*2.3. Procedure*

Eligible participants attended a single research session at the Institute of Psychiatry, Psychology & Neuroscience at King's College London, lasting no longer than 1 and a half hours. After having their blood collected, participants had their height and body weight measured, from which BMI (kg/m2) was calculated, and body composition was assessed using a portable and non-invasive Inbody S10 machine, Biospace Co., Ltd. Participants then completed a questionnaire pack, including questions on demographic characteristics, clinical characteristics for AN and recAN participants, and the EPIC-Norfolk FFQ. Participants also completed questionnaires on mental health, data for which have been presented elsewhere [42] and will not be included in the present study.
