According to the American Psychiatric Association–

“Eating disorders are behavioral conditions characterized by severe and persistent disturbance in eating behaviors and associated distressing thoughts and emotions. They can be severe conditions affecting physical, psychological, and social function. Types of eating disorders include anorexia nervosa, bulimia nervosa, binge eating disorder, avoidant restrictive food intake disorder, other specified feeding and eating disorder, pica, and rumination disorder.”

The DSM5 classifies eating disorders in the following categories:

Anorexia Nervosa

Anorexia nervosa is characterized by self-starvation and weight loss, resulting in low weight for height and age. Body mass index or BMI, a measure of weight for height, is typically under 18.5 in an adult individual with anorexia nervosa. Anorexia has the highest mortality of any psychiatric diagnosis other than opioid use disorder and can be a severe condition.

Dieting behavior in anorexia nervosa is driven by an intense fear of gaining weight or becoming fat. Although some individuals with anorexia will say they want and are trying to gain weight, their behavior is inconsistent with this intent. For example, they may only eat small amounts of low-calorie foods and exercise excessively. Some persons with anorexia nervosa also intermittently binge eat or purge by vomiting or laxative misuse.

There are two subtypes of anorexia nervosa:

• restricting type, in which individuals lose weight primarily by dieting, fasting, or excessively exercising, and
• Binge-eating/purging is when people also engage in intermittent binge eating and/or purging behaviors.

Over time, some of the following symptoms may develop related to starvation or purging behaviors:

• Menstrual periods cease
• Dizziness or fainting from dehydration
• Brittle hair/nails
• Cold intolerance
• muscle weakness and wasting
• Heartburn and reflux (in those who vomit)
• Severe constipation, bloating, and fullness after meals
• Stress fractures from compulsive exercise as well as bone loss resulting in osteopenia or osteoporosis (thinning of the bones)
• Depression, irritability, anxiety, poor concentration, and fatigue

Serious medical complications can be life-threatening and include heart rhythm abnormalities, especially in those patients who vomit or use laxatives, kidney problems, or seizures.

Treatment for anorexia nervosa involves helping those affected normalize their eating and weight control behaviors and restore their weight. The nutritional plan should help individuals counter anxiety about eating and consuming a broad, balanced range of foods with varying calorie densities across regularly spaced meals. For adolescents, the most effective treatment involves training parents to support and monitor their child’s meals. Addressing body dissatisfaction is also essential, but this often takes longer to correct than weight and eating behavior. Medical evaluation and treatment of any co-occurring psychiatric or medical conditions are crucial components of the treatment plan.

In the case of severe anorexia nervosa, when outpatient treatment is not practical, admission to an inpatient or residential behavioral specialty program may be indicated. Most specialty programs are effective in restoring weight and normalizing eating behavior, although ongoing issues are expected in the first year. Relapse in the first year following program discharge remains significant.