Keto Flu Headaches: What's The Real Deal?

The keto diet is a popular eating pattern that involves drastically reducing your carbohydrate intake and replacing it with fat. While this diet is effective for weight loss, it often comes with some unpleasant side effects, commonly known as the keto flu. One of the most common symptoms of the keto flu is headaches, which typically occur when you're starting the diet. So, are headaches part of the keto flu? Yes, they certainly can be.

Low blood sugar

The keto diet is a low-carb, high-fat diet that puts the body into a metabolic state called ketosis, where fat is burned as the primary source of energy instead of glucose. While this diet is popular for weight loss, it often comes with some uncomfortable side effects, including headaches, muscle cramps, constipation, fatigue, and dizziness, collectively known as the keto flu.

One of the main causes of keto headaches is low blood sugar, or hypoglycemia. When you start the keto diet, your body begins relying on ketone bodies instead of glucose, which can cause your blood sugar levels to drop. This transition into ketosis may stress your brain, resulting in mental fatigue or brain fog, as well as headaches.

To treat or prevent keto headaches caused by low blood sugar, it is important to:

• Drink plenty of water
• Get more sodium, potassium, and magnesium in your diet
• Avoid intense workouts, as they can lead to more stress on your body and may cause headaches
• Plan low-carb, nutrient-dense meals to ensure you are getting enough fat and energy
• Consult a healthcare professional if your headaches persist beyond a few days or weeks

While the keto diet can be an effective tool for weight loss, it is important to be aware of potential side effects such as keto headaches and take the necessary precautions to prevent and treat them.

Dehydration

When transitioning to a low-carb diet, the body enters a state called ketosis, where the liver releases ketones as an alternative energy source. This metabolic shift can cause an increase in urination, leading to dehydration if not properly managed. The keto diet's diuretic effect is driven by low insulin levels, which signal the kidneys to excrete more water. Additionally, the breakdown of glycogen, a stored form of carbohydrates, releases water, further contributing to fluid loss.

The keto diet also impacts hydration by affecting electrolyte balance. Electrolytes like sodium, potassium, and magnesium play a crucial role in maintaining hydration. However, the keto diet can lead to a depletion of these key electrolytes through increased urination and reduced intake from certain food sources. For example, a clean keto diet contains limited sodium and restricts potassium-rich foods like fruits and potatoes.

To prevent dehydration on the keto diet, it is essential to focus on both fluid intake and electrolyte balance:

• Drink adequate fluids: While staying hydrated is crucial, simply drinking more water is not always the solution. Over-hydration can dilute blood sodium levels, leading to a condition called hyponatremia, which has symptoms similar to keto flu. Instead, the recommendation is to drink to thirst, ensuring you consume enough water without overdoing it.
• Consume enough electrolytes: Sodium and potassium are particularly important. Liberal use of salt can help increase sodium intake, and eating leafy greens, nuts, and meats can boost potassium levels. In some cases, electrolyte supplements may be beneficial.

By addressing both fluid intake and electrolyte balance, individuals on the keto diet can effectively prevent dehydration, reducing the risk of keto flu symptoms, including headaches.

Electrolyte imbalance

The keto diet can lead to an electrolyte imbalance, which in turn can cause headaches. Electrolytes are minerals that carry an electric charge and are vital for the proper functioning of your body. The most common electrolyte imbalance is hyponatremia, or low sodium levels, which can cause muscle cramps and is one of the symptoms of keto flu.

When you start the keto diet, your body begins to rely on ketone bodies instead of glucose, which can cause your blood sugar levels to drop. This transition into ketosis may stress your brain, which could result in mental fatigue, or brain fog, as well as headaches.

Additionally, the keto diet has a diuretic effect, causing you to urinate more frequently. This can lead to dehydration, which is another common cause of headaches. Dehydration is exacerbated by the fact that your body produces less insulin on the keto diet, which can affect electrolytes such as potassium and sodium, which play key roles in hydration.

To treat and prevent keto headaches caused by electrolyte imbalances, you can:

• Drink plenty of water.
• Eat more low-carb, water-rich foods such as cucumbers, zucchini, lettuce, celery, cabbage, and raw tomatoes.
• Eat more electrolyte-rich foods such as avocados, spinach, mushrooms, and tomatoes, which are high in potassium.
• Add more salt to your food to reduce the risk of an electrolyte imbalance.
• Try an electrolyte supplement to minimise the risk of dehydration and keto flu symptoms.

Sodium, Potassium, and Magnesium

When levels of key electrolytes like sodium, potassium, and magnesium are low, it's important to replenish them. Water is essential for staying hydrated, but you also need to replenish your electrolytes through the food you eat or with an electrolyte supplement.

Sodium

Sodium is the most important electrolyte to replenish, with a daily intake of 5000-7000mg recommended. You can add more salt to your food or drink, or try a sugar-free and keto-friendly electrolyte drink.

Potassium

Potassium is the second most important electrolyte, with a recommended daily intake of 1000-3500mg. Good dietary sources of potassium include spinach, avocados, mushrooms, salmon, steak, pork loin, and lite sodium chloride.

Magnesium

Magnesium is also necessary to incorporate into your diet, with a recommended daily intake of 300-500mg. Good dietary sources of magnesium include spinach, avocados, magnesium aspartate, magnesium lactate, magnesium threonate, and magnesium citrate.

Preventing Electrolyte Imbalance

To prevent electrolyte imbalances on the keto diet, it is important to drink enough water and consume enough electrolytes. You can also try slowly transitioning into the keto diet, giving your body time to adjust to the new way of eating.

Keto Flu

The keto flu is a group of symptoms that can occur within the first few weeks of beginning the keto diet, including headaches, fatigue, brain fog, increased cravings, muscle cramping, thirst, diarrhea, and constipation. These symptoms are typically caused by dehydration and electrolyte imbalances, so ensuring proper hydration and electrolyte intake is key to preventing and treating them.

Stress and sleep deprivation

The keto diet is a significant dietary shift that involves reducing carbohydrate intake and increasing fat consumption. This change can be stressful for the body and mind, as it adjusts to a new way of eating and fuel source. Carbohydrates are the body's preferred source of energy, and when their intake is restricted, the body enters a state of ketosis, burning fat for energy instead. This transition to ketosis can be challenging, and the resulting metabolic changes can lead to what is known as the "keto flu."

The keto flu is characterised by a range of flu-like symptoms, including headaches, brain fog, fatigue, irritability, nausea, and difficulty sleeping. These symptoms typically arise within the first few days to a week of starting the keto diet and can last for several days to weeks. While not everyone experiences the keto flu, it is a common occurrence for many individuals.

To manage stress and sleep deprivation while on the keto diet, it is essential to prioritise self-care and adopt healthy lifestyle habits. Here are some strategies to consider:

• Get adequate sleep: Establish a consistent sleep schedule by waking up and going to bed at the same time each day. Reduce caffeine intake, especially in the latter part of the day, as it can interfere with sleep. Create a relaxing bedtime routine by minimising screen time before bed and engaging in soothing activities such as reading or listening to calming music.
• Manage stress: Incorporate stress-reducing techniques such as meditation, deep breathing exercises, or yoga into your daily routine. Physical activity, such as light walking or leisure biking, can also help reduce stress levels. Additionally, focus on consuming nutrient-rich foods and staying well-hydrated, as this can positively impact stress management.
• Gradual transition: Instead of abruptly eliminating carbohydrates, consider gradually reducing your intake over time. This slower approach may help your body and mind adjust to the new diet more comfortably and potentially reduce the intensity of headaches and other keto flu symptoms.
• Electrolyte balance: Ensure you are consuming adequate electrolytes, particularly sodium, potassium, and magnesium. These minerals are crucial for maintaining proper body function and can help alleviate symptoms associated with the keto flu, including headaches. Include electrolyte-rich foods in your diet, such as leafy greens, avocados, and nuts.
• Stay hydrated: Drink plenty of water, as the keto diet can lead to increased water loss. Aim for at least 8 to 10 cups of water per day, or more if you are particularly active or live in a warm climate. Proper hydration can help prevent dehydration-related headaches.

Carb withdrawal

• Allow a transition period: It takes time for the brain to adapt to using ketones as its primary fuel source. Allow at least three days for your body to transition from glucose to ketones.
• Consume MCTs and exogenous ketones: During the initial transition, use MCT oil and exogenous ketones to raise ketone levels and mitigate symptoms.
• Monitor your carb intake: Ensure you are consuming a sufficiently low-carb diet. If your carb intake is too low, you may experience a shortage of both glucose and ketones to fuel your brain.
• Eat electrolyte-rich foods: Consume meats, nuts, and leafy greens, which are good sources of potassium and magnesium.
• Increase salt intake: Use a liberal amount of salt on your food or add a pinch to your water. Aim for a daily intake of 4–6 grams of sodium.
• Drink electrolyte water: Add electrolytes, especially sodium, to your water and drink as much as you need.
• Stay hydrated: Drink plenty of water and consider drinking calorie-free, sparkling beverages to prevent dehydration.
• Avoid intense workouts: Intense exercise can increase stress on your body and may worsen headaches. It can also lead to excess sweating, which can worsen dehydration.
• Plan your meals: Eating enough fat can be challenging, as many people have been told to limit it. However, consuming at least 70% of your total daily calories from fat is crucial for effectively transitioning into ketosis and maintaining healthy blood sugar levels.
• Focus on fiber and fat: Eating fat and fiber together produces a high degree of satiety. Include foods made with flax seeds, which are high in both fiber and healthy omega-3 fatty acids.
• Eat frequent meals and snacks: On a low-carb diet, you shouldn't feel hungry for long periods. Plan your meals and include low-carb snacks to help offset cravings and reduce hunger during the transition.
• Manage stress: Stress can exacerbate symptoms, so find relaxing activities that bring you joy, such as taking a walk in nature or reading a book by the fire.
• Seek support: Reach out to people who have experience with low-carb diets, either online or in-person. They can offer support, answer questions, and share their own experiences.
• Be patient: Remember that any feelings of discomfort or frustration are usually temporary. The shift to metabolic flexibility is worth the effort and can lead to increased athletic performance and other benefits.

Frequently asked questions