How to Avoid the “Keto Flu”

Science by Temple Stewart, RD

The ketogenic diet is not only popular in the United States, but globally as well. More and more people are giving keto a chance, and experiencing great results. According to a recent survey, out of the more than 300 surveyed, 94% of people experienced “positive” or “very positive” changes in their health. Even with the positive experiences, some may be nervous about starting the ketogenic diet because they’ve heard about the “keto flu”. Let’s break down what the keto flu is, and most importantly how to avoid it. 

What is it? 

Put simplistically, the keto flu is a collection of symptoms experienced by someone who is starting the ketogenic diet. Many people feel these symptoms due to electrolyte loss. As insulin decreases on keto, sodium is excreted through the kidneys [1]. It’s also much easier to experience dehydration on keto as you’re not eating as many dietary carbohydrates. Glycogen (the stored form of carbs) binds to water in the body, so naturally, you lose this water as you eat lower carbs. Some of the symptoms of the keto flu may include headaches, irritability, weakness, muscle cramps, dizziness, poor concentration, difficulty sleeping, and sugar cravings. 

How do I avoid it? 

    • Stay Hydrated: Carry a water bottle with you and make sure you stay well hydrated. Sip on water throughout the day, especially if you live in a hot climate. Start with sticking to the general guidelines of 6-8 cups of water per day, although you may need more during the first week [2]. 
    • Electrolytes: Replacing electrolytes is key in making sure you avoid the keto flu. There are plenty of electrolytes replacements on the market, just make sure to buy one that also contains sodium. You can also get sodium by salting your foods. Also, include foods higher in magnesium and potassium like leafy greens and avocados [3].



    • Prioritize Sleep: Making sure you practice good sleep hygiene is crucial. Plenty of rest will make your transition into ketosis seamless. Avoiding electronics, limiting caffeine, and keeping a normal sleep schedule can all be helpful to promote a restful night’s sleep [4].
    • Avoid Strenuous Exercise (at first): It’s most common to experience problems within the first week, so as long as you take it easy during that time, you likely won’t have any issues. As your body adapts to the new fuel source, exercise becomes easier and easier. Plan to resume any strenuous exercise soon.
    • Eat Enough Protein and Fat: These two nutrients will keep you full and satisfied, therefore decreasing the chance you give into sugar cravings. Studies also show that eating low-carb diets can be very helpful to avoid sugar cravings [5].

Do these things to avoid the ketogenic flu and you’ll feel great as you transition your diet. Overall, most people don’t feel these symptoms if they’re well prepared with electrolytes and plan when they start keto!



  1. Horita, S., Seki, G., Yamada, H., Suzuki, M., Koike, K., & Fujita, T. (2011). Insulin resistance, obesity, hypertension, and renal sodium transport. International journal of hypertension, 2011, 391762.
  2. Munos, M. K., Walker, C. L., & Black, R. E. (2010). The effect of oral rehydration solution and recommended home fluids on diarrhea mortality. International journal of epidemiology, 39 Suppl 1(Suppl 1), i75–i87.
  3. Gröber, U., Schmidt, J., & Kisters, K. (2015). Magnesium in Prevention and Therapy. Nutrients, 7(9), 8199–8226.
  4. Chaput, J. P., & Tremblay, A. (2012). Adequate sleep to improve the treatment of obesity. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 184(18), 1975–1976.
  5. Martin, C. K., Rosenbaum, D., Han, H., Geiselman, P. J., Wyatt, H. R., Hill, J. O., Brill, C., Bailer, B., Miller, B. V., 3rd, Stein, R., Klein, S., & Foster, G. D. (2011). Change in food cravings, food preferences, and appetite during a low-carbohydrate and low-fat diet. Obesity (Silver Spring, Md.), 19(10), 1963–1970.

This article is for informational and educational purposes only. It is not, nor is it intended to be substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.