The increases in fasting hepcidin levels in both groups were evident after 3 days of an acute energy‐deficient dietary manipulation, which is consistent with previous observations in research investigating LEA in athletes (Ishibashi et al., 2020), negative energy balance during the simulated military tasks (Hennigar et al., 2021), 18, 42 and 66‐h of fasting state (Troutt et al., 2012), and in clinical research with anorexia nervosa patients (Papillard‐Marechal et al., 2012). Here, HAMP is linked to anorexia nervosa.