The symptoms of anorexia nervosa include abnormally low body weight, intense fears of weight gain, and distorted perception of body weight. The 12-month prevalence of anorexia nervosa among young females is approximately 0.4%. Clinical populations generally reflect a 10:1 female-to-male ratio.
A. Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as weight that is less than minimally normal or, for children and adolescents, less than the minimally expected. As are reference, a BMI of 18.5kg/m2 in adults has been employed by the Centers for Disease Control and prevention (CDC) and World Health Organization (WHO) as the lower limit of normal body weight.
B. Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.
C. Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.