What Is Refeeding Syndrome?

Refeeding is the process of safely reintroducing food to a person after a long period of starvation or malnourishment (via Internal and Emergency Medicine). It's one of the first steps in the long-term nutritional rehabilitation of patients with anorexia nervosa. Refeeding helps build up the body's reserves, per WebMD. While the procedure saves lives, it can also have life-threatening side effects in some cases.

Per Internal and Emergency Medicine, refeeding syndrome is a serious condition that can occur when people are rapidly fed nutrients after severe malnutrition. It's caused by a sudden shift in electrolytes and fluids in the blood, which aid many bodily functions.

When the body has been starved for a long time, it undergoes numerous changes to compensate for the lack of nutrients (via BMJ). If a person is refed too quickly, this sudden influx of nutrients can trigger an electrolyte imbalance. This can cause problems with the heart, lungs, and other organs, and it could even result in death, warns Internal and Emergency Medicine. Read on to find out more about this potentially fatal complication.

Refeeding syndrome typically arises within 5 days of refeeding, and it can manifest in a variety of ways (via Internal and Emergency Medicine). A common symptom is abdominal discomfort. The patient may experience problems like diarrhea as well as nausea and vomiting. These are usually caused by a shift of magnesium when carbohydrates are abruptly introduced into the body.

Other common symptoms include confusion and fatigue, which can stem from phosphate imbalance, notes Internal and Emergency Medicine. Many patients have muscle pain and weakness. They may experience hypoxia, which is a lack of oxygen in the body's cells and tissues. People with hypoxia often feel restless and disoriented, and they may struggle to catch their breath as their heart rate rapidly speeds up and their skin begins to turn blue. If this isn't treated fast enough, organs can start to deteriorate, per Cleveland Clinic.

Refeeding syndrome can have devastating effects, according to Internal and Emergency Medicine. It can result in cardiac arrhythmia, respiratory failure, and heart failure. Cleveland Clinic adds that other possible symptoms include seizures, muscle weakness, muscle spasms, delirium, amnesia, and more. Refeeding syndrome can even send a patient into a coma.

It's estimated that the incidence of refeeding syndrome in people who are severely malnourished can be as high as 48% (via Internal and Emergency Medicine). This includes people who have had little or no nutrition for numerous consecutive days (via Current Gastroenterology Reports). It also affects individuals who've experienced metabolic stress due to a critical illness or a major surgery.

Certain groups of people who have been hospitalized are particularly vulnerable, according to Current Gastroenterology Reports. Refeeding syndrome is reported in up to 25% of cancer inpatients. It can also occur in patients who have an eating disorder, chronic alcohol or drug use, short bowel syndrome, chronic diabetes, or other health conditions. Other subsets of patients that are at an increased risk include the elderly and those who are postoperative.

Individuals who are at an elevated risk include those who are severely underweight or have lost 15% or more of their normal body weight in three to six months, and people with lower than normal levels of electrolytes (via Current Gastroenterology Reports). It's said to occur in 33% of patients with anorexia, per Internal and Emergency Medicine.

Prevention can help avoid the potentially fatal consequences of refeeding syndrome (per The BMJ). So it's important for clinicians to make sure that patients receive a thorough nutritional assessment beforehand. Clinicians should identify any risk factors such as nutritional and electrolyte imbalances, adapt refeeding programs according to the individual, and monitor electrolyte and glucose levels before and during feeding.

In order to prevent the body's systems from becoming overwhelmed, a person should be refed slowly and steadily to give the body time to adjust. The rate of reintroducing food to patients will depend on the severity of malnourishment. But experts recommend that for people at risk of refeeding syndrome, refeeding should start at a maximum of 50% of the goal caloric intake for the first few days, and slowly increase calories in the following days to meet the full caloric target (via Clinical Nutrition). Patients with a vitamin deficiency or imbalance may also require vitamin supplementation, notes The BMJ.

It's crucial that the imbalances created by refeeding syndrome are treated quickly. Cleveland Clinic notes that refeeding syndrome may be treated by slowing down the refeeding, reducing carbohydrates in the formula, and using an IV to restore missing nutrients.