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keto flu

Keto flu is a group of many symptoms that occur when your body undergoes keto transition.

It might sound like the usual flu you catch during winters and keep sneezing in a bed of crumpled tissues. But actually, it’s entirely a different thing.

You don’t sneeze or keep wiping your runny nose in the keto flu. Legend has it that the symptoms of keto flu are comparable to ceasing an addiction. Doesn’t seem like a regular cold now, does it?

The keto flu (also called carb flu) is a natural response when your body starts burning fat instead of glucose for energy. You feel sluggish and nauseous, you want to eat loads of carbs, and your dizzy mind is running wild. This usually happens when you remove all the carbs from your diet suddenly. You can even feel the carb addiction when you cut them out. If you still don’t understand how keto transition works, imagine yourself renovating your house and arranging your stuff all over again.  Placing different things in new positions can be confusing and tiring and yes, the feeling you’ll get is exactly how your body feels like; completely bummed and having no idea until you figure it out.

In the meantime, another cause of keto flu is the flushing out of electrolytes. During a keto diet, people usually are advised to drink loads of water and take mineral supplements. That’s because keto drains out all the electrolytes and water out of your body through excessive urination. When you don’t follow that advice, you get keto flu. Tada!

what causes keto flu?

1. Keto is a diuretic. You tend to go to the bathroom more to urinate, which attributes to a loss of both electrolytes and water in your body. You can usually help combat this by either drinking bouillon cube or Powerade Zero and by increasing your water intake. Mainly, you want to replenish your depleted electrolytes.

2. You’re transitioning. Your body is equipped to process a high intake of carbs and a lower intake of fat. Your body needs to create enzymes to be able to do this. In the transitional period, the brain may run low on energy which can lead to grogginess, nausea, and headaches. If you’re having a large problem with this, you can choose to reduce carb intake gradually.

symptoms of keto flu
  • Fatigue

  • Slight discomfort

  • Headache

  • Nausea

  • Cramps


The severity of these symptoms vary depending on several factors: how many carbohydrates your body is used to consuming, how quickly or mildly you transition to a ketogenic diet, age, and overall health.

These symptoms can last anywhere from a couple of days to a couple of weeks. As your body enters ketosis, it is important to maintain a proper source of energy, which can help prevent the keto flu.

how long does the keto flu last?

Well, it depends. For an average person that is starting a ketogenic diet, eating 20-30g of net carbs a day, the entire adaptation process will take about 4-5 days. For some people, ditching carbs in the first week of keto can be quite punishing. Although the length of the keto flu varies, the bad news is that it might take 3-5 weeks. However, don’t panic if you’re going to start your keto diet soon. The good news is that keto flu doesn’t affect everyone and even if it does, it’s temporary. And who doesn’t know of a few good tricks to battle the keto flu? So, let’s get right to the point!

preventing keto flu

To maintain this process of ketosis, you must be sure to include plenty of fats into your diet.

This provides the body with an alternative energy source, as it recovers from the “shock” it will endure as you cut carbohydrates from your diet.


Eating plenty of fats, macros and drinking an adequate amount of water will counteract the symptoms of the keto flu, leaving you with more energy, feeling less hungry and improve your ability to focus. Depleting carbs from your diet doesn’t mean you can’t burn fat for energy. Gather your fat supplies and get ready to boost your energy level.


Because  your body retains water differently when you eliminate carbs, it is important to drink plenty of water. You want to keep your electrolyte levels up during the transitioning phase, and throughout following a low carb diet. And since you’re prone to losing fluids, your body might have problem retaining minerals, electrolytes, and water. When you’ll be lacking these essential elements, you’re probably going to feel dull and down.

Increasing water intake and replacing electrolytes should relieve most all symptoms of Keto Flu.

Increasing your electrolytes will improve cognitive function, eliminate brain fog, reduce hunger and increase your energy.

Try using broth meat, and leafy veggies to drive out the dullness. Don’t forget to take your multi-mineral and multivitamin supplements to balance your electrolytes and minerals.

It is advisable to cut your carbs to fewer than 15g to ensure that you are well on your way into ketosis within one week.If you are experiencing any more keto flu symptoms, double check your electrolyte intake and adjust.

If you think that your activity has something to do with keto flu, then yes, it does. You can add some natural carbs to your meal to alleviate the symptoms. However, keto is better when all processed carbs are eliminated, only natural ones remain up to 5% in your diet, and only then you can enter ketosis.

To get rid of your laziness and nausea, gentle exercise and activity can help make your mood better and motivate you on your keto journey.

And yes, sleep becomes a headache than a soothing state when dealing with keto flu. Taking an Epsom salt bath and a nice cup of herbal green tea (valerian root and chamomile) can help you get that restful and relaxing sleep you’ve been craving for so long.

You may notice that if you’re an avid gym goer, you lost some strength and endurance. A temporary decrease in physical performance is typical. Once your body becomes keto-adapted, your body will be able to fully utilize fat as its primary source of energy.


It is also safe to drink coffee in order to counteract low energy levels during this time. Black coffee is the best option, however, coffee brewed with grass fed butter or served with heavy whipping cream are also carb free, keto friendly options. But remember: coffee is a diuretic, which will deplete the body of water and electrolytes. So again, remember to drink enough water to counteract what you may lose from coffee consumption.


When in doubt — drink water!

Even when think you’ve drank enough water — drink more!​