There are eight recognized eating disorders in the current diagnostic manual used by mental health professionals. The three most widely known are anorexia nervosa, bulimia nervosa, and binge-eating disorder, but the full spectrum includes conditions that look very different from one another, ranging from extreme food restriction to eating non-food substances. Eating disorders carry the second highest mortality rate of any psychiatric illness, behind only opiate addiction, so understanding what each one involves matters.
Anorexia Nervosa
Anorexia nervosa is a pattern of self-starvation involving significant weight loss, typically 15 percent or more of a person’s ideal body weight. The core psychological feature is an intense fear of gaining weight paired with a distorted perception of one’s own body size or shape. Someone with anorexia may see themselves as overweight even when they are dangerously underweight.
There are two subtypes. In the restricting type, weight loss happens through dieting, fasting, or excessive exercise. People with this subtype tend to be perfectionistic, eager to please others, sensitive to criticism, and resistant to changes in routine. In the binge-eating/purging type, the person also engages in episodes of binge eating or purging (self-induced vomiting, laxative misuse, or similar behaviors), but their body weight remains significantly low. When someone is underweight and also bingeing and purging, the anorexia diagnosis takes priority over a bulimia diagnosis.
The medical consequences are severe. Starvation disrupts the balance of electrolytes like sodium, potassium, and calcium, which can cause fatal heart arrhythmias. Long-term restriction leads to bone loss (osteoporosis), heart valve problems, and heart failure. Even the digestive system slows down dramatically, causing early fullness and constipation, which ironically increases preoccupation with food and raises the risk of eventually developing binge-eating behavior.
Bulimia Nervosa
Bulimia nervosa shares the same overvalued drive for thinness and dissatisfaction with body shape that characterizes anorexia, but the person’s weight is usually within or above the normal range. The defining cycle is binge eating followed by compensatory behaviors meant to prevent weight gain: self-induced vomiting, laxative or diuretic misuse, fasting, or excessive exercise. These binges and compensatory behaviors occur at least once a week.
A binge in this context isn’t just overeating at a holiday meal. It involves consuming an unusually large amount of food in a short period while feeling a loss of control. The compensatory behaviors that follow are driven by guilt, shame, and fear of weight gain. Severity is measured by how often these compensatory episodes happen, ranging from mild (one to three times per week) to extreme (14 or more times per week). Repeated vomiting erodes tooth enamel, damages the esophagus, and creates the same dangerous electrolyte imbalances seen in anorexia.
Binge-Eating Disorder
Binge-eating disorder (BED) is the most common eating disorder in the United States. It involves the same pattern of consuming large amounts of food with a feeling of lost control, but unlike bulimia, people with BED do not throw up afterward, misuse laxatives, or exercise compulsively to compensate. That absence of compensatory behavior is the key distinction.
People with BED often eat when they’re not hungry, eat until they feel uncomfortably full, eat rapidly, and eat alone because they feel embarrassed about how much they’re consuming. The episodes are followed by significant distress, guilt, or disgust. Over time, BED frequently leads to weight gain and the health problems associated with it, but the disorder affects people across all body sizes.
Avoidant/Restrictive Food Intake Disorder (ARFID)
ARFID involves avoiding certain foods or entire categories of food, having a severely restricted overall intake, or both. What separates it from anorexia is that ARFID has nothing to do with body image. There is no fear of gaining weight and no distorted self-perception of body size. Instead, the avoidance is driven by things like extreme sensitivity to food textures, tastes, or smells, a fear of choking or vomiting, or simply a profound lack of interest in eating.
ARFID can lead to significant nutritional deficiencies, weight loss, and dependence on nutritional supplements. It’s more commonly diagnosed in children, but it occurs in adults too, and it goes well beyond “picky eating.” The restriction is severe enough to interfere with growth, nutrition, or daily functioning.
Pica
Pica is the persistent eating of non-food substances that have no nutritional value, such as paper, clay, dirt, hair, chalk, string, or soap. To qualify as a disorder, this behavior needs to be ongoing and inappropriate for the person’s developmental stage (young toddlers who mouth everything don’t meet the criteria). Pica occurs across all ages and is more common in people with intellectual disabilities and during pregnancy. The main medical risks are poisoning, intestinal blockages, and infections depending on the substances consumed.
Rumination Disorder
Rumination disorder involves repeatedly regurgitating food after eating. The regurgitated food may be re-chewed, re-swallowed, or spit out. This happens several times per week, typically daily, and must persist for at least one month. The regurgitation isn’t caused by nausea or an involuntary gag reflex, and it isn’t explained by another medical condition like acid reflux. Rumination disorder can occur at any age but is most commonly identified in infants and in people with developmental disabilities. In adults, it often goes undiagnosed because people are reluctant to describe the behavior.
Other Specified Feeding or Eating Disorder (OSFED)
OSFED is a category for people who have clinically significant eating disorder symptoms but don’t meet all the criteria for one of the conditions above. This is not a “mild” category. OSFED is just as dangerous and distressing as any other eating disorder, and it’s actually one of the most commonly diagnosed.
It includes five recognized subtypes. Atypical anorexia nervosa describes someone who meets all the criteria for anorexia, including the restriction and the psychological features, but whose weight remains in or above the normal range. Sub-threshold bulimia nervosa and sub-threshold binge-eating disorder describe people whose binge or purge episodes happen less frequently or for a shorter duration than the full diagnostic criteria require. Purging disorder involves purging to control weight without binge-eating episodes. Night eating syndrome involves recurrent episodes of eating after waking from sleep or consuming a large portion of daily calories after the evening meal.
How These Disorders Overlap
Eating disorders frequently share features. An overvalued drive for thinness and dissatisfaction with body shape runs through anorexia and bulimia alike. People can also move between diagnoses over the course of their illness. Someone who starts with anorexia’s restricting subtype may develop binge-eating behavior as their body responds to prolonged starvation, and the diagnosis may shift accordingly.
Globally, an estimated 0.23 percent of the population has anorexia or bulimia in any given year, based on modeling from the Global Burden of Disease project. That figure doesn’t capture binge-eating disorder, ARFID, or OSFED, so the true number of people living with an eating disorder is substantially higher. These conditions affect people of every gender, age, ethnicity, and body size, though they remain underdiagnosed in groups that don’t fit the stereotype of a young, thin, white woman.