keto flue

A common thing people keep asking me, is that after a few days into a ketogenic diet is, why do I feel so tired, and have a horrible headache, maybe this diet is not working for  many people in the community know this induction period as the keto flu.

You see, as we switch our metabolism, from burning primarily glucose for fuel to burning fats, that transition takes time, and for many of us, we have not had to switch to a fat burning metabolism since we were children.

One of the common symptoms of keto flu is headaches, personally, I like to think of the headaches as sugar withdraw, it is similar to me as coming off caffeine, it truly resembles a drug like addiction withdraw, there are studies now that say sugar can be as addictive as a drug (

Common Symptoms

While personally I only had the headaches, here are the common keto flu symptoms, that people talk about:

  • Craving Sugar, bread, pasta, potato rice, chocolate
  • Headaches
  • Dizziness
  • Brain fog
  • Sleepiness
  • Fatigue

One of the primary reasons for these symptoms, is that a higher carbohydrate diet, holds onto salt with water in the body, and if you are like me and just dived in keto head first and went cold turkey, like many of us do, during the first few days you will find that your kidneys will dump water with salt quickly through your urine (this will show a huge initial weight loss and is water weight) if that dump of salt and water is not managed correctly, it causes a slight electrolyte imbalance, and can cause many of the symptoms listed above.

How Long does it last?

It really depends on the person, their previous diet, health and age all come into the equation.

Most find that day 3-4 is the worst and feel normal by day 5-7, while others may take a few weeks to fully adapt to their new dietary change.

But there are 2 main things, you should be focusing on, to ensure smooth transition and ongoing maintenance.

How long will the keto flu last?

It depends. Some people don’t experience any symptoms at all, but some suffer anywhere from a day to a week. Rare cases up to two weeks. Everybody’s bodies are different and some people handle switching over better than others. You might consider starting keto on a weekend or sometime when you are able to get good rest deal with the symptoms.

For those of you that are going through the keto flu, don’t give up! I know you feel like it’s never going to get better but stick with it and you´ll be so happy you did!

Tips to Deal with Keto Flu?

So what can be done to lessen the symptoms?

First you understand why your body is reacting this way. Your body’s been burning glucose for energy so it’s basically full of enzymes that are waiting to deal with the carbs you eat (and probably store them as fat). But now the body needs to make new enzymes that burn fat for fuel instead of carbs, and the transition period causes your flu-like symptoms. There are some things you can do to lessen the symptoms of the keto flu and to make it go away sooner (to force the body to transition sooner) Ok, let’s get to the good part “ what to do:

  • you’re probably dehydrated. Drink PLENTY of water while you’re on the keto diet. And then some more.
  • Watch your electrolytes. When the body is getting rid of excess insulin from your former carb-crazy diet you´ll lose lots of fluids that have been retained in your body. This causes the rapid weight loss most people see in their first few days of ketosis, it’s mostly water, sorry. When you lose all the retained water you also lose electrolytes like sodium, magnesium and potassium. When you’re lacking them you’ll feel like crap so when you’re feeling ill on the keto flu try things like chicken/beef broth and look for foods rich in these minerals. Take a multi-vitamin and a multi-mineral
  • Don’t eat too much protein. The body can transform protein into glucose so if you eat too much of it in the first days it will slow down the transition.


The most common Electrolytes we get from our foods are sodium, potassium, calcium, chloride and magnesium.

As stated before there is an initial loss of the electrolyte sodium and pending on the person they may feel dizzy and b2, you have 3 simple options:

  1. Get someone to go to the local drug store and buy a sugar free electrolyte powder.
  2. Get someone to go to the grocery store and by a sugar free electrolyte drink.
  3. For a natural option add  ½ a teaspoon of salt to a large glass of water, with a squeeze of lemon and a dash of stevia.
  1. Try to ensure your ketogenic diet contains the following minerals/vegetables regularly, to ensure mineral balance and micro nutrients (Sea Salt, Avocado, Spinach, Mushrooms, cabbage, broccoli, almonds, Red Meat)
  2. If you are eating enough real food, from what I mentioned above potassium and sodium will look after itself, you should not have to substitute more unless a blood panel says your deficient.



Many people tell me about getting painful cramps in their legs when eating a keto diet, this is usually related to low magnesium.

The magnesium from green vegetables in a ketogenic diet should be enough, but sadly in the last 20 years magnesium in farmed foods is 30% lower and a study ( sponsored by the National Institutes of Health shows that 68% of Americans are magnesium deficient, so you can see the risk of exacerbating an already low mineral state when transitioning your diet.

B Vitamins

B vitamins are very, very important for transiting to keto, many people coming from a western diet will find they will be low in a few of the essential B vitamins, especially B1 (thiamine).

The following B vitamins are used for Ketosis (B1, B2, B3, B5 (Pantothenic Acid), B6)

Option 1: B Vitamins from Food

One of the natural foods that contains all these vitamins is Nutritional Yeast,

Option 2: The Supplement Approach from the chemist.



If your following a ketogenic diet or just started, it is important to ensure you keep your electrolytes in balance, you do this primarily by foods and some supplements, this can make up the shortfall of bio available essential nutrients due to low levels in the food supply and our previous dietary habits.

If you do this correctly and ensure your diet is not highly processed before you go cold turkey, you will most likely avoid keto flu, but if not, I hope these simple tips will help you on your ketogenic diet journey.