Anorexia nervosa (AN) is characterized by underweight, and the primary goal of treatment is weight restoration. Treatment approaches (ie, hospitalization for weight recovery vs. for medical stabilization) and settings (ie, medical/pediatric or psychiatric units) for patients with AN vary between and also within countries. Several specialized eating disorder units worldwide have established high-caloric refeeding (HCR) protocols for patients with AN. In observational studies, HCR shortens hospital stays and increases initial weight gain, the latter being associated with a favorable long-term prognosis. However, clinicians may still remain reluctant to accept this approach for fear of medical complications of HCR, including the risk of refeeding syndrome (RS). Research is building toward the development of evidence-based recommendations for safe and effective re-nutrition of underweight patients with AN. This focused review was based on clinical experience and describes 3 different protocols for nutritional management devised by experts from 3 different parts of the world (Australia, Germany, and the United States), in medical refeeding of patients with AN who have established HCR in their clinical units. In addition, and in order to understand energy requirements, empirical data on energy turnover of patients with AN from former metabolic studies are presented. To the best of our knowledge, there is no study reporting on HCR in a cohort of severely malnourished adolescents with AN (ie, with a mean body mass index [BMI] of <15 kg/m). Therefore, to provide information about the treatment of extremely malnourished patients with AN, we included a recently published HCR protocol for adults with a BMI of <13 kg/m..