Restrictive eating disorder with severe weight loss and amenorrhoea

What it is

Anorexia nervosa is diagnosed when a person induces weight loss leading to a body weight of less than 85% of a healthy norm, or refuses to gain appropriate weight when growing taller; has an intense fear of gaining weight or becoming fat even though underweight; has a disturbance in the perception of his or her body shape; and, in women, has missed three consecutive menstrual cycles.

The DSM-5 criteria put the same disorder in three parts: 1) part 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, which means a weight less than minimally normal or, for children and adolescents, less than that minimally expected; 2) part B, intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight; 3) part C, disturbance in the way 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 current low body weight.

The DSM-5 criteria also set severity by body mass index: mild is a BMI of 17 kg/m2 or above, moderate 16-17 kg/m2, severe 15-16 kg/m2 and extreme under 15 kg/m2. It also names two states of remission: in partial remission, after full criteria for anorexia nervosa were met, criterion A has not been met for some time but criterion B or C is still met; in full remission, after full criteria were met, none of the criteria have been met for a sustained period of time.

The two accounts do not agree on the menstrual cycles: the loss of three consecutive cycles is a criterion in one and does not appear in the DSM-5 list in the other. A third reading sets the menstrual status out as amenorrhea common but not required.