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  • Writer's pictureCatherine Lott

Refeeding Syndrome

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'Refeeding syndrome' is something most people with an eating disorder are aware of, and , (especially if you are significantly underweight), could be really worried about. There are lots of misunderstandings and misinformation about refeeding and the possible problems that can come with it, and these fears can be seized on by your eating disorder to justify not increasing your intake and not reaching recovery.

Refeeding is the process of re-introducing food after a period of malnourishment or starvation.

Refeeding syndrome is a serious and potentially fatal condition that can occur during the process of refeeding. It is important to remember, though, if you take nothing else away from this post, that it is also rare, preventable and survivable.

A little background

It was identified among the survivors of concentration camps after World War 2 after they tried to recover from months or years of enforced starvation. Accounts can be found, though, as early as the 1st century AD, where the historian Flavius Josephus, described the classic symptoms of the syndrome among survivors of the siege of Jerusalem. He wrote about the death of those who over indulged in food after famine, where as those who ate at a more restrained pace survived (1)

What actually causes refeeding syndrome?

Simply put, refeeding syndrome is caused by sudden shifts in the electrolytes that help our bodies metabolise food.

Risk factors

Although it's commonly associated with reintroducing food in eating disorder recovery, refeeding syndrome can affect anyone. Certain conditions may increase your risks, though, including:




difficulty swallowing (dysphagia) (for example as a result of a stroke)

certain surgeries

long term users of antacids

Long term users of diuretics

BMI is also a useful indicator for your doctor when approaching risk management of refeeding syndrome. A BMI of under 16 is seen as a risk in itself, where one of under 18.5 is seen as a risk when present with another factor, including:

  • Recent unintentional weight loss of 10% or more

  • A history of use of alcohol or drugs, antacids or diuretics

  • Little or no food for five days or more. (2)

The science of refeeding syndrome

Food deprivation changes the way your body metabolises nutrients. For example, insulin is a hormone that breaks down glucose (sugar) from carbohydrates. When carbohydrate consumption is significantly reduced, insulin secretion slows.

In the absence of carbohydrates, the body turns to stored fats and proteins as sources of energy. Over time, this change depletes electrolyte stores. Phosphate, an vital electrolyte that helps your cells convert glucose into energy, is often affected.

When food is re-introduced, the shift from fat metabolism back to carbohydrate metabolism is abrupt. This causes increase of insulin secretion. Cells need electrolytes like phosphate to convert glucose to energy, but phosphate is in short supply, leading to a condition, called hypophosphatemia (low phosphate).

Other metabolic changes can also occur. These include:

  • abnormal sodium and fluid levels

  • changes in fat, glucose, or protein metabolism

  • thiamine deficiency

  • hypomagnesemia (low magnesium)

  • hypokalemia (low potassium) (3)


Symptoms of refeeding syndrome may include:

  • fatigue

  • weakness

  • confusion

  • inability to breathe

  • high blood pressure

  • seizures

  • heart arrhythmias

  • heart failure

  • coma

  • death

These symptoms typically appear within four days of the start of the refeeding process. Though, occasionally some at-risk people don’t develop symptoms, there’s no way to know who will develop symptoms before beginning treatment. As a result, increased awareness and prevention is critical.

The National Institute for Clinical Excellence (NICE) published guidelines for the management of refeeding disorders in 2006 based on a comprehensive review of available research.

Recommended treatment includes oral supplementation various vitamins,including thiamine (B1) , minerals and electrolytes, alongside slow introduction of nourishment (dictated largely by BMI), over 5-10 days. Electrolyte levels should be monitored once daily for a week and at least three times the following week. Urinary electrolytes could also be checked to help assess losses and guide replacement. Intravenous (IV) infusions based on body weight are often used to replace electrolytes. (4)


Recovering from refeeding syndrome depends on the severity of malnourishment before food was re-introduced. Refeeding can take up to 10 days, sometimes requiring monitoring afterwards.

In addition, refeeding, especially with illnesses other than anorexia,(stroke, cancer, diabetes etc.) often occurs alongside other, serious conditions which typically require simultaneous treatment.


Prevention of refeeding syndrome is best achieved through awareness, identification of whether you're more at risk and adapting refeeding programmes accordingly.

To sum up...

Refeeding syndrome is something you need to be aware of if you are in the very early days of your recovery journey from anorexia, especially if you are significantly underweight. It's not something that should hold you back. It is, in fact, a rare survivable phenomenon that can occur during nutrition support in people who are at a risk (5)


(1) The Jewish War, Flavius Josephus, ( c. 75 AD)

(2) Refeeding syndrome: what it is, and how to prevent and treat it Hisham M Mehanna, Jamil Moledina, and Jane Travis

(3)Healthline 'Refeeding Syndrome' C.Vandergriendt

(4)Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutritionClinical guideline [CG32] Published date: February 2006 Last updated: August 2017

(5) Rio A, Whelan K, Goff L, et al Occurrence of refeeding syndrome in adults started on artificial nutrition support: prospective cohort study BMJ Open 2013;3:e002173. doi: 10.1136/bmjopen-2012-002173

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