What’s keto flu (and how to avoid it)

What’s keto flu

First of all, congratulations on arriving here to find out how to avoid the keto flu before it actually slaps you hard and makes you wish you had not made the decision to start your keto diet!

The keto flu is something that often comes as a big surprise to people when they are just beginning their keto diet journey. Fortunately you are about to find out all you need to know. As they say, knowledge is power – so I’ve gathered together all the information you’re going to want so that you don’t have to.

I’ll run you through exactly what the keto flu is, the symptoms and how to avoid it. If you already have the keto flu, I’ve included all the ways that you can help yourself to get over it in the shortest possible time.

The good news is that it’s not too much to worry about, and its certainly not reason enough to give up the amazing keto plan that you’ve decided to follow. Normally this will pass once your body is fully adapted to fat burning for fuel.

What is the keto flu?

Keto flu is a cluster of symptoms which can often hit when someone is using the keto diet for the first time.

The chances are your body has been burning glucose for energy, mainly because it had a plentiful supply, due to all those carbohydrates that you’ve been eating. The amount of sugar and grains now consumed in the standard western diet has skyrocketed in the last 20 years. So it’s no surprise that when you decide to take some action on your health and weight and reduce your daily carb consumption to 20g a day your body has a hard time adjusting.

For the first few days you will have a store of glycogen in your liver which your body can use for energy once all your glucose has been used. However, this store will only last so long, and then another source of energy needs to be found.

You can expect this process of using up all available glucose and switching to another source for energy to take about three days. Once glucose is no longer available, your body will switch to its second metabolic pathway: using fat for fuel. This is the process by which you will produce ketones and it’s obviously what you’re aiming for.

This is a completely natural process, and in past times when food was not continuously available, it is the process by which we stayed alive until we could eat again. Without being able to use stored fat for energy, we would have had no way of surviving for more than a few days after our last meal.

However, few of us have had a need to switch to fat burning before coming to the keto diet and if this is the first time that you have been on this diet, your body may not be all that efficient yet at burning fat for fuel. There does seem to be some evidence that certain people have a genetic advantage and can do this more easily than others. For the rest of us it’s a case of practice makes perfect, and we get better at fat burning the more times we eat low carb and make our body switch from glucose to fat for energy.

The more times you go low carb with your diet, the greater your metabolic flexibility is going to be.

When you first begin to burn fat for fuel, your cells release a lot of extra water which is why you’ll notice that you’re going to the bathroom much more often than normal. Unfortunately some of your micro nutrients and especially electrolytes are going to get flushed out too.

The three most important electrolytes are Sodium, Potassium and Magnesium and these are responsible for many of the symptoms which make up the suffering called Keto “flu” so you’ll be interested in knowing which one causes which symptom as you’ll be better placed to do something about it.

The symptoms of keto flu

As we have discussed, when you first begin the keto diet you will be flushing out some important electrolytes and nutrients. The lack of these will produce different symptoms.

Sodium is one of the first electrolytes that will let you know its in short supply, followed by Magnesium and Potassium. Here is what you’ll be feeling if you are running low:

Lack of Sodium

  • Fatigue
  • Headache
  • Nausea
  • Confusion

Lack of Potassium

  • Muscle weakness with or without cramps
  • Nausea
  • Heart Palpitations
  • Low blood pressure
  • Feeling low and/or confused

Lack of Magnesium

Magnesium is important in more than 300 systems and reactions in the body. The importance of Magnesium cannot be overstated, and unfortunately many adults are low in Magnesium even if not starting a keto diet.

Magnesium is vital for protein synthesis, muscle and nerve function and blood pressure control to mention just a few. It also helps your body to absorb calcium and Potassium.

some symptoms of a lack of Magnesium include

  • Loss of Appitite
  • Fatigue
  • Nausea with or without vomiting
  • Muscle tingling or numbness
  • Abnormal heart Rhythm

Other causes:

In addition to a lack of micro nutrients, it is not uncommon to go through a process of withdrawal from sugar. Sugar is highly addictive due to its ability to produce Dopamine in the brain, and suddenly withdrawing won’t harm you, but it can be uncomfortable. There isn’t much you can do about this, except to remind yourself of all the weight loss/ health benefits you’re going to be enjoying once this stage is over with.

Altogether this is quite some list, and it’s no wonder that when the keto flu hits, it hits hard. The great news is that its both temporary, lasting on average one to six days, and there are things you can do to cure it or avoid it.

How to cure the Keto Flu ( or avoid it if you’re reading this soon enough)

It’s possible that up to 70% of people can avoid the keto flu if they take the right steps beforehand. However, the remaining 30% and anybody who was not well-prepared will need to take all or some following steps:

The first thing you want to do is to ensure that you’re drinking enough. You will be loosing extra fluids, so make sure that you’re not becoming dehydrated, which will make you feel ill. Use water, broth, coffee –  which ever you feel like. Just make sure you’re not thirsty.

Also make sure you’re eating enough fats. Your body is not yet efficient at burning fat for fuel and you need to give it all the help you can. Eating enough fat will help with the symptoms of keto flu too. Fill up on any healthy fat that you enjoy by making sure you’re eating fatty cuts of meat or fish as well as using healthy oils such as olive oil or coconut oil. Don’t worry, this may feel strange at first but fat is your new best friend .

To deal with the sodium loss use salt on your food, and a bit more than normal would help too. In my opinion Pink Himalayan Salt is best. You could even dissolve a few crystals on your tongue.

Keto foods such as Bone Broth can be great for your salt intake as well as being very nutritious generally. Bacon is a good salty low carb choice too.

For low Potassium, foods such as Avocado, Salmon, Kale, Brussels Sprouts, Broccoli, Turkey and Beef are all low carb and packed with Potassium.

Foods high in Magnesium include Avocado, Almonds, Brazil Nuts, Pumpkin seeds, Chia seeds, Salmon, and leafy greens. All great sources of Magnesium  as well as being keto friendly.

Sleep is important

It’s also important to make sure you’re getting enough sleep.

A lack of sleep can cause elevated levels of cortisol as your body will be under stress. High cortisol will make you feel irritable and on edge.

Make sure you do what you need to do to stay relaxed, and cut back on any hard exercise. It’s good to keep busy, and some exercise can be helpful in getting you into ketosis more quickly. However, the gym can always wait a few days until your keto flu has passed.


If you follow these suggestions you should be able to manage all or most of your keto flu symptoms. If you’re one of the lucky ones, you may even be able to prevent this happening to you all together.

One of the most important things to do is to eat a nutrient dense diet that includes vegetables as well as meat or fish. This will minimize the keto flu and is good advice for the whole of your keto diet.

Keep your goals in mind and remind yourself that keto flu is only a temporary condition, and you will normally feel much better in a few days.

If you’re still worried about getting the right micro nutrients to prevent keto flu this electrolyte mix will give you all the trace minerals and electrolytes you need. This will make avoiding the flu easier for you with everything in one place.

Electrolyte Mix Supplement Powder, 90 Servings, 72 Trace Minerals, Potassium, Sodium, Electrolyte Replacement Keto Drink | Blueberry-Pomegranate Flavor | Dr. Price’s Vitamins, No Sugar, Vegan Non-GMO

  • THE HIGHEST QUALITY ELECTROLYTE HYDRATION FORMULA. has a blend of over 72 Trace Minerals and Electrolytes created to benefit individuals ranging from the elite athlete to your personal hydration needs.
  • NON-GMO, GLUTEN FREE, VEGAN, KETO & NO SUGAR! 100% Naturally Sweetened with Stevia Leaf Extract.
  • Powdered water-soluble sports drink formula that mixes with liquid for FAST and EASY absorption.
  • Balances and Restores HEALTHY Electrolyte Levels for Super Hydration. Minerals, including magnesium, sodium, and potassium. Trace elements of zinc and 72 other trace minerals.

This time next week you could be feeling on top of the world and really enjoying all the benefits that the keto diet is going to be bringing you.




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