive cure for the patients.