What Are Eating Disorders?

Importance: Eating disorders are characterized by disturbances in eating behavior and occur worldwide, with a lifetime prevalence of 2% to 5%. They are more common among females than males and may be associated with medical and psychiatric complications, impaired functioning, and decreased quality of life.

Observations: Common eating disorders include anorexia nervosa, bulimia nervosa, binge-eating disorder, and avoidant/restrictive food intake disorder. These disorders may be associated with changes in weight, electrolyte abnormalities (eg, hyponatremia, hypokalemia), bradycardia, disturbances in reproductive hormones (eg, decreased estradiol levels in females), and decreased bone density. Individuals with anorexia nervosa, bulimia nervosa, and binge-eating disorder have high lifetime rates of depression (76.3% for bulimia nervosa, 65.5% for binge-eating disorder, and 49.5% for anorexia nervosa) and higher rates of suicide attempts than those without eating disorders. Anorexia nervosa is associated with a mortality rate of 5.1 deaths per 1000 person-years (95% CI, 4.0-6.1), nearly 6 times higher than that of individuals of the same age without anorexia nervosa; 25% of deaths among individuals with anorexia nervosa are from suicide. First-line treatments for eating disorders include nutritional support, psychotherapy, and pharmacotherapy. Behaviorally focused therapies, including cognitive behavioral therapy, may be effective, especially for bulimia nervosa and binge-eating disorder. Youth with anorexia nervosa benefit from family-based treatment with parental oversight of eating, resulting in a remission rate at 6 to 12 months of 48.6% vs 34.3% with individual treatment (odds ratio, 2.08; 95% CI, 1.07-4.03; P = .03). Fluoxetine and other antidepressants decrease episodes of binge eating in individuals with bulimia nervosa, even in those without depression (fluoxetine vs placebo, standardized mean difference = -0.24 [small effect size; 95% CI, -0.41 to -0.08]). Antidepressants and the central nervous system stimulant lisdexamfetamine reduce binge frequency in binge-eating disorder compared with placebo (antidepressants vs placebo, standardized mean difference = -0.29 [small effect size; 95% CI, -0.51 to -0.06]; lisdexamfetamine vs placebo, Hedges g = 0.57 [medium effect size; 95% CI, 0.28-0.86]). There are currently no effective medications for treatment of anorexia nervosa. Individuals with serious medical or psychiatric complications of eating disorders such as bradycardia or suicidality should be hospitalized for treatment.

Conclusions and relevance: Globally, eating disorders affect 2% to 5% of individuals during their lifetime and are more common in females than males. In addition to weight changes, eating disorders may cause electrolyte abnormalities, bradycardia, disturbances in reproductive hormones, and decreased bone density, and are associated with increased risk of depression, anxiety, and suicide attempts. First-line treatments of eating disorders include nutritional support, psychotherapy, and pharmacotherapy.

Author/s:

Evelyn Attia, B Timothy Walsh