BED vs BN ICD-11 Distinction — MRCPsych Paper B MCQ

Correct answer: D — Whether recurrent inappropriate compensatory behaviours are used to prevent weight gain

The correct answer is D. Both binge eating disorder and bulimia nervosa involve recurrent binge-eating episodes characterised by loss of control. The key distinction is that bulimia nervosa includes recurrent inappropriate compensatory behaviours intended to prevent weight gain, such as self-induced vomiting, laxative misuse, fasting or excessive exercise. In binge eating disorder, the binge-eating episodes occur without these recurrent compensatory behaviours. Age at onset, sex and body mass index do not define the distinction: either disorder can occur across demographic groups and at a range of body weights. Frequency alone is also insufficient because recurrent binge eating is required in both disorders; it is the relationship between binge eating and compensatory behaviour that differentiates them.

Reference: NHS England, Adult Psychiatric Morbidity Survey: Survey of Mental Health and Wellbeing, England, 2023/4, Chapter 13, section 13.2 'Definitions and assessments', 2025 (updated 2026). https://digital.nhs.uk/data-and-information/publications/statistical/adult-psychiatric-morbidity-survey/survey-of-mental-health-and-wellbeing-england-2023-24/eating-disorders