Keto Flu 101

The keto diet is has been growing in popularity for some time now, and its advocates praise the diet for encouraging weight loss, boosting energy, improving HbA1c levels for folks with type 2 diabetes, and more. Bee Healthy Clinics provides support for people undertaking the keto diet, and you can read more about burning fat the accountable way on our Keto Bee Program page.

It’s important to fully research any major lifestyle change, and the ketogenic diet is no different. As soon as you start researching the keto diet, you’ll quickly come across something referred to as “keto flu.” Sometimes, when starting a ketogenic diet, you may experience a collection of unpleasant side effects; the keto flu is a shorthand term used to describe the series of side effects you may experience when transitioning from a carbohydrate-filled diet to one that is significantly reduced in carbohydrates. These symptoms are often unpleasant but can also be mistaken for more serious conditions. It’s important to be aware of the signs of keto flu, what causes it, and what to expect. Here are a few keto flu basics to know:


The keto flu may be caused by several factors, but there is no known central cause. That’s because each person’s body responds differently to a significant reduction in carbohydrates. Since the body typically converts the glucose from carbohydrates into energy, reducing this energy source may cause adverse symptoms for some individuals until your body adapts to primarily burning fat for energy.

The level of unpleasant symptoms may be a result of the person’s diet as well. For instance, someone who eats carbohydrates made of refined sugars regularly may find it more of a challenge to switch to a ketogenic diet and experience harsher keto flu symptoms than those who primarily eat carbohydrates made from complex sugars. When your body goes into ketosis – the fat-to-energy conversion process – you may experience symptoms that are similar to withdrawal from substances, such as caffeine.


There are several indicators that can signal that you have the keto flu. Here are some common keto flu symptoms:

  • Constipation
  • Cravings for sugar
  • Diarrhea
  • Dizziness
  • Fatigue
  • Foggy brain or poor focus
  • Headache
  • Irritability
  • Issues sleeping
  • Mood swings
  • Muscle cramps
  • Muscle soreness
  • Nausea
  • Stomach pain
  • Vomiting
  • Weakness

Keep in mind that some keto flu symptoms are similar to more chronic or serious conditions, such as the actual flu or ketoacidosis. If you are experiencing serious symptoms, like prolonged diarrhea or excessive vomiting, seek medical attention right away.


Most people experience the keto flu for about a week. Remember, however, that not everyone experiences keto flu the same way. Some may find it more challenging to deal with the unpleasant symptoms of keto flu and could experience symptoms for several weeks.

The good news is that the keto flu symptoms subside over time once your body becomes acclimated its new primary source of energy. When the keto flu passes and your body adapts to ketosis, you can typically expect the symptoms to gradually subside. You may even feel more energetic.

Final Thoughts

While it’s important to understand the basics of the keto flu if you’re considering a keto diet, don’t forget that achieving your health and weight loss goals doesn’t have to be a solo journey. Bee Healthy Clinics is waiting to be your weight loss partner on your keto diet with resources and support – so take advantage of it and contact us today!

| Nutrition, Tips