Keto Flu Or Sickness: How To Tell The Difference

The keto flu is a group of symptoms that can occur within the first few days of starting a ketogenic diet, also known as the keto diet. The keto diet is a low-carb, high-fat diet intended to put the body into a state of ketosis, where it burns stored fat instead of glucose for energy. The keto flu is essentially the body's response to withdrawing from carbs, and symptoms can include nausea, dizziness, sugar cravings, muscle soreness, irritability, and constipation. While the keto flu is usually temporary and lasts for about a week, it can be uncomfortable and properly managing the symptoms is important.

Keto flu symptoms and their causes

The keto flu is a collection of symptoms that some people experience when they start a ketogenic diet. The symptoms, which can feel like the flu, are caused by the body adapting to a new diet that is very low in carbohydrates. The ketogenic diet is generally safe, but it can be associated with some unpleasant side effects.

Symptoms

• Stomach aches or pains: One of the most frequently reported symptoms of the keto flu is stomach pain.
• Nausea
• Dizziness
• Sugar cravings
• Cramping
• Muscle soreness
• Irritability
• Diarrhea or constipation
• Trouble falling asleep or staying asleep
• Poor focus and concentration
• Headache
• Fatigue

Causes

The keto flu is caused by the body's transition to a new fuel source. Usually, carbohydrates provide the body with energy in the form of glucose. When carbs are substantially reduced, the body switches to burning ketones from fat instead, leading to a state of ketosis. This transition can be challenging, especially for those who typically consume a lot of carbs.

The keto flu is also believed to be driven by genetics, electrolyte loss, dehydration, and carbohydrate withdrawal.

Duration

The keto flu typically lasts for a few days to several weeks, and in extreme cases, it can last up to a month.

Relief

To ease the symptoms of keto flu, it is recommended to:

• Stay hydrated by drinking plenty of water
• Replace electrolytes by adding more salt to your food or drinking sports drinks
• Get plenty of rest and avoid strenuous exercise
• Eat enough healthy fats and calories
• Gradually reduce your carb intake instead of an immediate and severe restriction

How long does the keto flu last?

The keto flu is a collection of symptoms that some people experience when starting a ketogenic diet. This occurs as the body adapts to a new diet consisting of very few carbohydrates. Symptoms can include nausea, dizziness, sugar cravings, muscle soreness, irritability, and trouble sleeping, and can range from mild to severe.

The keto flu usually lasts for a few days but can persist for several weeks, and in some cases, up to a month. The duration varies depending on the individual, with some people being naturally "metabolically flexible" and able to shift metabolic states easily without experiencing health symptoms.

If symptoms of the keto flu last longer than ten days, or are causing significant pain or debilitation, it is recommended to consult a doctor.

How to manage keto flu symptoms

The keto flu is a collection of symptoms that some people experience when they start a ketogenic diet. Symptoms include nausea, fatigue, muscle soreness, and cravings, and they can range from mild to severe. While the keto flu can be unpleasant, there are several ways to reduce its flu-like symptoms and help your body adjust to this new way of eating:

• Stay hydrated: Drink plenty of water to prevent dehydration, which is a common side effect of the keto diet as the body sheds water stores quickly.
• Replace electrolytes: Include more salt in your food and consider drinking sports drinks or taking supplements to replace lost electrolytes like sodium, potassium, and magnesium.
• Get enough rest: Avoid strenuous exercise, especially in the first week of the keto diet. Instead, focus on light activities like walking, yoga, or leisurely biking, and ensure you're getting enough sleep.
• Eat enough fat: Consume enough healthy fats and calories to reduce cravings and keep you feeling satisfied.
• Cut carbs slowly: If you're finding it difficult to adjust to the keto diet, try reducing your carb intake gradually over a few days or weeks instead of all at once.
• Eat more vegetables: Include a variety of non-starchy vegetables in your diet, such as spinach, leafy greens, broccoli, cauliflower, and Brussels sprouts. These foods are also rich in essential electrolytes.

Who should avoid the keto diet?

The keto diet is not suitable for everyone. Here are some groups of people who should avoid the keto diet:

Pregnant or Breastfeeding People

The keto diet may not be appropriate for pregnant or breastfeeding individuals unless it is being used therapeutically and under medical supervision. The diet may not provide enough protein for pregnant women, and the high-fat content may signal food scarcity to the body, which is not ideal during pregnancy.

Children and Teens

The keto diet is not recommended for children and teens unless prescribed and monitored by a healthcare provider, as it may cause nutritional deficiencies and disrupt the menstrual cycle of adolescent females.

People with Eating Disorders

The restrictive nature of the keto diet may trigger unhealthy patterns for those with active eating disorders or a history of disordered eating. This can negatively impact their health in both the short and long term.

People with Adrenal Fatigue

Low-carb diets have been shown to negatively affect cortisol levels, so the keto diet may be unsuitable for people with adrenal fatigue. More research is needed to confirm this.

People with Hypothyroidism

Some people with hypothyroidism who have adopted a keto diet report that their symptoms worsened. At least one study has indicated that a ketogenic diet can cause thyroid malfunctions in some people.

People with No Gallbladder or Gallbladder Disease

The keto diet requires a high intake of fat, and those without a gallbladder or with gallbladder disease may not have enough bile to break down these fats. This could lead to malnutrition or unpleasant symptoms.

People with a History of Gut Dysbiosis

The keto diet has been shown to alter gut flora and reduce the diversity of gut microbiota due to its very low intake of carbohydrates. This could be detrimental to those with a history of gut or digestive issues.

High-Performance Athletes

The keto diet may not provide sufficient calories or quick fuel from carbohydrates for competitive or high-performance athletes. Research shows that higher-carbohydrate diets are best for athletes.

People with Kidney Disease or Kidney Stones

The keto diet has been linked to an increased risk of kidney stones and could also be dangerous for those with kidney disease due to its high-fat content and potential impact on kidney function.

People with Liver Disease

The keto diet should be avoided by those with liver disease to prevent adverse effects on liver function.

People with Pancreatic Conditions

The keto diet is not safe for those with any conditions involving their pancreas.

People with Diabetes

Diabetics interested in the keto diet should consult their doctor to determine if it is safe and suitable for their specific needs.

Individuals with a History of Heart Disease

The keto diet has been associated with an increased risk of heart disease due to its potential to increase cholesterol levels.

How to prevent keto flu

The keto flu is a collection of symptoms experienced by some people when they start a ketogenic diet. It is not actually the flu and is not contagious, but it can feel similar. The symptoms are caused by the body adapting to a new diet consisting of very few carbohydrates.

• Drink more water — The keto diet can cause you to lose water rapidly, increasing the risk of dehydration. Staying hydrated can help with symptoms like fatigue and muscle cramping.
• Replace electrolytes — When following a ketogenic diet, insulin levels decrease, causing the kidneys to release excess sodium from the body. Getting adequate electrolytes is an excellent way to power through the adaptation period. Salting food to taste and including potassium-rich, keto-friendly foods like leafy greens and avocados are recommended.
• Get enough sleep — 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 impact mood and make keto-flu symptoms worse.
• Eat more fat and calories — Transitioning to a very low-carb diet can cause you to crave restricted foods. Eating enough fat, the primary fuel source on the ketogenic diet, will help reduce cravings and keep you feeling satisfied.
• Consider a slower transition — Many of the symptoms of keto flu are the result of a sudden dietary shift. Reducing your carb intake over a few days or weeks can help your body adjust to your new diet naturally and without the negative symptoms of carb flu.

Frequently asked questions