Keto Flu: Understanding The Duration And Impact

The keto flu is a group of symptoms that may appear two to seven days after starting a ketogenic diet. Symptoms can vary from person to person, but typically include headache, fatigue, nausea, and dizziness. While the keto flu can make you feel miserable, it is not a cause for concern. The symptoms will usually go away within the first week or two of starting the diet, but they can sometimes last up to a month. Staying hydrated and replacing lost electrolytes are important steps to take to reduce the symptoms of keto flu.

Keto flu symptoms

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The ketogenic diet is very low in carbohydrates, high in fat, and moderate in protein. The intention is to put your body in a state of ketosis, where it burns stored fat instead of glucose.

Symptoms of the keto flu can vary but typically include:

• Headaches
• Fatigue
• Muscle cramps
• Body weakness
• Body aches
• Low energy
• Sugar cravings
• Irritability
• Lightheadedness
• Brain fog
• Nausea
• Constipation
• Diarrhea
• Dizziness
• Decreased energy
• Feeling faint
• Heartbeat alterations
• Stomach or intestinal pain
• Sleep issues

These symptoms are caused by the body adapting to a new diet consisting of very few carbohydrates. This drastic reduction can come as a shock to the body, which may need time to adjust to this new way of eating.

The keto flu is usually temporary and tends to go away within the first week or two of starting the diet. However, for some people, symptoms may last up to a month.

If you are experiencing keto flu symptoms, there are several things you can do to alleviate them:

• Stay hydrated: Drink plenty of water to prevent dehydration, which can worsen symptoms.
• Replace electrolytes: Electrolyte imbalances can cause many keto flu symptoms. Bone broth, sports drinks, or electrolyte powders can help correct these imbalances.
• Eat more fat and calories: Ensure you are eating enough fat and calories to curb cravings and hunger.
• Adjust your diet gradually: If you are finding it difficult to adjust, try reducing your carb intake gradually over a few days or weeks instead of all at once.
• Get enough rest: Avoid heavy exercise during the first week and allow your body to rest and adjust to the new diet.

How long does keto flu last?

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 diet forces the body to burn ketones for energy instead of glucose, which is known as ketosis.

The keto flu can cause symptoms such as fatigue, nausea, headaches, muscle soreness, and cravings, which can feel similar to an influenza virus. The keto flu is not an infection, however, and does not trigger an immune response or a fever.

The keto flu typically lasts for a few days or up to several weeks. Most people experience symptoms within the first week of starting the diet, which usually peak within the first seven days and then steadily improve over the course of the first month. For some people, symptoms may last up to a month.

The duration of the keto flu depends on several factors, including metabolic flexibility, age, genetics, current body weight, and lifestyle habits. It is also important to stay hydrated and replenish electrolytes during this time, as the keto diet can lead to a rapid loss of body water and sodium.

What causes keto flu?

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. The symptoms can include headaches, fatigue, weakness, irritability, muscle cramps, insomnia, nausea, and constipation.

The exact causes of the keto flu are not fully understood, but it appears to be the result of the body's transition from a carb-fuelled diet to a fat-fuelled one. This transition involves significant changes in the body's metabolic state, including a shift from burning glucose to burning ketones for energy. Here are some of the specific causes of the keto flu:

Sodium Deficiency

When you minimise carbs, you also minimise insulin, a hormone that tells your kidneys to retain sodium. With less insulin, your body excretes more sodium through urine. As sodium is essential for nerve impulses, fluid balance, and hormone regulation, its deficiency can lead to keto flu symptoms like headaches, muscle cramps, weakness, brain fog, insomnia, and irritability.

Dehydration and Overhydration

The keto diet can lead to dehydration because your body starts to break down glycogen, which is stored with water. This results in water loss, and if not properly managed, can lead to dehydration. However, overhydration can also be an issue, as drinking too much water can dilute blood sodium levels, exacerbating low sodium symptoms.

Carb Withdrawal

Carbs and sugar activate reward pathways in the brain, so eliminating them can lead to carb cravings and "withdrawal" symptoms. Sugar can trigger a release of dopamine, similar to addictive drugs, so depriving yourself of carbs can result in a lack of dopamine-driven good feelings. This can cause symptoms like hunger, carb cravings, mood fluctuations, low energy, headaches, and fatigue.

Reduced Brain Fuel

When you reduce your carb intake, your brain has to transition from using carbs and glucose to using fat and ketones for fuel. This transition can take some time, and during this period, cognition-related keto flu symptoms such as headaches, brain fog, low energy, and fatigue may occur.

Electrolyte Loss

When insulin levels decrease during the keto diet, the kidneys release excess sodium, leading to a loss of electrolytes. This electrolyte imbalance can cause symptoms such as fatigue, muscle cramps, and body weakness.

Increased B Vitamin Requirements

Using fat as a fuel source requires different metabolic pathways than burning sugar, and efficient ketosis relies on good levels of B vitamins. Therefore, a dip in B vitamin levels can result in keto flu symptoms like body aches, low energy, and sugar cravings.

How to get rid of keto flu

The keto flu is a collection of symptoms experienced by some people when they first start a ketogenic diet. The symptoms can vary from mild to severe and include fatigue, muscle cramps, headaches, nausea, constipation, and cravings. The good news is that the keto flu is temporary and usually lasts only a few days to a couple of weeks. Here are some ways to get rid of the keto flu:

• Stay hydrated: Drink plenty of water to prevent dehydration, which can worsen keto flu symptoms.
• Replace electrolytes: Include more salt in your food or drink sports drinks that are high in electrolytes. Bone broth is also a good option, as it is naturally high in electrolytes and stimulates bile production, supporting fat digestion and absorption.
• Eat more fat and calories: Ensure you are consuming enough healthy fats and calories to curb cravings and hunger.
• Eat nutrient-dense, high-quality foods: Include plenty of green leafy vegetables, avocado, nuts, seeds, pork, seafood, and full-fat dairy in your diet. These foods are rich in B vitamins, which are essential for fat burning.
• Adjust your exercise routine: Avoid high-intensity exercises until your body is fully keto-adapted. Opt for lighter forms of exercise such as walking, yoga, or swimming.
• Consider a slower transition: If the keto flu is making it difficult to stick to the keto diet, you can gradually reduce your carb intake over a few days or weeks instead of immediately and severely limiting it.

Who is likely to get keto flu?

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

The keto flu is likely to happen to those who drastically and suddenly remove carbs from their diet. The body burns carbohydrates (glucose) for energy by default, so switching to a fat-burning process can confuse your body. When the carb intake is drastically reduced, the body is depleted of stored glucose and instead turns to burning fatty acids for energy. This metabolic process is called ketosis.

The keto flu is not exclusive to everyone who embarks on the keto diet. Some people are naturally "metabolically flexible", meaning they can shift metabolic states easily without experiencing health symptoms. Your risk of keto flu symptoms depends on your metabolic flexibility. Your age, genetics, current body weight, and lifestyle habits influence how quickly your metabolism can shift into fat-burning mode.

The keto flu is caused by dehydration and electrolyte loss, increased B vitamin requirements, and carbohydrate withdrawal.

Symptoms of the keto flu include:

• 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
• Brain fog
• Headaches
• Fatigue

The keto flu can last from a few days to several weeks, and in extreme cases, up to a month.

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