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Article: Keto Flu Effects: What Are They and How to Soften Them?

Maria Torres

Dietista y nutricionista especializada en salud hormonal y nutrición deportiva y evolutiva. @maria.torres_nutricions


When we start the ketogenic diet we can experience a series of symptoms similar to flu symptoms, called keto flu or ketoflu. These symptoms may include fatigue, a feeling of weakness, headaches, irritability, constipation, lack of concentration, nausea and even muscle cramps.

These symptoms usually appear between the second and fifth day after starting the diet. They usually disappear in about a week, leaving us even better than before.

Keto flu appears because the body stops using glucose as its main energy source and starts using fats. The modern Western diet is quite high in carbohydrates, so we have lost our ability to use fat as fuel. Our metabolic flexibility and the detoxification of excess carbohydrates and sugars are responsible for the appearance of these side effects.

In addition, this fuel change also produces a massive loss of water and certain minerals. Replacing them will be necessary to mitigate these types of symptoms.

What can we do to soften the effects of the keto flu?

1.- Hydration

The first thing we should do is hydrate ourselves. By this we don't just mean drinking more water than usual . Correct hydration involves the intake of minerals such as sodium, potassium or magnesium.

  • You can add these minerals to water in the form of supplements. Although the best recommendation is to drink isotonic seawater , since it contains all the necessary trace elements and in the appropriate proportions that our body needs. In fact, our blood plasma is very similar to seawater. You can also add half a teaspoon of sea salt to a glass of water and drink it as is.
  • As for magnesium , it would be highly recommended to supplement, since it is very difficult to consume it with food. Nowadays, the fertilizers used in the cultivation of many fruits and vegetables do not contain magnesium, which is why there is a deficit of this mineral in the population.
  • Another option is to consume bone broth , as it contains a high mineral content, as well as gelatin , glutamine , and vitamins .
  • Finally, you can eat foods rich in potassium , such as avocado.
2.- Fat consumption

Increase fat consumption. A good supply of fats will help a good transition to the fuel change. MCT or even coconut oil contain medium chain triglycerides, making them metabolized much faster in the liver. Other sources of suitable fats are butter or ghee, olive oil , avocado or olives , as well as fattier cuts of meat and oily fish .

3.- Moderate exercise

Don't overdo it with physical exercise. During the transition period to the keto diet, it is best to prioritize low-intensity exercises , such as walking, yoga or Pilates. During the change in diet our cortisol levels can increase, which is why we can feel more irritable. Further increasing cortisol with high-intensity exercise can aggravate these symptoms.

4.- Sleep and rest

During this transition period it is essential to sleep at least 8 hours to help the body recover and reduce accumulated cortisol levels.

5.- Progressive transition towards ketosis

Go little by little and don't restrict your calories. If you come from a diet very high in carbohydrates, it is recommended to make a slower transition to ketosis, reducing carbohydrate intake. Start with a low carb diet to gradually enter ketosis so that cortisol levels do not rise excessively. Something similar happens if we radically restrict calorie intake.

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