A 21-year-old woman presents to the clinic with her parents because they are concerned that she appears thin. They have noticed that she pretends to eat her food during dinner, but she secretly places the food in a napkin to throw it away when nobody is looking. When questioned, she mentions that she has not had a menstrual period in the past 2 years. When asked about her body weight, she patient says she feels "fat" and would love to lose 20 more pounds in order to look like the models in magazines. On physical examination, the patient has a BMI of 17. She has soft, fine hair over her abdomen and extremities, and her conjunctiva are pale.
B) Anorexia nervosa with predominantly restricting behaviors
From the stem, the patient appears to have anorexia nervosa with predominantly restricting behaviors. One way in which she is restricting her food intake is by hiding food during meals and then throwing it away when nobody is looking. In addition to her restrictive behaviors, the patient has a BMI of <18.5 and lanugo over her abdomen and extremities. Anemia is suggested by the pale conjunctiva, and she has had amenorrhea for the past 2 years. Another clue that the patient is anorexic is that the patient believes she is "fat," desiring to lose 20 pounds despite clear evidence to the contrary.
Anorexia nervosa with predominantly purging behaviors would show the patient restricting food intake in addition to engaging in compensatory mechanisms for eating, such as excessive exercising.
Binge eating disorder is characterized by excessive, uncontrollable eating without compensatory mechanisms.
Bulimia nervosa is characterized by binge eating in combination with compensatory mechanisms to make up for the binge eating, such as vomiting, laxative use, and excessive exercising. Patients with bulimia nervosa typically have BMIs within the normal range.
Key Learning Point
The diagnosis of anorexia nervosa requires 1) restriction of energy intake that leads to a low body weight, 2) intense fear of gaining weight or becoming fat, or persistent behavior that prevents weight gain, despite being underweight, and 3) distorted perception of body weight and shape, undue influence of weight and shape on self-worth, or denial of the medical seriousness of one’s low body weight. Amenorrhea is common in anorexia nervosa but is not a diagnostic criterion.
