Everything You Need to Know about Keto Flu

Everything You Need to Know about Keto Flu

The ketogenic diet has been extremely popular for losing weight and improving health. It includes eating high fat, moderate protein, and low carbohydrates.

White the keto diet is considered safe for most of the individuals, some unwanted side effects may accompany.

The keto flu, also known as the carb flu, is a term used by the people to describe the set of symptoms they experience when they begin this diet.

This article explores what a keto flu is, why it happens and how to get rid of it.

What is Keto Flu?

The keto flu refers to a collection of symptoms that certain people experience as they start observing the keto diet.

These symptoms may feel similar to the common flu and occur as your body adapts to a new diet with fewer carbohydrates than before.

As you reduce your carbohydrate intake, your body starts relying on the ketones to derive energy instead of glucose. These ketones are produced during fat breakdown and become the primary fuel source while a person follows a keto diet.

In normal conditions, fat is considered as a secondary fuel source to utilize when glucose is unavailable. As the body switch to burning fat for obtaining energy, a process called ketosis takes place. This mainly occurs due to special circumstances which include fasting and starvation.

Because a ketogenic diet reduces your carbohydrate intake to less than 50 grams per day, this drastic change may shock the body. This consequently leads to withdrawal-like symptoms, just like the symptoms you experience while weaning off an addictive agent such as caffeine.

Everything You Need to Know about Keto Flu

What are the Symptoms?

The symptoms of keto flu can be:

  • Nausea
  • Headache
  • Constipation
  • Vomiting
  • Diarrhea
  • Weakness
  • Irritability
  • Dizziness
  • Muscle cramps
  • Unable to concentrate
  • Pain in stomach
  • Difficulty in sleeping
  • Muscle soreness
  • Sugar cravings

How to Get Rid of Keto Flu

The keto flu can actually make you feel miserable. However, there are a number of ways to reduce the symptoms and aid your body in getting through the transition phase a lot more easily.

Stay Hydrated

Drinking water is extremely essential to maintain optimal health and reduce symptoms. This is especially true if you are following a keto diet.

A keto diet may cause your body to rapidly lose water stores. This can increase the risk of dehydration. This is because glycogen, the stored form of the carbs, can bind to the water. As you reduce the dietary carbohydrates, the levels of glycogen reduce, and the bound water gets excreted from the body.

Maintaining hydration can, therefore, alleviate the symptoms like muscle cramping and fatigue.

Replacing fluids is particularly important when you experience the symptoms of keto flu such as diarrhea as this may lead to an additional fluid loss.

Avoid Strenuous Exercise

Exercise is extremely important to maintain health and keep the body weight in check. However, you should be careful not to indulge in any strenuous exercise especially when you are experiencing keto flu.

Muscle cramps, fatigue, and stomach discomfort and among the commonest symptoms experienced during the first week of a ketogenic diet. So, it will be a great idea to give your body the much-needed rest.

Stay away from activities like running, intense biking, weight lifting, and strenuous workouts until your body adapts to its new fuel sources. On the other hand, try walking, leisurely biking, or yoga as they may improve the symptoms.

Replace Electrolytes

Replacing your dietary electrolytes is another way to help get rid of the keto flu and its symptoms.

As you are following a ketogenic diet, the levels of insulin tend to decrease. Insulin is a hormone that helps regulate glucose in the bloodstream. As the number of insulin decreases, the kidney starts excreting sodium from your body.

Other than this, the keto diet also restricts many foods which are high in potassium such as beans, fruits, and starchy vegetables.

Therefore, getting a sufficient amount of these important nutrients is a great way to speed up your adaptation period.

Don’t forget to salt your foods to taste and eat more keto-friendly foods rich in potassium such as green leafy vegetables and avocados.

Get Sufficient Sleep

Irritability and fatigue are some common complaints of people adapting to a ketogenic diet. Lack of sleep triggers the release of a stress hormone called cortisol. This hormone can negatively impact your mood and worsen the flu-like symptoms experienced during a keto diet.

Can You Rely on 'Sleep Water' to Regulate Sleep?

Make Sure to Eat Enough Carbs and Fat

Switching to a very low-carb diet plan may cause you to crave for things that are normally restricted on a keto diet. These may include pasta, bread, bagels, and cookies.

However, these cravings can be reduced by eating enough fat, the main source of fuel on a ketogenic diet. Research has proved that a low-carb diet itself can help reduce your cravings for high-carb foods such as sweets.

Slowly cut back on the carbs and increase the proteins and fat at the same time. This may help you make the transition more smoothly while avoiding all the flu-like symptoms.

Why do You Get the Keto Flu?

Different people adapt to the ketogenic diet differently. Some may experience the symptoms for weeks while others may adjust to this new dietary plan with no side effects at all.

These symptoms are usually tied to how their bodies are adjusting to their new fuel source.

Usually, carbohydrates provide energy to your body in the form of glucose. As soon as the carbs are reduced, the body starts burning ketones derived from fats instead of glucose.

RELATED: Ketogenic Diet- Lose Weight With Fats

People who tend to consume a lot of carbs, especially the refined ones such as sugary cereals, pasta, and soda may have to suffer from a more difficult time while initiating a ketogenic diet.

Hence, this transition from a regular diet to a high-fat, low-carb diet can prove to a struggle for some of you. Others, on the other hand, may find it easy to switch between the two fuel sources easily with little or no symptoms of the keto flu.

The reason why some of the people can adapt to a ketogenic diet more easily than others is not known. However, electrolyte loss, genetics, carbohydrate withdrawal, and dehydration are said to be some of the driving factors behind this keto flu.

Who Should Not Go for a Ketogenic Diet?

Despite the fact that a ketogenic diet is extremely helpful for losing weight, it may not be suitable for all the people.

For instance, it is not wise for pregnant or nursing mothers to follow. Children and teenagers must also refrain from this diet unless it is being monitored by a healthcare professional.

Additionally, people suffering from certain health problems such as liver disease, kidney disease, or pancreatic conditions may also need to avoid this dietary plan.

People suffering from diabetes must always consult a doctor prior to following this diet. This is to ensure if it is safe for them and suitable for their needs.

Lastly, it may not be wise for the patients with hypertension to observe a ketogenic diet. This is because this diet requires you to eat high amounts of fat which can negatively affect the health of these individuals.


The keto flu refers to a set of symptoms linked with your body adapting to a ketogenic diet. Some of the common symptoms of this condition include fatigue, headache, constipation, nausea, and sugar cravings. Replacing electrolytes, drinking enough water, and getting rest are some of the ways to reduce it.

Nancy Walker

Nancy holds a Medicine degree and a Masters of Science MS in Infectious Disease and Global Health (MS-IDGH) from Tufts University. She worked as a lecturer for three years before she turned towards medical writing. Her area of interest are infectious diseases; causes, mechanism, diagnosis, treatments and prevention strategies. Most of her writings ensure an easy understanding of uncommon diseases.

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