During starvation ketoacidosis, fatty acids replace glucose as the primary source of fuel for the body. It happens when a person has undergone an extended period of fasting.

Starvation ketoacidosis is rare, but certain people may have a higher risk of developing it than others. Individuals at higher risk include those with eating disorders.

Starvation ketoacidosis can be serious if a person does not seek treatment, and it could even result in death.

This article discusses starvation ketoacidosis in more detail, including its symptoms and how to treat and prevent it.

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Ketoacidosis is a metabolic state associated with high levels of ketones in the blood. Ketones build up when the body breaks down fatty acids to use for energy in place of carbohydrate.

Starvation ketoacidosis occurs when the body has not received enough glucose as its primary energy source for a prolonged period.

There are various reasons why a person may have fasted for a long time, including:

Mild ketosis — meaning that the body uses fat as an energy source — can occur after a 12–14 hour fast.

Ketoacidosis happens when a buildup of ketones causes the blood to become acidic. In starvation ketoacidosis, once the body has run out of fat, it starts to break down muscle, which releases amino acids and lactate into a person’s blood. The liver then breaks these down into sugars to use for fuel.

The transition from ketosis to ketoacidosis can occur after 2–3 days of fasting. After a couple more days, the breakdown of muscle may begin.

Learn more about the difference between ketosis and ketoacidosis here.

According to a 2020 article, there are three types of ketoacidosis:

Diabetic ketoacidosis

Diabetic ketoacidosis occurs when a person’s body starts to run out of insulin, which can be life threatening.

Diabetic ketoacidosis can happen in people with either type 1 or type 2 diabetes, but it is more likely to affect those with type 1 diabetes.

Learn about diabetic ketoacidosis here.

Alcoholic ketoacidosis

According to a 2020 review, alcoholic ketoacidosis mostly affects people who drink excessive amounts of alcohol and find that the resulting symptoms — such as vomiting, anxiety, and abdominal pain — make them unable to eat solid food for 1–3 days.

Alcoholic ketoacidosis happens when a person’s body cannot make use of glucose from their diet.

The alcohol in their blood keeps their blood sugar low and hampers the production of glucose by the liver.

The signs and symptoms of starvation ketoacidosis can include:

A 2020 case report presented information about people with psychiatric issues and starvation ketoacidosis. The authors conclude that making an accurate diagnosis may be more challenging in people with psychiatric disorders, as these individuals may not be able to provide an accurate history of their health or eating habits. As a result, there may be a delay in treatment.

Possible causes of starvation ketoacidosis include:

Most people who have easy access to food have a low risk of developing starvation ketoacidosis.

However, intermittent fasting, particularly in combination with an extreme diet such as the ketogenic diet, can put a person at higher risk of developing ketoacidosis. People interested in following specialized diets, such as the keto diet, should talk with their doctor before starting the diet.

A 2020 article lists the following risk factors for starvation ketoacidosis:

  • having difficulty swallowing, including after surgery or radiation therapy
  • having underlying conditions or diseases that prevent adequate nutrition
  • going for prolonged periods without adequate nutrition

Starvation ketoacidosis does not occur frequently in healthy individuals, as it happens due to a lack of glucose from the diet after long periods of starvation.

Therefore, when starvation ketoacidosis occurs, a person’s doctor may look for other causes of weight loss, which can delay diagnosis and treatment.

If a person experiences unexplained weight loss, they should tell their doctor about:

  • any other symptoms
  • their diet
  • any underlying health conditions

According to a 2020 article, a doctor will first need to stabilize the person before performing necessary tests, including blood tests, to check for electrolyte abnormalities and vitamin deficiencies. If a person receives a diagnosis of starvation ketoacidosis, the doctor will treat them accordingly.

Starvation ketoacidosis occurs when the body becomes deprived of necessary food and energy for a prolonged period. Although eating may seem to be the obvious therapy, it can be dangerous for a person who has lived a long time with malnutrition.

When a doctor treats a person for starvation ketoacidosis, they will need to monitor their electrolytes closely. During the process of introducing food, doctors will need to check and replace a person’s potassium, phosphate, and magnesium.

One case study involved a person living with anorexia who had developed starvation ketoacidosis. Doctors treated this person with a dextrose solution for 15 hours, during which time the ketoacidosis improved.

With proper treatment, including the treatment of underlying health conditions such as anorexia, a person should make a full recovery.

When starvation ketoacidosis occurs, a person’s body will often start to waste away. In other words, they will begin to look thinner or drawn out, and their bones will appear more pronounced.

Another complication is that a person may experience lethargy and a severe loss of strength because the body has begun to break down muscle.

Without treatment, ketoacidosis can be fatal.

People who are living with an underlying health condition or undergoing radiation therapy or surgery should work with their doctor to make sure that they can eat enough food to prevent ketoacidosis.

Help is also available for people living with eating disorders. Although treatment can be challenging, it can lead to recovery, offering the person a full and active life.

Help is available

Eating disorders can severely affect the quality of life of people living with these conditions and those close to them. Early intervention and treatment greatly improve the likelihood of recovery.

Anyone who suspects they or a loved one may have an eating disorder can contact the National Alliance for Eating Disorders, which offers a daytime helpline staffed by licensed therapists and an online search tool for treatment options.

For general mental health support at any time, people can call the Substance Abuse and Mental Health Services Administration 24 hours a day at 1-800-662-4357 (or 1-800-487-4889 for TTY).

Many other resources are also available, including:

Learn more about different types of eating disorder here.

Starvation ketoacidosis is an uncommon form of ketoacidosis. It occurs when a person does not consume enough food on a regular basis or cannot absorb nutrients correctly.

A doctor can check for starvation ketoacidosis with blood tests and will need to monitor the person as they start eating again.

Most healthy people with an adequate supply of food are not at risk. However, people living with eating disorders and those who have undergone certain medical procedures may have a higher risk of developing starvation ketoacidosis.

A full recovery is usually possible with treatment.