Anorexia nervosa — medical risk, refeeding, and stepped care (MEQ)

(i) Diagnosis. Anorexia nervosa, restricting type (no binge/purge described), extreme adult-equivalent severity band if adult BMI rules applied (BMI <15); in adolescents also plot BMI centile/growth failure. Criteria: restriction → significantly low weight; fear of weight gain / interfering behaviours (compulsive running); body image disturbance / lack of seriousness. Differentials: medical causes of weight loss (coeliac, IBD, endocrine, malignancy — screen as indicated), ARFID (no shape overvaluation), depression with appetite loss, substance misuse. Here classic AN psychopathology + ballet context.[6]

(ii) Immediate medical risk. This is medical instability: bradycardia, hypotension, hypothermia, collapse, extreme malnutrition, high exercise load. Admit under joint medical–psychiatric care (MEED/MARSIPAN-type principles). Stop exercise. Continuous monitoring as indicated. Investigations: ECG (bradycardia, QTc), FBC, U&E, phosphate, Mg, Ca, LFT, glucose, TFT, pregnancy test if relevant, consider coeliac serology; serial orthostatic vitals. Suicide risk assessment. Multidisciplinary team within hours.[4][6]

(iii) Refeeding. High risk of refeeding syndrome: insulin-driven intracellular shift of phosphate/K/Mg after carbohydrate reintroduction → hypophosphataemia and cardiorespiratory risk. Plan: protocolised refeeding (oral if safe; NG if needed) with thiamine/multivitamins per protocol; frequent phosphate/K/Mg monitoring and proactive replacement; fluid balance; do not use unsupervised high-carb boluses. Higher-calorie protocols can restore medical stability faster in carefully monitored youth inpatients (StRONG) but require infrastructure — follow local protocol under senior dietitian/physician.[2][3]

(iv) Psychological treatment. After medical stabilisation pathway begins, first-line for adolescents is family-based treatment (FBT): empower parents for renourishment (Phase 1), return control (Phase 2), developmental issues (Phase 3). Lock RCT supports FBT over adolescent-focused individual therapy for remission outcomes. Address family accommodation at meals. Individual CBT adaptations if FBT unsuitable; not olanzapine as primary adolescent plan.[1][6]

(v) Capacity and compulsion. Capacity is decision-specific (admission, NG feeding). Assess understanding, retention, weighing, communication. AN beliefs and starvation can impair appreciation of life-threatening risk despite intellectual “knowledge.” If incapacity + high risk, use jurisdiction-specific mental health/guardianship law for least-restrictive compulsory care, second opinions, and ethical review — do not invent foreign section numbers. Document least restrictive options tried.[5]