What is refeeding?

What is refeeding?

Refeeding syndrome can develop when someone who is malnourished begins to eat again. The syndrome occurs because of the reintroduction of glucose, or sugar. As the body digests and metabolizes food again, this can cause sudden shifts in the balance of electrolytes and fluids. These shifts can cause severe complications, and the syndrome can be fatal.

It may take as little as five consecutive days of malnutrition for a person to be at risk of refeeding syndrome. The disease can be treated and can be stopped if doctors notice warning signs early.

Symptoms of the condition typically become evident within a few days of malnourishment diagnosis.

What are the causes of refeeding syndrome?

Refeeding syndrome can occur when food is reintroduced to a person who is malnourished.

When a person doesn’t eat enough, he or she will easily go into starvation mode and become malnourished.

The ability to store food is seriously pimpaired after a prolonged period of famine.

A malnourished body produces less insulin, and this reduces carbohydrate development.

When the body has insufficient carbohydrates, it uses nutrition from the fat stores and stored proteins.

When the body tends to depend on fat and protein stores over time this will alter the electrolyte balance. Vitamin and electrolyte levels are rising as the body continues to adjust to the mode of starvation. The levels of potassium, phosphorus, magnesium, calcium and thiamine are usually impacted.

Once food is reintroduced the body no longer has to rely on fat and protein stores to produce energy.

Refeeding therefore requires an sudden metabolism change. It occurs with an rise in glucose, and the body responds with more insulin secretion. It will result in a lack of electrolytes, including phosphorous.

Refeeding syndrome may cause hypophosphatemia, which is a phosphorus deficiency disease. This may also cause other essential electrolytes to have low levels.

The adverse effects of refeeding syndrome are common, and may include:

  • heart
  • lungs
  • kidneys
  • blood
  • muscles
  • digestion
  • nervous system

If doctors are unable to treat the syndrome, it can be fatal.

Who is at risk?

Refeeding syndrome affects people who do not receive enough nutrition.

This may be because of:

  • starvation
  • malnourishment
  • extreme diets
  • fasting
  • famine

The following medical conditions can also increase the risk of developing refeeding syndrome:

Undergoing particular surgeries, especially weight loss surgeries, can also increase a person’s risk.


Electrolytes play a very important role in the body. The most common problem when the balance is distorted is hypophosphatemia which is a lack of phosphorus.

Symptoms of hypophosphatemia include:

  • confusion or hesitation
  • seizures
  • muscle breakdown
  • neuromuscular problems
  • acute heart failure

Refeeding syndrome may also cause magnesium deficiency. Hypomagnesemia is the term for hazardously low magnesium levels.

Signs and symptoms of hypomagnesemia include:

  • low calcium levels, or hypocalcemia
  • low potassium levels, or hypokalemia
  • weakness
  • fatigue
  • nausea and vomiting
  • abnormal heart rhythms

Refeeding syndrome can also cause a dangerously low fall in potassium levels. It might lead to:

  • fatigue
  • weakness
  • excessive urination
  • breathing problems, such as respiratory depression
  • heart problems, such as cardiac arrest
  • ileus, which involves a blockage in the intestines
  • paralysis

Other symptoms include:

  • hyperglycemia, or high blood sugar
  • mental problems, such as confusion
  • abnormal serum sodium levels
  • fluid retention
  • muscle weakness

In some cases a deficiency in potassium can lead to a coma or death.

Doctors can identify people at risk for refeeding syndrome, but it can’t be known if a person will develop it. It’s important to try to keep the condition from developing.

Risk factors

Bottom of alcohol
A history of alcohol use disorder can put a person at risk for refeeding syndrome.

Those who have previously died of starvation have the greatest chance of developing refeeding syndrome.

If a individual has an extremely low index of body mass, the risk is high.

People who have lost weight quickly recently, or who had little to no food before beginning the refeeding cycle are also at substantial risk.

Other people at risk include:

  • children or adolescents with severely restricted calorie intakes, when this occurs with vomiting or laxative misuse
  • children or adolescents with a history of refeeding syndrome
  • frail individuals with multiple medical problems

Regardless of age, a person is at high risk if they have:

  • a BMI of less than 16
  • lost more than 15 percent of their body weight unintentionally in the past 3–6 months
  • consumed minimal food over the past 10 consecutive days or more
  • low levels of serum phosphate, potassium, or magnesium

Two or more of the following issues also increases the risk of developing refeeding syndrome:

  • a BMI of less than 18.5
  • unintentionally losing 10 percent of body weight in the past 3–6 months
  • consuming little or no food in the past 5 consecutive days or more
  • a history of alcoholism or drug abuse
  • receiving some treatments, such as insulin, diuretics, chemotherapy drugs, radiation therapy, and antacids

Anyone suspecting having refeeding syndrome should receive urgent medical attention.

What are the treatment options?

People with refeeding syndrome need to get back to normal electrolyte levels. This can be done by doctors removing electrolytes, normally intravenously.

Vitamin replacement, such as thiamine, can also help to relieve other symptoms. A person will need a continuous replacement of vitamins and electrolytes before the levels stabilize.

The refeeding process can also be delayed by doctors to help a person relax and heal.

In a hospital the person will require continuous observation. Doctors can use procedures to track electrolyte levels and body functions, including urine and blood samples.


Times of recovery differ depending on the severity of the disease and malnutrition.

Treatment can last for up to 10 days and follow up can last.

When a person has complications or underlying medical conditions, treatment may lead to longer periods of recovery.

Can it be prevented?

The most effective way to tackle refeeding syndrome is by avoidance.

Health care workers who are conscious of warning signs and risk factors are better able to handle people suffering from malnourishment.

Researchers found in 2013 that 4 percent had refeeding syndrome in a wide group of people being fed intravenously in the UK. The authors noted that about half of the at-risk patients had the risk identified by physicians.

Healthcare professionals may prevent the syndrome of refeeding through:

  • quickly identifying those at risk
  • adapting refeeding programs
  • monitoring patients continuously once treatment has begun

Malnourishment can result when food intake is severely limited. This may occur in people with:

  • depression
  • dysphagia
  • alcoholism and drug use
  • anorexia nervosa
  • uncontrolled diabetes

Surgery and diseases such as cancer can contribute to increased metabolic demands, which can contribute to malnutrition.

In addition, malnutrition may occur when the body no longer absorbs nutrients as it should. It may be caused by disorders like celiac disease and inflammatory bowel disease.

High risk patients with malnutrition and refeeding syndrome need to be detected and treated. Guidelines note that prior to refeeding, doctors would assess an individual’s alcohol consumption, diet, weight changes, and psychological health.


Refeeding syndrome may occur after a time of starvation or malnutrition, when food is reintroduced too quickly. This can lead to electrolyte imbalances and severe, possibly fatal complications.

The best way to combat the refeeding syndrome is by finding and treating people at risk. People with the syndrome will recover early on when they undergo care. Might help with education and increased knowledge of the disease.