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Why I Get the Keto Flu?



In this article, I will explain what many people refer to as the “keto flu”. It is not an actual sickness nor is it contagious, but it is still bothersome nevertheless. The keto flu is a bundle of symptoms that usually occurs after the first few days of a Ketogenic diet. Keto flu symptoms include

  • Fatigue
  • Headaches
  • Sugar cravings
  • Irritability
  • Insomnia
  • Muscle cramps
  • Muscle Weakness

Why You Get the Keto Flu

This happens because by this point you have gone a few days without large quantities of carbohydrates. Your body has a very limited amount of glycogen stores (stored carbohydrates) in its liver and muscles. In fact, the average person has between one and two pounds of stored carbohydrates at any given point. As you deplete this stored glucose via exercise or carbohydrate restriction, that it when your body is essentially without fuel. It’s panicking because it can’t make glucose from the carbohydrates you aren’t eating. So instead it does something called gluconeogenesis, the process of converting protein to glucose. So even though you may not be eating any carbohydrates, your body is so desperate for glucose it uses energy to get it from protein. That’s why consuming enormous amounts of protein won’t do you any good in achieving ketosis. Instead of eating lean beef and chicken all day, consider eating as much fat as you can. Or instead, try an intermittent fast if you’re able to.

Another cause of the keto flu is a lack of electrolytes. This is because your body is experiencing difficulty in water retention due to the extreme lack of carbohydrates. Glucose molecules contain water, so naturally the more glucose present in the body, the more water retention there is. As carbohydrate intake is cut, excess water weight is flushed out of the body. That’s why people may initially lose ten pounds in their first week of a Ketogenic diet. Unfortunately, electrolytes such as sodium and potassium are flushed out of the body as well. This is why you may experience muscle cramps during the keto flu. Although there haven’t been any scientific experiments attempting to resolve the keto flu, common remedies include significant electrolyte supplementation.

The Worst Part

In my opinion, the hardest part about the keto flu is the sugar cravings. Perhaps it’s easier for women because they are used to dealing with menstrual cravings. However, for me, these are the most intense cravings I’ve ever had. And it really puts things into perspective. I would have never thought that I’d ever crave peanut butter and jelly as a grown adult, but that’s what ends up happening for the first week of a ketogenic diet. The keto flu is a short term pain that will ultimately lead to a long term gain. I’ve had many people tell me that they’ve tried a Ketogenic diet and experienced nothing but brain fog, weakness, insomnia, cramps, etc. Except they would never make it past the keto flu before they would renounce the diet altogether. Your high blood sugar, excess body fat, and cognitive shortcomings are not going to get solved within one week.

If you are truly committed to achieving a healthier life for yourself, then you will understand all of the hype surrounding a ketogenic diet once you reach ketosis. Except I faced a glaring problem when I first started a Ketogenic diet. My issue was that I had the keto flu for three weeks straight. And I’m going to share with you why so you don’t make the same mistake I made. Like I mentioned earlier, I always crave PB & J during my keto induction phase. So I would replicate it using a 6 net carb tortilla wrap and 4 net carb almond butter (I obviously didn’t use jelly). This is only 10 net carbs, which shouldn’t throw you out of ketosis nor prevent you from achieving it. Except I overlooked something very important regarding the tortilla wrap. There were more ingredients in that tortilla wrap than years I’d been alive. And I promise every single one of those scientifically formulated chemicals and preservatives will do everything it takes to give you more cravings and halt your progress. Please check the nutrition label and try your best to eat foods with as little ingredients as possible. The same rules should apply for those “keto snacks” found in your local nutrition store. These are products made intended to make large amounts of profit by people who probably would never consider eating them themselves. Through my testing of such products, I haven’t found a single “keto snack” that doesn’t give me cravings or an upset stomach. That’s not to say all of the Ketogenic supplements you see on the shelves are bad for you. I personally have found that everything BulletProof is tremendous.


The keto flu is a natural process of the Ketogenic diet. As long as you fight through the cravings and get your electrolytes, you should start to see improvements with each day. I’m lucky since I’m young, it only takes me about 7 days before I know I’m in full ketosis. And I understand that for many older adults, many who have never run on anything but glucose, it may take up to three weeks to enter ketosis. Remember why you’re doing this diet in the first place.



This content reflects the personal opinions of the author. It is accurate and true to the best of the author’s knowledge and should not be substituted for impartial fact or advice in legal, political, or personal matters.

© 2021 Cody Piunno


DW Davis from Eastern NC on February 01, 2021:

My friends who have tried the ketogenic diet never mentioned this aspect. I have not tried to go carb-free, and probably will not, but I found this Hub interesting and informative.

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