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Introduction to Eating Disorders

by Evelyn Attia, MD, B. Timothy Walsh, MD

Eating disorders involve a persistent disturbance of eating or of behavior related to eating that

  • Alters consumption or absorption of food

  • Significantly impairs physical health and/or psychosocial functioning

Specific eating disorders include

See the American Psychiatric Association’s Practice Guidelines: Treatment of Patients With Eating Disorders, 3rd Edition , its corresponding Guideline Watch (August 2012), and guidelines from the National Institute for Clinical Excellence [NICE] .

Avoidant/restrictive food intake disorder

In this disorder, patients avoid eating food or restrict their food intake to such an extent that they have ≥ 1 of the following:

  • Significant weight loss or, in children, failure to grow as expected

  • Significant nutritional deficiency

  • Dependence on enteral feeding (ie, via a feeding tube) or oral nutritional supplements

  • Markedly disturbed psychosocial functioning

Criteria for the disorder include that the food restriction is not caused by unavailability of food, a cultural practice (eg, religious fasting), physical illness, medical treatment (eg, radiation therapy, chemotherapy), or another eating disorder—particularly anorexia nervosa or bulimia nervosa—and that there is no evidence of a disturbed perception of body weight or shape. However, patients who have a physical disorder that causes decreased food intake but who maintain the decreased intake for much longer than typically expected and to a degree requiring specific intervention may be considered to have avoidant/restrictive food intake disorder.

Avoidant/restrictive food intake disorder typically begins during childhood and may initially resemble the picky eating that is common during childhood—when children refuse to eat certain foods or foods of a certain color, consistency, or odor. However, such food fussiness, unlike avoidant/restrictive food intake disorder, usually involves only a few food items, and the child's appetite, overall food intake, and growth and development are normal. In avoidant/restrictive food intake disorder, nutritional deficiencies can be life threatening, and social functioning (eg, participating in family meals) can be markedly impaired.

When patients first present, clinicians must exclude physical illness as well as other mental disorders that impair appetite and/or intake, including other eating disorders, depression, schizophrenia, and factitious disorder imposed on another.

Behavioral therapy is commonly used to help patients normalize their eating.


Pica is persistent eating of nonnutritive, nonfood material for ≥ 1 mo when it is not developmentally appropriate (eg, in children < 2 yr, who frequently mouth and ingest a variety of objects) nor part of a cultural tradition (eg, of folk medicine, religious rites, or common practice, such as ingestion of clay (kaolin) in the Georgia Piedmont). Patients tend to eat nontoxic materials (eg, paper, clay, dirt, hair, chalk, string, wool), and usually ingestion does not cause significant medical harm. However, some patients develop complications such as GI obstruction by impacted material, lead poisoning from eating paint chips, and parasitic infestation from eating dirt.

Pica itself rarely impairs social functioning, but it often occurs in people with other mental disorders that do impair functioning (eg, autism, intellectual disability, schizophrenia). Pica is also common during pregnancy. Swallowing objects in an attempt to cause self-harm or to falsify illness (see Factitious Disorder Imposed on Self) is not considered pica.

Rumination disorder

In rumination disorder, patients repeatedly regurgitate food after eating, but they have no nausea or involuntary retching. The food may be spit out or reswallowed; some patients rechew the food before reswallowing. The behavior must occur over a period of ≥ 1 mo and must not be caused by a GI disorder that can lead to regurgitation (eg, gastroesophageal reflux, Zenker diverticulum) or by another eating disorder such as anorexia nervosa. Regurgitation occurs several times a week, typically daily.

The regurgitation is volitional (although patients may report not being able to restrain themselves) and often can be directly observed by the clinician. Some patients are aware that the behavior is socially undesirable and attempt to disguise it by putting a hand over their mouth or limiting their food intake. Patients who spit out the regurgitated material or who significantly limit their intake may lose weight or develop nutritional deficiencies.

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