Objective To examine the impact of our new rapid refeeding protocol on patients with anorexia nervosa (AN) in our Eating Disorders Program. We hypothesize that the new protocol would lead to a more rapid weight gain and a shorter length of stay, with no effect on medical complications or program completion. Method This cohort design included consecutive inpatients and day hospital patients admitted to the program with a BMI <18 kg/m2 and a diagnosis of AN between 2007 and 2020; N = 326 patients. Main outcomes measured were rate of weight gain and length of stay. Safety indicators included electrolyte disturbances and supplementation required, complications including refeeding syndrome and completion of the program. A p value <.05 was considered statistically significant. Results Total length of stay was 21 days shorter for patients on the rapid refeeding protocol compared to the traditional refeeding protocol. Patients on the new protocol gained 0.21 more kg/week compared to patients on the old protocol. There was no difference in completion rates between programs. Electrolyte imbalances were mild to moderate and easily treated with oral electrolyte supplementation. There were no deaths or cases of refeeding syndrome with either protocol. Discussion This is the first Canadian study to assess the effectiveness and safety of rapid refeeding in an adult population. Rapid refeeding protocols can be safely administered and are cost effective. Shorter hospital admissions are desirable to minimize possible regression and dependency on inpatient services and positively impacts patients' quality of life. Public Significance This study advances the idea that rapid refeeding in patients with anorexia nervosa can be administered safely and effectively with close medical monitoring. In addition, rapid refeeding leads to shorter hospital stays, with a cost‐savings to the health system. Shorter admissions are desirable to minimize possible regression and dependency on inpatient services and also positively impacts patients' quality of life.