Although the keto diet is easy once your body has adjusted, you can definitely feel off-colour at times during the first few days, the keto flu. This is because your body, which has been used to powering itself by burning sugar, is transitioning to a new fuel – fat. It knows exactly how to do this but it does take it a little while to adapt. This is even more true of your mind. 

While the adaption is taking place, you may suffer from various flu-like symptoms such as headaches, tiredness, dizziness or irritability. You are withdrawing from a powerful drug, which you have been using for your entire life, so it’s not surprising that your body and mind protest a bit at first. Some people give up at this stage.

The keto flu is your body’s way of telling you it is in the process of starting to burn fat instead of sugar (this is ketosis) but it takes a bit of time for your body to adapt and this is why you may experience some of the symptoms listed below.


  •   Lethargy
  •   Headaches
  •   Crankiness
  •   Muscle cramping
  •   Nausea
  •   Lack of motivation
  •   Lack of focus
  •   Sugar cravings
  •   Lightheadedness

Thankfully, unlike standard flu, it’s not contagious and passes quickly. However, if you are one of the people that experiences it (not everyone does), then there are some simple steps that you can take to overcome any symptoms.

What to do

Salt and Water: Ask anyone in the nutrition field and the first thing they will tell you to do is to increase your salt and water intake, because this is what is most commonly responsible for any symptoms. If you do experience any of the above, drink a glass of water with a half a teaspoon of salt stirred in. This is a proven technique and has been known to eliminate symptoms in less than an hour.

You should also ensure you are drinking enough water daily too. Remember, the heavier you are, the more water you are likely to lose in the early stages of keto. So, make sure you keep your glass of water close to hand.     

Eat more fat: This may seem like an obvious tip for someone doing keto but it really does work. When you reduce your carbohydrate intake dramatically, your body can panic and start to think it’s starving as a result of not enough energy (food) being  consumed. This is where fat comes in. Replace those carb calories with delicious tasting fat and your body will thank you for it.

Take it easy: We are huge advocates of physical activity here at Nic’s Keto Diet, but if you are still feeling symptomatic after trying some of the tips above, cut back on the amount of physical activity you undertake until it passes.

Trust the process: Do not panic, keto flu is perfectly natural and many people experience it. The key is to remember that you are not alone. Follow the steps above and stick to your diet and it will pass. Once you are in ketosis the symptoms will be a thing of the past.