The key diagnostic criteria for anorexia nervosa according to the DSM-5 include:
- Restriction of energy intake leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health.
- Intense fear of gaining weight or becoming fat, or persistent behaviour that interferes with weight gain, even though at a significantly low weight.
- Disturbance in the way one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.
These criteria reflect a core psychopathology characterised by restrictive eating behaviours, a distorted body image, and an intense fear of weight gain, which together result in severe undernutrition and associated physical and psychological complications NICE NG69; Call et al. 2013. The DSM-5 removed the amenorrhea criterion present in DSM-IV, recognising that anorexia nervosa can occur in males and females regardless of menstrual status Call et al. 2013. The UK NICE guideline on eating disorders aligns with these criteria by emphasising the importance of assessing unusually low body weight or BMI, restrictive eating practices, and disproportionate concern about weight or shape as key indicators for anorexia nervosa NICE NG69.
Additionally, the NICE guideline highlights the need to consider physical signs of malnutrition and compensatory behaviours such as vomiting or excessive exercise, which often accompany anorexia nervosa and contribute to diagnosis and risk assessment NICE NG69. The guideline also stresses that diagnosis should not rely solely on BMI or duration of illness but on a comprehensive clinical assessment including psychological and physical health NICE NG69.
In summary, the DSM-5 diagnostic criteria focus on behavioural restriction leading to low weight, fear of weight gain, and body image disturbance, which are supported and operationalised in clinical practice by the UK NICE guideline recommendations for assessment and diagnosis of anorexia nervosa NICE NG69; Call et al. 2013.