What is Anorexia Nervosa?

Anorexia Nervosa (AN) is a potentially fatal, highly heritable, neuro-behavioral illness characterized by restriction of food intake, weight loss, and inability to perceive one’s body size and shape accurately. Many individuals with AN have an extreme fear of eating and weight. AN may lead to a variety of severe medical and psychiatric consequences, including cardiac complications, osteoporosis, hypothermia, depression, obsessive-compulsive behaviors, amenorrhea, kidney failure, infertility, and suicide. Scientific research has demonstrated that the risk of developing AN is largely genetic. Other variables, such as puberty, temperament, and experience, also play a role in the manifestation of this illness. For those who are predisposed to AN, an energy deficit (consuming fewer calories than the body requires to meet energy needs) caused by dieting, illness, stress, athletic training, or a simple decision to “eat healthy,” triggers a self-perpetuating cycle of decreased food intake and weight loss. Once AN is set into motion, it becomes extremely difficult for the person to break free from this cycle without significant support. AN has the highest mortality rate of any psychiatric disorder.

Although the disorder typically begins in adolescence, AN occurs in people of all genders, all ages, and all shapes and sizes. It is not possible to tell if someone has AN simply by looking at them. While many people with AN have a thin or “underweight” appearance, others appear to be “normal weight” or even “overweight.” In fact, recent research indicates that nearly 1/3 of individuals who are hospitalized for AN are not underweight. Further, given that nutritional and physical recovery usually precede psychological recovery, people who are recovering from AN may appear to be “healthy” and “normal” based on their body size, while still suffering tremendously from food anxiety, body dysmorphia, depression, or other mental symptoms.