How To Prevent The Keto Flu: Symptoms And Remedies

  • Post last modified:August 11, 2021
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In recent years, the ketogenic diet has become more popular due to its obvious weight loss effects and overall health benefits. 

The main feature of the ketogenic diet is that the body enters a metabolic state called ketosis through a very low carbohydrate and a high proportion of fat intake, which is more effective to burn fat.

This type of diet is safe for most people, but there are also many people who experience some physical discomfort when they first enter a Ketosis state. This is called the “keto flu” which is caused by changes in a person’s diet.

Due to these adverse reactions or side effects, many people are reluctant to use a ketogenic diet or are unable to stick to it.

However, if you understand the symptoms and remedies of keto flu and know how to prevent them, you can lessen any discomfort and more quickly begin to truly experience the benefits of a ketogenic diet.

What Is Keto Flu 

Keto flu is not the real flu, and it is not contagious. It is similar to the common cold or flu in symptoms.

Generally speaking, this flu-like feeling happens in the first week of beginning a keto diet. It improves and disappears as the body gradually adapts to the new diet.

With a traditional diet, our body is used to burning glucose as an energy source. The main source of glucose is carbohydrates.

The strict control of carbohydrate intake in the ketogenic diet will reduce the body’s insulin level.

When the insulin reaches a certain level, the liver begins to convert fat into acids called ketones. At this time, your body will mainly use ketones and fats to provide energy.

This conversion process is called ketosis. In other words, ketosis refers to the metabolic state in which the body converts stored fat into energy, releasing ketones in the process.

Ketosis doesn’t only  occur in a ketogenic diet. It also can happen when you fast, which can also help your body enter a state of ketosis.

When insulin levels decrease, your body also responds by increasing sodium and water in the urine.

Thus, in the first week or so of a ketogenic diet, you will find that you urinate more frequently. You will also be pleasantly surprised to see a very significant weight loss, most of which is water loss.

If your carbohydrate intake is not enough to meet the body’s demand for glucose metabolism, which then turns to fat metabolism, this drastic change will have an impact on the body. Your brain will also need time to adapt and use this new fuel.

Imagine what physical reactions occur when a person who is addicted to caffeine suddenly stops drinking coffee, or a drug addict receiving detoxification treatment. When thinking about beginning a keto diet in those terms, it is easy to understand why ketosis causes a series of discomforts.

What Are The Symptoms Of The Keto Flu

Completely changing your diet, especially by drastically reducing carbohydrate intake, is a very significant change for your body.

Many people experience different levels of adverse reactions during the transition period, especially in the first week.

The most common symptoms of keto flu are:

  • nausea
  • vomit
  • diarrhea or  constipation
  • headache
  • dizziness
  • fatigue
  • emotional instability,
  • apathy
  • muscle cramps or muscle aches
  • hair loss
  • bad breath
  • difficulty falling asleep
  • craving for sweets
  • a small number of people develop keto rash

The possible symptoms listed above generally do not appear at the same time. The adaptability to this process varies from person to person. Additionally, the length of the adverse reaction time varies as well.

Some people may not feel very much discomfort at all, while others may experience more diverse and more severe symptoms.

Those who are accustomed to eating a high-carbohydrate, high-sugar diet may encounter more difficulties when they first switch to a ketogenic diet. The adverse reactions may also be more serious.

How To Get Rid Of Keto Flu

Although the duration of keto flu symptoms does not last very long, usually the situation will lessen or disappear within a week or so. This process may be more difficult for some and less difficult for others.

However, by taking some measures to reduce the symptoms, you can pass this period more easily and smoothly.

1. Drink plenty of water and increase salt intake

In the early stages of a ketogenic diet, your body will lose a lot of water and salt, which is also one of the causes of keto flu.

When you have headaches, dizziness, nausea, muscle cramps, or other symptoms, drinking a glass of salt water may relieve the discomfort within 15-30 minutes.

When the symptoms of diarrhea occur, supplementing water and salt can effectively replenish the electrolytes lost by the body.

Enough water, sodium, and other electrolytes can also help relieve constipation, which is another problem often encountered in the early stages of a ketogenic diet. 

In addition, chicken broth, bone broth, etc. are also helpful.

2. Consume more good fats

Supplementing enough water and salt can effectively alleviate most of the symptoms of keto flu. However, if you still feel unwell, it is recommended that you increase your intake of healthy fats.

With the sudden change from a high-carb diet to a low-carb diet, you may experience fatigue and other symptoms. This is because there is not enough glucose to supply energy. Therefore, your brain will think that your body is starving. 

The intake rate of healthy fat in the ketogenic diet is as high as 70-75%. Eating more fat can reduce hunger, extend the interval between meals (fasting time) and help your body to convert to fat metabolism.

Once you adapt to this diet, your appetite will decrease and your body will burn and use stored fat for energy.

On the other hand, eating a very low-carbohydrate diet can lead to cravings for sweets and refined carbohydrates. In the early stages of the ketogenic diet, eating enough healthy fats can reduce this craving.

3. Avoid strenuous exercise

One of the health benefits of a ketogenic diet is to enhance physical strength and endurance. In the early stage, mainly in the first week, when the body has not fully converted to fat metabolism, fatigue, muscle cramps, and stomach discomfort is very common. During this period, continued strenuous exercise can aggravate the symptoms of keto flu.

It is best to focus on low-volume aerobic exercise during this time, like walking or yoga.

Your body is going through the process of converting sugar metabolism to fat metabolism. During this time, the stress is already high enough, so try not to increase the extra burden on the body by trying any strenuous exercise. You can gradually increase the amount of exercise after the symptoms are alleviated.

4. Replenishing dietary electrolytes

As mentioned above, the level of insulin in the body will decrease in the early stage of beginning a ketogenic diet. This causes the kidneys to release more sodium excreted in the urine.

A ketogenic diet also restricts many foods high in potassium, including fruits such as bananas, beans, and starchy vegetables.

Potassium is an essential nutrient element for the human body. Its deficiency can cause nausea, vomiting, abdominal distension, dizziness, fatigue, and other symptoms.

Therefore, getting enough food containing potassium during the hyper-eating period can effectively alleviate the discomfort caused by keto flu.

Foods rich in potassium in a ketogenic diet include green leafy vegetables, avocado (avocado) and sauerkraut, just to name a few. Thus, eating more of these foods can ensure an electrolyte balance.

These foods are also high in magnesium, which helps reduce muscle cramps, sleep problems, and headaches.

5. Ensure adequate sleep

Tiredness and restlessness are common problems in the early stages of a ketogenic diet.

Lack of sleep can increase the level of the stress hormone cortisol in the body. This has a negative impact on mood and aggravates the symptoms of ketone flu[*].

If you have sleep problems, like difficulty falling asleep or you cannot stay in a deep sleep, you can try the following methods:

  • do not watch intense movies or TV before going to bed;
  • drink less coffee or tea during the day;
  • ensure regular work and rest time;
  • don’t overeat, especially stop eating three hours before going to bed; 
  • take a hot bath to help you sleep;
  • keep the bedroom environment quiet. Cut off any light sources, including mobile phones, computers and TV;
  • meditation before going to bed can relax the spirit and improve sleep quality.

Some people who normally sleep well may have varying degrees of sleep issues when beginning a keto diet. Difficulty falling asleep or waking up easily after falling asleep are some of these issues.

However, like other symptoms of keto flu, this condition is only temporary. When your body is fully adapted to the new diet, the quality of your sleep should be restored or can even be better.

6. Gradually reduce carbohydrate intake

People who are accustomed to a traditional high-low-fat diet will find it more difficult to completely change their diet when beginning a keto diet. The adverse reactions may also be more serious.

However, the keto flu will not last long. When your body begins over-burning for energy, these symptoms will alleviate or disappear.

If you don’t want to experience too much physical discomfort, you can gradually reduce your carbohydrate intake to gradually adapt to a low-carb diet.

For example, begin by reducing from 200 grams of carbohydrates per day to 100 grams. Try that for a week. Then reduce it to 50 grams and keep it for a while.

In this way, your body will gradually adapt to the new diet structure. It will be a more gentle process.

When you feel that you are more used to the new eating habits, you can try to eat fewer carbs until you find the amount that suits you.


The adverse reactions and side effects of the ketogenic diet are normal. They will gradually disappear as the body adapts to this new eating habit.

Although there are many benefits, not everyone is suitable for a ketogenic diet. For example, pregnant women, breastfeeding women and children, adolescents in the growth and development period and people getting treatment for specific diseases, should begin a new diet under the supervision and guidance of a doctor, as should anyone changing their eating habits.

In addition, people with kidney disease, liver disease, pancreatic disease and people allergic to cholesterol are not suitable for a ketogenic diet.

In addition, a ketogenic diet or a low-carb diet is a healthy diet that can minimize your body’s inflammation and reduce the risk of inflammatory diseases.

Is the ketogenic diet unsafe? Be alert to these risks.

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