Keto Flu: What it Is and What to Do About Low Carb Flu

Give me some love!

AGHHH! I am suffering the dreaded KETO FLU. I have been low carb for several months and practicing keto for almost a month. So far, I’ve had zero negative side effects and thought I was safe. WRONG. It hit me hard this weekend. Always the opportunist, I decided to write a series of posts chronicling my experience with keto flu.

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keto flu
keto flu

What is Keto Flu?

If you do any amount of reading  on a ketogenic diet, you will come across the term keto Flu. However, you can’t truly understand it until it happens to you. To put it in simple terms, it is what happens to your body when you switch over from fueling your body with glucose to fueling your body with fats. Think of it as carbohydrate withdrawal. You have run on sugar for so long that your body isn’t sure what the heck you are doing to it.

Dramatically changing the fuel you give your body shocks your metabolism. Many people suffer some negative side effects while in this adaptation phase. Among the most common side effects are: nausea, headaches, fatigue, mental fog, and upset stomach. Everyone tells me that once you’re out on the other side the benefits outweigh the drawbacks. Unfortunately right now, in the thick of keto flu, I am questioning that logic.

What Causes It?

While there are various causes, it seems one of the most common is electrolyte imbalance. When you’re coming off carbs, your body flushes out a lot of excess water that has been stored with the carbohydrates. Unfortunately, that also flushes out the various vitamins and minerals stored in your body. This is why it’s important to drink lots of water and make sure you’re getting enough sodium, magnesium, and potassium.

Another cause is jumping in too quickly. If you’ve been eating a mostly low fat diet for a long time, and then shock your body with lots of fat, it seems only logical that some nausea and upset stomach will follow. Your body isn’t yet sure what to do with all that extra fat. Another cause could be the change in your gut bacteria. Changing your diet will kill off the inflammatory bacteria that were living in your gut and this shift can cause discomfort. Whatever the cause, it is certainly unpleasant.

My Experience

I’m not sure why I am getting keto flu now, after several months on low carb but I have a few suspicions. I have been trying to ease myself into low carb. First, I started with about 100 grams net carbs, decreased to 70, then 50, and now I eat roughly 20-30 grams daily. With my beach trip coming up soon I decided to double down my effort. For the past week, I ate almost zero carbs. My typical day was bacon, eggs, and steak, which seemed great, at first. Unfortunately, the high did not last!

Saturday evening, after eating a dinner of steak, mashed cauliflower and bacon wrapped jalapeno poppers, I started feeling a little queasy. Thinking it was just indigestion, I took my Apple Cider Vinegar and went to bed early. Sunday morning I woke up feeling worse. My nausea was through the roof, and I also had a headache, and extreme fatigue. BUH.

I thought it was just a food hangover from my huge meal Saturday night but it did not improve as the day went on. The sight of food made me ill and I didn’t even want my daily coffee, which is my solace. I knew something was wrong when we went to TWO parties yesterday, with gorgeous spreads of food and I wanted NOTHING to eat. If only I had listened to my body and not eaten! It would have been a perfect day to practice fasting.

What Not To Do

At this point, I have begun to identify what I’m feeling. So, because I occasionally have really bad judgement, I thought to myself, “If this is keto flu, maybe a little bit of sugar will improve how I feel.” So, at the first party, I ate a little bit of cake and at the second I had a little bit of macaroni and cheese and a little more cake. BAD IDEA.

OMG WHAT IS WRONG WITH ME?! Now, I feel like garbage squared. The sugar made it worse. SO. MUCH. WORSE. And… that’s where I am today. I went to bed very early last night, hoping I’d wake up feeling better today. Wrong again. I am now 36 hours into the keto flu hell and I don’t wish this on my worst enemy. Today, I am taking a different approach.

What To Do

It turns out that eating sugar only stalls the process and lengthens the amount of time you will suffer! So, don’t do what I did! Put that cake down. Instead, I did some research on what I should do going forward.


  1. Electrolytes – Make sure you’re getting potassium (found in spinach, avocado, and salmon), Magnesium (also found in spinach, and avocado or dark chocolate) additionally, I like Dr. Teals Epsom salt soaks. Be careful when taking supplements, because we absorb magnesium through our skin better than we can digest it in a pill. Finally, add sodium, which is easy. Just remember to salt your food.
  2. . Drink Up  -Drinking enough water is so, so important. Don’t let yourself become dehydrated. You’re flushing lots of stored water.
  3. Bone Broth – Bone broth is a great source of sodium and also helps with nausea.
  4. More Fat – I choked down my bulletproof coffee this morning and while I didn’t want it, I did start to feel a little better after.
  5. Less Protein – Did you know that our bodies can convert excess proteins into glucose? Yeah, me either.
  6. Exercise – I doubt you feel like it, but going out for a mild to moderate walk did help me feel a little better.

This Too Shall Pass

While I am currently questioning everything I thought I knew about living a ketogenic lifestyle, I know this too shall pass. In most folks, the keto flu only lasts for a few days. Once you get past it, I am told you can expect to feel increased energy, mental acuity, loss of cravings, and myriad other benefits. I will be sure to let you all know how I progress through the remainer of my keto flu.


Until tomorrow, thanks for reading. I hope you have a beautiful and blessed day!




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