The Classification of Feeding or Eating Disorders in the ICD-11

Eating disorders (EDs), described in the 11th edition of the International Classification of Diseases, ICD-11, the subject of this chapter, are severe conditions that occur across age and gender with prevalence rates as high as 16.3% in some countries (Dahlgren et al., 2019). These conditions are often chronic, have a major impact on overall health, and are associated with elevated suicide risk and mortality (Arcelus et al. Arch General Psychiatry 68(7):724–731, 2011; Dickstein et al. Cleve Clin J Med 81(4):255–263, 2014; Eaton et al. MMWR Surveill Summ 57(4):1e131, 2008; Udo et al. Biol Psychiatry 84:345–354, 2019; Zerwas et al. J Psychiatry Res 65:16–22, 2015). Among the specifically described eating disorders, Binge Eating Disorder (BED) and Bulimia Nervosa (BN) are more common than Anorexia Nervosa (AN); however, AN is the ED that carries the highest mortality rate (Dahlgren et al., 2019; Zerwas et al. J Psychiatry Res 65:16–22, 2015). Eating disturbances that do not conform to the specifically described diagnoses of AN, BN, or BED, and those that are considered subthreshold with respect to the established ED diagnoses, have the highest prevalence and convey significant disease burden, adverse health outcomes, and service use (Thomas et al. Psychol Bull 135(3):407–433, 2009). Less data is available on the epidemiology, etiology, natural course, and prognosis of other Feeding and Eating Disorders (FEDs), but over the course of the past decade, our knowledge base has grown substantially. For example, epidemiological data indicate that Avoidant-Restrictive Food Intake Disorder (ARFID) may affect as many as 13.8% of children and adolescents who seek treatment for eating disturbances (Fisher et al. J Adolesc Health 55(1):49–52, 2014), 8.4% of pediatric inpatients (Cooney et al. J Eat Disord 6:7, 2018), and be associated with significant physical, psychological, and psychosocial impairment (Zucker et al. Pediatrics 136(3):e582–e590, 2015). Given the prevalence, clinical impact, and burden across all the Feeding and Eating Disorders, early and accurate identification of cases has potential to promote improved prevention and treatment and is a global health priority (Erskine et al. Curr Opin Psychiatry 29(6):346–353, 2016; Hay et al. J Eat Disord 11(1):23, 2023).