How To Avoid Keto Flu: What It Is, Symptoms, + 6 Fast Remedies

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As with many dietary adjustments or “illnesses“ in general, the symptoms of the keto flu can vary from individual to individual.

But, what is keto flu? What causes keto flu? How long does it last? What are the common keto flu symptoms? Is there a keto flu cure?

In this article, we will discuss what keto flu is, typical keto flu symptoms, and how to avoid keto flu with our very own keto flu remedies that can help you feel better fast.

We will cover: 

  • What Are the Common Keto Flu Symptoms?
  • How Long Does the Keto Flu Last?
  • How To Avoid Keto Flu With Keto Flu Remedies

Let’s dive in! 

A person holding their temples showing they have a headache.

What Are the Common Keto Flu Symptoms?

So, what is keto flu? As with all types of extreme dietary changes, when you switch to the keto diet, your body has to get used to digesting a totally different group of foods.

The keto diet has been shown to help support weight loss and improve insulin sensitivity, among other markers of health.

The ratio of nutrients causes the body to burn ketones for fuel rather than carbohydrates. This can cause a cluster of symptoms termed the “keto flu” or “carb flu.”

Keto flu symptoms can range from mild to severe, and studies suggest that the specific symptoms you experience will depend on your own biochemistry, as well as the previous diet that you are transitioning from.

People who seem to be most prone to developing keto flu symptoms are those that were following a high-carbohydrate diet and made a sudden and significant transition to the keto diet, essentially eliminating all carbohydrates.

Therefore, if you were already following a relatively low-carbohydrate diet, you may not suffer severe keto flu symptoms relative to someone who was following a plant-based, high-carbohydrate diet or diet that included a lot of starches, grains, and refined carbohydrates.

According to research, some of the common symptoms of the keto flu include diarrhea, nausea, headache, irritability, fatigue, weakness, stomach pain, muscle cramps, muscle soreness, brain fog, difficulty sleeping, hunger, food cravings, and dizziness.

A person holding their head with a headache.

How Long Does the Keto Flu Last?

Just as the specific symptoms of the keto flu vary from person to person, so too does the severity of these symptoms and how long the keto flu symptoms will last.

In most cases, keto flu symptoms linger for several days to several weeks after starting the keto diet.

Let’s dive into how to prevent keto flu symptoms as well as potential keto flu remedies you can employ to truncate the duration of the keto flu and decrease the severity of your symptoms.

How To Avoid Keto Flu With Keto Flu Remedies

There isn’t necessarily a “keto flu cure” or a way of how to avoid keto flu altogether, but there are various keto flu remedies or tips that can help reduce the symptoms of the keto flu.

Here are some tips for how to get rid of the keto flu and help your body get through the transition to the keto diet more smoothly:

A person drinking a glass of water.

#1: Drink More Water

It seems that almost every weight loss diet or health-related advice suggests drinking more water, so it is probably not surprising that a tip to drink more water appears on our list of tips to treat keto flu.

Drinking enough water can help reduce keto flu symptoms because the keto diet causes your body to rapidly release body water stores, which increases the risk of dehydration.

Because the keto diet is so low in carbohydrates, when you switch to the keto diet, your body quickly uses up your glycogen stores without them being readily replaced with new dietary carbohydrates you are taking in.

For every gram of glycogen that your body stores, about 3 to 4 grams of water are also stored. Thus, as you burn through your glycogen stores, this body water is released, and your body water drops.

This is the primary reason why people seek a rapid decrease in weight when first switching to the keto diet. The majority of this weight loss is not fat loss but rather a decrease in water weight.

Some of the symptoms of the keto flu are actually a result of dehydration itself, namely headaches, fatigue, brain fog, dizziness, and general malaise.

By increasing your water intake, you can help prevent keto flu symptoms by offsetting the increase in water loss and helping maintain optimal body water levels.

In terms of treating the keto flu, drinking enough water is also extremely important when you are experiencing keto diarrhea. 

Diarrhea further dehydrates the body because so much extra water is lost through loose stool, as the large intestines do not have enough time to re-absorb excess water from diarrhea stools.

A spoonful of electrolyte powder in a glass.

#2: Add Electrolytes

One of the best tips to prevent the keto flu and one of the most effective keto flu remedies is to increase your electrolyte intake.

Many of the keto flu symptoms are attributable to the rapid shift in electrolyte balance that can occur when switching to the keto diet.

When you transition to the keto diet, your pancreas releases a lot less insulin because your carbohydrate intake is so low. This causes the kidneys to release excess sodium, which is actually another reason why the keto diet is associated with dehydration early on. 

Sodium increases water retention, so as your body releases sodium, your water stores drop even lower, decreasing your water weight.

Furthermore, the keto diet eliminates a lot of foods that are naturally high in potassium, such as fruits, starchy vegetables like potatoes, beans, and other legumes. As such, your electrolytes can become imbalanced and depleted.

Consider adding electrolyte tablets or drinking electrolyte beverages for the first couple of weeks when you switch to the keto diet, and even ongoing if you are having a difficult time eating foods high in electrolytes that are still compatible with the keto diet.

You can also salt your food if you do not have hypertension or concerns with high blood pressure.

Many nuts are good sources of magnesium. Avocados are one of the best sources of potassium, and sodium can be found in cheeses, salted nuts, eggs, meat, poultry, and fish. Full-fat dairy also provides magnesium, potassium, and calcium.

A person walking at sunset.

#3: Lower the Intensity of Your Workouts

Many people adopt the keto diet as a way to lose weight, so the thought of needing to cut back on exercise may seem counterproductive.

However, if you are experiencing keto flu symptoms such as fatigue, muscle cramping, and headaches, it is a good idea to at least adjust your fitness routine to reduce the intensity of your workouts.

You can still move your body and engage in light exercise such as walking or low-intensity indoor cycling, but you might want to avoid strenuous exercise such as running, HIIT workouts, and strength training.

This will give your body time to adapt to the keto diet without further stressing your body with strenuous physical activity. Additionally, most people experience keto flu symptoms largely because of the sudden decrease in carbohydrate ingestion.

Carbohydrates are the primary and preferred fuel source for the muscles and the heart during high-intensity exercise.

Therefore, many people struggle with their workouts over the first couple of weeks when switching to the keto diet because you no longer have as much muscle glycogen and available blood sugar for your muscles. 

Although your body will adapt over time, it can be helpful to temporarily prioritize lower-intensity exercise. 

When you exercise at a lower intensity, the muscles are better able to use fat for fuel, so you will not only be able to perform the exercise more comfortably on the keto diet but there will be less of a risk of exacerbating keto flu symptoms by using up whatever glycogen and blood glucose you have available.

A person sleeping with a sleep mask on.

#4: Get More Sleep

You can combat keto flu symptoms, such as fatigue and irritability, by trying to get more sleep.

Insufficient sleep will also increase the levels of cortisol, a stress hormone, in your body. This, in turn, can depress your mood and make you more irritable, potentially exacerbating keto flu symptoms.

#5: Transition Gradually

Although many people like to dive all into the keto diet head first, transitioning gradually but progressively paring back your carbohydrate intake is one of the best ways of how to prevent keto flu.

Even just taking three or four days to incrementally cut back on the number of grams of carbohydrates you are eating per day can help prevent keto flu symptoms and guide your body through the transition to a very low-carb diet.

A serving board filled with avocado, nuts, fish and oil.

#6: Make Sure You Are Eating Enough Fat

Although not necessarily a keto flu cure, one important tip for adopting the keto diet is to make sure you are eating enough fat.

Although many people think of the keto diet as just a very low-carb diet (and it is), it is really designed to be a high-fat diet. You should be focusing on getting at least 70 to 75% of your calories from fat.

Studies have found that high-fat diets reduce the cravings for sugary foods, such as cookies, cakes, sweetened cereals, and other high-carb foods that your body might be accustomed to and craving when you start the keto diet.

Fat also improves satiety, helping keep hunger at bay.

Overall, the keto flu can be discouraging and may make you second-guess your decision to start the keto diet.

However, if you transition gradually to the keto diet and employ some of the tips for preventing the keto flu, you can decrease the severity of keto flu symptoms and your body’s adjustment to the keto diet.

For a long list of foods high in electrolytes to help avoid dehydration and an electrolyte imbalance while transitioning to the keto diet, check out our list here.

A woman drinking an electrolyte-filled sports drink.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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