Ketosis and ketoacidosis both involve the production of ketones in the body. However, while ketosis is generally safe for adults without health conditions, ketoacidosis can be life threatening.
Nutritional ketosis occurs when the body starts using fat for energy instead of glucose. A ketogenic diet, or “keto” diet, aims to induce ketosis. It involves eating high amounts of protein and fat and low amounts of carbohydrates.
Ketoacidosis occurs when the body produces dangerously high levels of ketones. It is most often a complication of type 1 diabetes, but rarely, it can also occur in people with severe malnutrition.
This article examines the differences between ketosis and ketoacidosis, including their symptoms. It also explains when to see a doctor and how to treat and prevent ketoacidosis.
Ketosis occurs when the body uses fat instead of glucose as fuel. The liver breaks down this fat into chemicals known as ketones and releases them into the bloodstream. The body is then able to use the ketones as an energy source.
The ketogenic diet aims to induce nutritional ketosis. People do this by eating foods that are high in fat but very low in carbohydrates.
Doctors originally developed the ketogenic diet to treat children with epilepsy. The “classic” ketogenic diet involves eating 3 to 4 grams (g) of fat for every 1 g of carbohydrate and protein, with 90% of all calories coming from fat.
According to the Epilepsy Foundation, studies show that more than 50% of children who try the diet have half the number of seizures or fewer, while 10% to 15% become seizure-free.
In contrast, ketoacidosis occurs when the body thinks that it is starving and starts breaking down fats stored in the liver. It is usually caused by type 1 diabetes, although it can also occur in type 2 diabetes.
If a person does not have enough insulin or the body cannot use it effectively, glucose cannot move from the blood into cells, where the body uses it for energy. As a result, dangerous levels of both glucose and ketones can accumulate in the blood, making it acidic. Doctors refer to this condition as diabetic ketoacidosis.
Rarely, ketoacidosis can also occur due to severe malnutrition, which is known as starvation ketoacidosis.
For most people, ketosis is a short-lived metabolic state that happens when the body temporarily switches from burning glucose to burning fat.
During this time, the level of ketones in the blood rises but may return to typical levels when a person eats carbohydrates again.
People on ketogenic diets aim to spend more extended periods in ketosis, which may lead to symptoms, particularly when they first begin the diet. This is known as “keto flu“. People
- headaches
- tiredness
- nausea or vomiting
- constipation
- insomnia
These symptoms may last a few days or weeks. People can also experience rapid weight loss.
Although the state of ketosis is generally safe in the short term, as long as a person is getting enough energy and nutrients from their food, it may increase the risk of kidney stones, fat accumulation in the liver (hepatic steatosis), and digestive problems due to a lack of fiber.
Additionally, because the keto diet requires people to limit all sources of carbohydrates, including fruits, starchy vegetables, and other nutritious foods, it may lead to people developing nutrient deficiencies.
Malnutrition can have a wide range of effects, including:
- fatigue
- weakness
- dry skin
- hair loss
- loss of muscle or bone density
- difficulty concentrating or memory problems
- changes in mood
- feeling cold
- anemia
- getting ill more frequently
Scientists do not know what the long-term effects of the keto diet are.
Diabetic ketoacidosis is a potential complication of type 1 diabetes, and it can occur if a person does not administer enough insulin at the correct times.
If a person with diabetes does not eat enough food, it could trigger ketoacidosis. Other triggers
- injury
- surgery
- infections
- other acute illnesses
The symptoms of diabetic ketoacidosis include:
- thirst and frequent urination
- exhaustion
- dry or flushed skin
- high blood glucose levels
- rising levels of ketones in the urine
As ketoacidosis progresses, symptoms can include:
- a fruity odor in the breath
- nausea and vomiting
- stomach pain
- trouble breathing
- confusion and difficulty paying attention
- loss of consciousness
Ketoacidosis is a medical emergency and requires immediate treatment.
Treatment of ketoacidosis
Doctors usually treat people with diabetic ketoacidosis in the hospital. Treatment typically involves insulin therapy together with fluid and electrolyte replacement.
All people with diabetic ketoacidosis will need to stay in the hospital for monitoring. If the cause is unknown, doctors may recommend additional testing.
If ketoacidosis is due to malnutrition, doctors will gradually reintroduce nutrients into a person’s diet. According to the National Health Service (NHS) in the United Kingdom, doctors may also recommend taking certain vitamins or minerals.
Doing this can help prevent a complication known as refeeding syndrome, which is a potentially serious electrolyte imbalance that can occur when a person begins eating again.
People with diabetes can reduce their risk of ketoacidosis by eating a nutritious diet and avoiding prolonged periods without food.
Those with diabetes also need to:
- monitor blood glucose levels regularly
- avoid skipping meals
- avoid dehydration
- take insulin according to the doctor’s treatment plan
- notify a doctor if blood sugar levels are not manageable
- test the urine for ketones if blood glucose levels are above 240 milligrams per deciliter (mg/dl)
- avoid exercise if ketones are present in the urine and blood glucose levels are high
- seek treatment for infections or injuries immediately
Nutritional ketosis is not a medical condition and does not require treatment. A person can resume eating a typical amount of carbohydrates at any point, and their body will stop being in ketosis.
If a person following the keto diet experiences persistent or unusual symptoms, they should speak with a doctor or dietitian.
Ketoacidosis is a life threatening condition. Anyone with the symptoms of ketoacidosis should seek immediate medical attention.
People who have an eating disorder or other conditions that make eating enough food challenging should speak with a doctor for support as soon as they can.
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:
- The National Association of Anorexia Nervosa and Associated Disorders
- F.E.A.S.T., which provides support and educational resources to friends and family who want to help someone living with an eating disorder
There is not enough research to determine how long it is safe to be in ketosis. While research has established the potential benefits and risks for up to 2 years, there is a lack of research on the long-term effects.
Ketosis can turn into ketoacidosis if a person does not eat for prolonged periods or if they remove carbohydrates from their diet altogether.
Several case studies have observed this, including one from 2019 and another from 2020.
These highlight the importance of following the keto diet safely. Anyone with concerns should speak with a doctor or dietitian.
Ketoacidosis is a medical emergency. People should not attempt to treat it themselves. Instead, call 911 or an ambulance and go to the nearest emergency department.
Do not drive to the hospital, as this could be dangerous.
Although ketosis and ketoacidosis both cause ketone levels in the body to rise, they are not the same. Nutritional ketosis is the aim of the ketogenic diet, and scientists believe it can be safe in the short term, whereas ketoacidosis is very dangerous.
People most at risk for ketoacidosis include those with type 1 diabetes, but it can also occur in people who have gone without food for prolonged periods.
People with diabetes should avoid ketogenic diets and follow their doctor’s treatment recommendations to prevent ketoacidosis.
