The Refeeding Syndrome: An Overview

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Contributor: Margherita Mascolo, MD, Medical Director, ACUTE Center for Eating Disorders at Denver Health

Refeeding syndrome occurs as a starved person begins to take in nutrition. During early nutritional rehabilitation, also known as refeeding, serious and potentially fatal complications may occur from a shift in fluids and electrolytes within the body.

Symptoms of the refeeding syndrome include weakness, inability to breathe, seizures, mental confusion, cardiac arrest, heart failure, coma and even death. Any patient who is at risk for refeeding syndrome should be under the care of an experienced physician, ideally in a medical hospital where the care team can react quickly to the patient’s medical needs.

Risk Factors

According to the National Institute for Clinical Excellence (NICE), any patient who meets the following criteria is at risk for refeeding syndrome.

ONE or more of the following:

  • BMI of less than 16 kg/m2
  • Weight loss of more than 15% body weight in the previous 3-6 months
  • Little or no nutritional intake for more than 10 days
  • Low levels of potassium, phosphorus, or magnesium before refeeding

Or TWO or more of the following:

  • BMI less than 18.5 kg/m2
  • Weight loss of more than 10% body weight in the previous 3-6 months
  • Little or no nutritional intake for more than 5 days
  • History of alcohol or drug abuse (including insulin, laxatives, and diuretics)

Not all patients who are at risk will develop full refeeding syndrome. However, an outcomes study published by the ACUTE Center for Eating Disorders at Denver Health found that there is no single marker to identify which of the at-risk patients would develop complications of refeeding syndrome. Therefore, it is critical that every at-risk patient is medically monitored by experienced professionals to prevent fatal complications .

The Refeeding Process

During the early refeeding process, the body goes from a catabolic state (breaking down tissues for nutrients during malnutrition) to an anabolic state (rebuilding and repairing tissues). It switches from breaking down fat cells for nutrients to using carbohydrates as building blocks to repair and regenerate cells.

Woman on rockDuring this time the body secretes a number of hormones that have been dormant during the starvation period. These hormones aid the body in the production of new cells. This repair effort causes electrolytes such as potassium and phosphorus to shift out of the blood and into cells thus lowering their blood concentration.

The key electrolyte in refeeding syndrome is phosphorus, a crucial component of the body’s energy molecules. During early refeeding, phosphorus levels can become dangerously low leading to muscle damage, weakness, cardiac arrhythmias, and death. Another critical electrolyte in the refeeding process is potassium. A decreased potassium level in the blood may lead to seizures, cardiac arrhythmias, and death. Fatal complications from these electrolyte abnormalities can be avoided with daily lab checks and aggressive replacement of electrolytes.

Another common physiologic change that occurs during the refeeding process is refeeding edema or swelling (not to be confused with the edema caused by Pseudo-Bartters syndrome which can occur upon the cessation of purging). During the refeeding process, one of the many hormones at play is insulin. When insulin secretion increases it makes the kidneys hold on to salt and water.

This water retention is seen as swelling, typically in the lower extremities. The accumulation of fluid and the visible changes it causes in the lower extremities is very distressing, especially for patients suffering from severe eating disorders and associated body dysmorphia. There is no treatment for refeeding edema and in most cases it will resolve with continued nutritional rehabilitation. It is important to set expectations and provide reassurance that refeeding edema will resolve with nutrition and time.

Management of Refeeding Syndrome

Woman in recoveryRefeeding syndrome should be managed in a specialized facility where telemetry (heart monitoring) is available, labs can be drawn multiple times daily, and where staff know the physiologic abnormalities that inevitably occur. Expert care is key to ensuring patients are kept safe during the refeeding process.

At the ACUTE Center for Eating Disorders at Denver Health we treat the highest volume of the most medically ill patients with eating disorders. We specialize in knowing the risk factors for refeeding syndrome, treating and avoiding its potentially fatal medical complications, and safely guiding patients to definitive medical stabilization.

Headshot Margherita Mascolo Refeeding Syndrome specialistAbout the Author: Margherita Mascolo, MD is a Board-Certified Internal Medicine Specialist, Medical Director at ACUTE Center for Eating Disorders and Assistant Professor of Medicine at the University of Colorado.

Dr. Mascolo is the Interim Medical Director of ACUTE Center for Eating Disorder and a hospitalist at Denver Health. She completed her undergraduate work at the University of St. Thomas in Houston, Texas and earned her medical degree at the University of Texas Health Sciences Center. She completed her residency in Internal Medicine at the University of Colorado in Denver. She is board certified in Internal Medicine and is an Assistant Professor in the Department of Medicine at the University of Colorado. Dr. Mascolo is also proud to serve as Medical Liaison Chairperson for the IAEDP Denver Chapter.


[1]: National Collaborating Centre for Acute Care, February 2006. Nutrition support in adults Oral nutrition support, enteral tube feeding and parenteral nutrition. National Collaborating Centre for Acute Care, London. Available from
[2]: Gaudiani, J. L., Sabel, A. L., Mascolo, M., & Mehler, P. S. (2010). Severe anorexia nervosa: Outcomes from a medical stabilization unit. International Journal of Eating Disorders, 45(1), 85-92. doi:10.1002/eat.20889

The opinions and views of our guest contributors are shared to provide a broad perspective of eating disorders. These are not necessarily the views of Eating Disorder Hope, but an effort to offer discussion of various issues by different concerned individuals.

We at Eating Disorder Hope understand that eating disorders result from a combination of environmental and genetic factors. If you or a loved one are suffering from an eating disorder, please know that there is hope for you, and seek immediate professional help.

Last Updated & Reviewed By: Jacquelyn Ekern, MS, LPC on December 28, 2016
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