Keto Flu: Why Some People Avoid It

The keto flu is a collection of symptoms that some people experience when they start a ketogenic diet. The ketogenic diet is very low in carbohydrates, high in fat, and moderate in protein. The keto flu is not an actual flu, but the symptoms are similar, including headache, fatigue, body aches, dizziness, and nausea. These symptoms are caused by the body adapting to a new diet consisting of very few carbohydrates. The keto flu can last from a few days to a few weeks, and in some cases, even up to a month. However, not everyone experiences the keto flu when starting a ketogenic diet. Some people may transition to the diet without any side effects.

Keto flu is not influenza

The keto flu is not influenza. It is a set of symptoms that some people experience when starting a ketogenic diet. The ketogenic diet is very low in carbohydrates, high in fat, and moderate in protein. This drastic reduction in carbohydrates can come as a shock to the body and cause withdrawal-like symptoms. The keto flu is not a recognised medical condition, and you will not develop a fever or feel incapacitated. However, it can cause a range of mild to severe symptoms, including:

• Stomach aches or pains
• Nausea
• Dizziness
• Sugar cravings
• Cramping
• Muscle soreness
• Irritability
• Diarrhea or constipation
• Trouble falling asleep or staying asleep
• Poor focus and concentration
• Headache
• Fatigue

The keto flu is believed to be caused by the body's adjustment to a new fuel source. Typically, the body uses carbohydrates (glucose) for energy. When carb intake is reduced, the body switches to burning ketones from fat instead, a process called ketosis.

The keto flu usually lasts for a few days to several weeks, but in some cases, it can last up to a month. To reduce the symptoms of the keto flu, it is recommended to:

• Stay hydrated by drinking plenty of water
• Replace lost electrolytes with salts, potassium, and magnesium
• Get enough rest
• Avoid strenuous activities
• Eat enough fat and carbohydrates
• Cut out carbs slowly over time

Symptoms of keto flu

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The symptoms are caused by the body adapting to a new diet consisting of very few carbohydrates. The symptoms of keto flu can range from mild to severe and vary from person to person.

Some of the most frequently reported symptoms of keto flu are:

• Stomach aches or pains
• Nausea
• Dizziness
• Sugar cravings
• Cramping
• Muscle soreness
• Irritability
• Diarrhea or constipation
• Trouble falling asleep or staying asleep
• Poor focus and concentration
• Fatigue
• Headaches
• Brain fog

These symptoms are usually temporary and typically last a few days to several weeks. However, in extreme cases, they can last up to a month or more.

If you're experiencing keto flu symptoms, there are several ways to manage and reduce them:

• Stay hydrated: Drink plenty of water to prevent dehydration, which can be a side effect of the keto diet.
• Replace electrolytes: Add electrolytes like salts, potassium, and magnesium to your diet, or drink sports drinks.
• Get plenty of rest: Avoid strenuous exercise and focus on lighter activities such as walking or yoga.
• Adjust your diet: Ensure you're consuming enough healthy fats and calories. Gradually reduce your carb intake over a few days or weeks to ease the transition.

Causes of keto flu

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The symptoms are caused by the body adapting to a new diet consisting of very few carbohydrates. The ketogenic diet is very low in carbohydrates, high in fat, and moderate in protein.

The keto flu is believed to be caused by a combination of factors, including:

Carbohydrate Withdrawal

The sudden reduction or elimination of carbohydrates from the diet can lead to withdrawal-like symptoms. Carbohydrates are the body's main source of energy, and when they are restricted, the body has to adjust to using fat as fuel. This can be a challenging transition for the body, leading to flu-like symptoms.

Electrolyte Loss

The keto diet restricts many foods that are rich in electrolytes, such as fruits, beans, and starchy vegetables. This can lead to an imbalance in electrolytes, particularly sodium, potassium, and magnesium, which are important for maintaining proper bodily functions.

Dehydration

The keto diet can cause a rapid loss of water stores in the body, leading to dehydration. This is because carbohydrates bind to water in the body, so when carbohydrate intake is reduced, water is excreted. Dehydration can exacerbate other symptoms and make the transition more difficult.

Genetics

It is believed that genetics may play a role in an individual's susceptibility to keto flu. Some people may be naturally "metabolically flexible," meaning they can easily shift between different metabolic states without experiencing negative symptoms.

Gut Microbiome Changes

The keto diet may also impact the gut microbiome, as it involves a significant change in the types and amounts of food consumed. This change in gut bacteria could be a contributing factor to the keto flu symptoms.

Treatment of keto flu

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The symptoms, which can feel similar to the flu, are caused by the body adapting to a new diet consisting of very few carbohydrates.

• Stay hydrated: The keto diet can cause a rapid loss of water stores, increasing the risk of dehydration. Drinking plenty of water can help reduce symptoms such as fatigue and muscle cramping.
• Replace electrolytes: The keto diet restricts many foods that are high in potassium, such as fruits, beans, and starchy vegetables. Adding more salt to your food, drinking sports drinks, or taking supplements can help your body maintain a healthy balance of electrolytes and reduce symptoms.
• Get enough rest: Fatigue and irritability are common complaints when adapting to a ketogenic diet. Lack of sleep can increase levels of the stress hormone cortisol, which can negatively affect mood and worsen keto flu symptoms. Taking an Epsom salt bath or drinking herbal tea can help promote better sleep.
• Avoid strenuous exercise: While exercise is important for overall health, it's best to avoid intense workouts during the keto flu. Light activities such as walking, yoga, or leisurely biking may help improve symptoms.
• Eat enough fat: Transitioning to a very low-carb diet can cause cravings for restricted foods. Eating enough healthy fats can help reduce cravings, improve energy levels, and aid in the transition to burning fat for fuel.
• Cut out carbs slowly: Gradually reducing carbohydrate intake over a few days or weeks can help your body adjust to the new diet and minimise keto flu symptoms.

Prevention of keto flu

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The symptoms can feel similar to the flu and are caused by the body adapting to a new diet consisting of very few carbohydrates.

Stay hydrated

Drinking enough water is necessary for optimal health and can also help reduce keto flu symptoms. A keto diet can cause a rapid loss of water, increasing the risk of dehydration. Staying hydrated can help with symptoms like fatigue and muscle cramping. Replacing fluids is especially important when experiencing keto-flu-associated diarrhoea, which can cause additional fluid loss.

Replace electrolytes

Replenishing electrolytes may help reduce keto-flu symptoms. When following a ketogenic diet, insulin levels decrease, causing the kidneys to release excess sodium from the body. The keto diet also restricts foods that are high in potassium, such as fruits, beans, and starchy vegetables. Getting adequate amounts of these nutrients can help power through the diet's adaptation period. Salting food and including potassium-rich, keto-friendly foods like leafy greens and avocados are excellent ways to maintain a healthy balance of electrolytes.

Get enough rest

Fatigue and irritability are common complaints when adapting to a ketogenic diet. Lack of sleep causes levels of the stress hormone cortisol to rise, which can negatively affect mood and worsen keto-flu symptoms. Taking an Epsom salt bath can help soothe and relax muscles, as well as improve electrolyte absorption. Drinking keto-friendly herbal tea with calming herbs can also promote deeper sleep.

Avoid strenuous activities

While exercise is important for maintaining health and weight, strenuous exercise should be avoided when experiencing keto-flu symptoms. Fatigue, muscle cramps, and stomach discomfort are common in the first week of following a ketogenic diet, so it may be advisable to rest. Light activities like walking, yoga, or leisurely biking may improve symptoms.

Eat enough fat and cut out carbs slowly

Transitioning to a very low-carb diet can cause cravings for restricted foods. Eating enough fat, the primary fuel source on the ketogenic diet, will help reduce cravings and increase satisfaction. Research shows that low-carb diets help reduce cravings for sweets and high-carb foods. Gradually reducing carbohydrate intake while increasing fat and protein intake may make the transition smoother and decrease keto-flu symptoms.

Frequently asked questions