Anorexia nervosa (AN) is a serious mental illness. It is frequently accompanied by a history of childhood maltreatment (CM) that may constitute a specific ecophenotype in patients with eating disorders necessitating special assessment and management. This retrospective study tested whether in patients with AN, CM-related chronic stress may manifest through low-grade inflammation reflected by an increase in white blood cell ratios (neutrophil-to-lymphocyte ratio, NLR, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio).