 The heart rate variability HRV is a measure of the autonomic nervous system ANS. In the model of anorexia nervosa, ANS is disturbed with mostly a predominance of activation of the parasympathetic nervous system and a decrease of the sympathetic system. Various explanations of this these dysfunctions are proposed in literature, mainly malnutrition, physical hyperactivity, anxiety, that are known characteristics of anorexia nervosa. 