Eating disorders, particularly anorexia nervosa, are not just characterized by body image disturbance and weight loss. Eating disorders have a full spectrum of diagnostic criteria and signs and symptoms that affect every body shape and size. Although the medical definition of anorexia nervosa does include a classification related to the failure to gain weight, eating disorder treatment experts agree that not all individuals with anorexia nervosa are considered to be underweight. The anorexia medical definition characterizes this eating disorder by the intense fear of gaining weight, a distorted body image, inability to maintain a minimally normal weight and extreme dietary habits that prevent weight gain. There are two subtypes of anorexia nervosa known as the restricting type and the binge-eating/purging type. Most individuals associate anorexia with the restricting subtype, which is characterized by the severe limitation of food as the primary means to lose weight. The second subtype is known as binge-eating/purging subtype which is characterized by periods of binging followed by self-induced purging behaviors such as vomiting, diuretic abuse, laxative abuse or excessive exercise.

Definition of atypical anorexia

Atypical anorexia (AAN) was added to the Diagnostic and Statistical Manual-5 as a type of Other Specified Feeding and Eating Disorder (OSFED) in 2013. It is diagnosed when an individual meets all of the criteria for anorexia nervosa, except that despite significant weight loss, the individual’s weight is within or above the normal range. An individual with atypical anorexia nervosa still meets the other criteria for anorexia nervosa (AN): fear of gaining weight or becoming fat, body image disturbance, and presenting with significant weight loss. Significant weight loss can still occur without being underweight if these individuals started in a higher weight category. However, based on their trajectory of weight loss and restrictive behaviors, they are actually in a state of malnourishment.

Why weight categories do not matter in anorexia nervosa

Significant weight loss lacks a widely accepted definition. Research suggests that when combined with the intense fear of weight gain or fat and considerable body image disturbance experiences, as little as a 5 percent weight loss may indicate clinically significant eating pathology, qualifying the patient as having a diagnosis of atypical anorexia nervosa. An older definition of anorexia nervosa that is no longer accepted stated that individuals with anorexia nervosa were characterized by weighing less than 85% of their ideal body weight and having missed at least three consecutive menstrual periods. The inclusion of having a weight 15 percent below the individual’s ideal body weight was eliminated from today’s current anorexia nervosa medical definition. Experts are realizing being underweight, “normal” weight or overweight does not determine whether an individual is malnourished or is engaging in unhealthy behaviors that lead to weight loss.

Medical complications associated with anorexia nervosa

Regardless of whether an individual is diagnosed with anorexia nervosa or atypical anorexia nervosa, according to their body type; they are at high risk of developing physical medical complications that affect nearly every organ system in the body.

  • Decreased intestinal and gastric mobility
  • Constipation
  • Delayed gastric emptying
  • Gastric dilation and rupture
  • Esophageal tears
  • Fine body hair (lanugo)
  • Hair loss
  • Dry skin
  • Dental cavities (secondary to self-induced vomiting)
  • Delayed puberty (secondary to estrogen deficiency)
  • Stunted growth
  • Osteoporosis (secondary to estrogen deficiency)
  • Amenorrhea (loss of menstrual cycles secondary to estrogen deficiency)
  • Infertility
  • Anemia
  • Refeeding syndrome
  • Cardiovascular collapse
  • Cardiovascular arrhythmias
  • Dehydration
  • Electrolyte disturbances
  • Other Complications