Refeeding Syndrome

What is refeeding syndrome?

Refeeding syndrome can occur when a person is recovering from a period of starvation. If a starving person is fed too aggressively, it can cause refeeding syndrome, which is a dangerous and sometimes fatal condition. It is associated with low levels of phosphate, potassium, and magnesium in the bloodstream.

Who gets refeeding syndrome?
Refeeding syndrome is most commonly seen in patients who have anorexia nervosa, chronic alcoholism, cancer, chronic malnutrition, uncontrolled diabetes, or are post-op and/or have not eaten well for several days. Individuals who are obese and have severely restricted calories and/or sudden weight loss are also at risk. Refeeding syndrome can occur in patients who eat orally or in those who depend on tube feeding for their nutrition.

Why does refeeding syndrome occur?
Refeeding syndrome occurs because the body adapts to starvation. Under normal conditions, the body uses carbohydrate from the diet for energy. If no food is available for 24 hours, the body uses energy that is stored in the liver and muscles. After about 3 days, the body adapts again and uses other stored sources of energy. After a few days of starvation, the body becomes used to starvation.

When a person finally begins eating, the body suddenly shifts back to food as its source of energy. During this shift, changes occur in the body processes, which result in fluid and electrolyte imbalances and vitamin deficiencies.

What happens when a person has refeeding syndrome?
Individuals with refeeding syndrome are deficient in potassium, magnesium, and phosphorus, and often are deficient in fluid and a vitamin called thiamine. These nutrients are involved in many important body processes.

As a result of nutrient imbalances, patients who are suddenly refed can have serious complications, including:

  • Heart problems
  • Breathing problems
  • Impaired mental status
  • Seizures
  • Paralysis
  • Insulin resistance
  • Bone problems

Deaths also have occurred that are associated with refeeding syndrome. 

Can you prevent refeeding syndrome?
Yes, usually. The key is to identify if a patient is at risk for refeeding syndrome because of poor intake over a period of time. Once a person is identified as at risk, it is necessary to provide food and fluids slowly during the refeeding process. It is dangerous to provide too many calories and too much fluid to a person whose body has adapted to starvation.

What is the right way to nourish a patient with refeeding syndrome?
It is most important for anyone who was starved for several days to resist the urge to eat and drink large amounts of food or liquid. Several small meals and fluids in small quantities are key to renourishing a starving body. For acutely ill or postsurgical patients who are on tube feeding, it is necessary to provide the feeding in small amounts and then gradually increase the amount.

To prevent refeeding syndrome, a person should not receive full feeding and hydration for several days after a period of starvation. It is important to carefully monitor blood nutrients, as well as tolerance to food and fluids. A registered dietitian can help determine how much food and fluids to provide to prevent refeeding syndrome.

How do I know if someone is at risk for refeeding syndrome?
If a patient has gone without much food and/or fluid for 3 or more days, the person is possibly at risk for refeeding syndrome. In general, the more severe the malnutrition, the higher the risk for refeeding syndrome.


References and recommended readings
Kraft MD, Btaiche IF, Sacks GS. Review of the refeeding syndrome. Nutr Clin Pract. 2005;20(6):625-633.

McCray S, Walker S, Parrish CR. Much ado about refeeding: nutrition issues in gastroenterology, series #23. Practical Gastroenterology, January 2005;26-44. Accessed May 7, 2013.

Nutrition Care Manual®. Academy of Nutrition and Dietetics Web site [by subscription]. Accessed May 7, 2013.


Review Date 5/13