Background: Anorexia Nervosa (AN) is a life-threatening mental illness that can cause significant medical complications, including the potentially fatal refeeding syndrome. Registered dietitians (RDs) are a critical part of an eating disorder multidisciplinary team that focuses treatment on safe weight restoration and nutrition rehabilitation. Method: This study is a description of how the nutrition rehabilitation protocol of 395 adult patients diagnosed with AN and admitted to residential eating disorder treatment is implemented, how the protocol is sustained throughout a patient’s treatment stay to achieve desired weight gain, and how the patients’ biochemical and clinical progress proceeded between admission and discharge, including laboratory results and body mass index (BMI). Results: One hundred twenty-six patients required phosphorus supplementation for refeeding hypophosphatemia (RH); admission BMI was not significantly different between those with and without RH. The 15% of patients who required enteral nutrition at any point during their admission gained significantly less weight than patients who only received an oral meal plan. 34.4% of patients admitted with starvation induced hepatitis, 28.6% experienced refeeding hepatitis at some point, 21.0% of patients had elevated liver function tests 2 weeks into refeeding and 28.6% at discharge. Conclusions: This study demonstrated overall effectiveness in achieving weight restoration goals with aggressive kcal increases without a single incidence of refeeding syndrome and infrequent RH. No significant biochemical changes were observed during refeeding. With close medical supervision and concurrent RD oversight, a refeeding approach with consistent calorie increases that is more aggressive than previously recommended appears to be safe.