Anorexia nervosa is an eating disorder characterized by weight loss (or lack of appropriate weight gain in growing children); difficulties maintaining an appropriate body weight for height, age, and stature.  Individuals with anorexia nervosa have an unhealthy desire for thinness. 

People with anorexia generally restrict the number of calories and the types of food they eat. Some people with the disorder also exercise compulsively, purge via vomiting and laxatives, and/or binge eat. 

In anorexia nervosa’s cycle of self-starvation, the body is denied the essential nutrients it needs to function normally.  Thus, the body is forced to slow down all of its processes to conserve energy, resulting in serious medical consequences.

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Atypical Anorexia

Atypical anorexia nervosa patients may not meet the criteria for being “underweight” but have experienced rapid weight loss.  This leads to the same life-threatening medical consequences as seen in Anorexia Nervosa. 

Multiple studies have found that atypical anorexia is at least two or three times more common than anorexia. An estimated 25-40 percent of patients seeking inpatient eating disorder treatment have a diagnosis of atypical anorexia.

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Avoidant Restrictive Food Intake Disorder (ARFID)

ARFID was formerly called Selective Eating Disorder. ARFID is similar to anorexia in that both disorders involve limitations in the amount and/or types of food consumed, but unlike anorexia, ARFID does not involve any distress about body shape or size, or fears of fatness. Although many children go through phases of picky or selective eating, a person with ARFID does not consume enough calories to grow and develop properly and, in adults, to maintain basic body function. 

As with all eating disorders, the risk factors for ARFID involve a range of biological, psychological, and sociocultural issues. These factors may interact differently in different people, which means two people with the same eating disorder can have very diverse perspectives, experiences, and symptoms. Researchers know much less about what puts someone at risk of developing ARFID, but here’s what they do know:

• People with autism spectrum conditions are much more likely to develop ARFID, as are those with ADHD and intellectual disabilities.
• Children who don’t outgrow normal picky eating, or in whom picky eating is severe, appear to be more likely to develop ARFID.
• Many children with ARFID also have a co-occurring anxiety disorder, and they are also at high risk for other psychiatric disorders.