The dreaded keto flu. Also known as induction flu. You start your keto diet, full of energy and enthusiasm, then as you get to the end of the first or second week, feelings of fatigue and lethargy start to set in. Doubt about the diet creeps into your mind and you feel the temptation of breaking your promise to yourself about sticking to the diet. But stay strong, it doesn’t have to be this way!


Firstly, before we delve into what keto flu is, let’s take a look at why we go through it in the first place. This infographic outlines the initial short term effects, and the long term effects that we want to get to.

Serious about wanting to start keto?

If your really serious about getting the most from keto, avoiding the initial side effects and getting to the long term positive effects as quick as possible, check out the keto camp course here, put together by top podcaster and trainer, Chris Albert.

What is keto flu?

Keto flu is your body in transition. For most of us, all our lives we are burning glucose. Glucose gets burned up fast by your body, which leaves us wanting more glucose, more often. On the keto diet we are drastically cutting down the glucose available to our body. This forces the body to transition into “fat burning mode” or ketosis. This allows for the break down of fat in our body and the  transition into using fat as fuel instead of glucose. This is no mean feat for the body, and in this transition phase, we can feel a little under the weather.


Keto flu symptoms


The length of time keto flu lasts varies widely from person to person, with some not experiencing it at all. Those with good metabolic flexibility, which is the ability to switch back and forth between fuel sources may find that they get no symptoms. Unfortunately the modern diet has a lot of carbs and sugar in it, so many of us don’t get to develop this metabolic flexibility and may struggle in the initial stages of the diet, this could last anywhere from one week, to six.


Lethergy, brain fog, irritabiliy, tiredness

 These 4 are a bit harder to deal with, but look at he experience as an exercise in mental fortitude, a challenge. It won’t last forever and you will come out the other side a stronger, healthier person. Many keto dieters are avid coffee drinkers. A bit of caffeine is great for a boost, but try not to over do it. Exogenous ketones help hugely too, more about these further down.

Keto flu diarrhea

Diarrhea is no fun at the best of times, but coupled with any of the above, and your really in for a sh*t time, literally. Keto flu diarrhea is often times brought by the sudden change in diet. Fats are harder to break down than carbs and protein, therefore by switching to a diet that is mostly fat, we are giving our body a lot of extra work to do. This can put a strain on the digestive system, and we may experience keto flu diarrhea. If you experience keto flu diarrhea, it may help you to add more fiber to your diet.

Keto headache

The dreaded keto headache comes on due mainly, a slight mineral deficiency/imbalance. The keto diet acts as a diuretic. This basically means we pee more than we would do normally and lose fluids faster. In our pee we also lose minerals. To re-balance he minerals that we lose, we can either supplement, or increase our salt intake and try to eat mineral rich foods such as avocados, nuts, and leafy greens. I find a combination of both works best for me. It’s always handy to have some low carb electrlytes on hand in case you start feeling dehydrated.

When choosing a low carb keto electrolyte, make sure it is just that. In other words, check the ingredients and nutritional values. You don’t want anything conaining sugar for a start. Check the label for the amount of carbs too. Keto vitals make a great product specially tailored for the keto dieter.

Exogenous ketones

What are exogenous ketones and how do they fit in to the keto adaptation phase of the keto diet?

Well as mentioned, the adapation phase is a period in which your body is switching from using glucose as fuel, to using ketones, which takes time for your body to learn how to do efficiently.

Exogenous ketones, are ketones that are ready to go. When you supplement with them, they naturally put you straight into a state of ketosis. Kind of like a guilt free short cut really!

because exogenous ketones naturally elevate your blood ketone levels, you can avoid the transition period in which your body has little glucose, but can’t produce enough ketones yet.

Perfect keto do an awesome range of exogenous ketones and have great flavours such as coffee, peaches and cream, chocolate sea salt and vanilla.

Keto Fiber

When following the keto diet, we must make sure we are eating plenty of veggies. Vegetables not only provide us with vitamins and minerals, but fiber too.


There are two types of fiber, they are –


  1. Soluble fibre
  2. Insoluble fibre


You are likely to be getting a certain amount of these if you are eating plenty of veggies, nuts and seeds anyway on the keto diet.


*Soluble fibre is simply fibre that dissolves into water and is fermented into gases by beneficial bacteria.


*Insoluble fiber is does not dissolve in water and provides bulk to your stool, and is fermented in the large intestine. Both are prebiotic, which means they are good for our gut bacteria, unless the individual has underlying health issues such as SIBO.


Many foods contain a mixture of both fibers. Here is an example of insoluble and soluble fiber ratios in some keto friendly foods –

  • Kale, 45% insoluble fiber, 65% soluble fiber 45% 45%
  • Almonds, 90% insoluble fibre, 10% soluble fiber 90% 90%
  • Olives, 50% insoluble fiber, 50% soluble fiber 50% 50%
Fiber has some of the following benefits –


Bulks out our poop (helping prevent watery stool)

Keeps us regular (helping prevent constipation)

Prebiotic (feeds the good bacteria in our gut)


Many people fall into the trap of not getting enough fiber on the keto diet. Even if are eating plenty of veggies, we are probably missing resistant starch. This type of insoluble fiber resists digestion and is broken down by good bacteria in our gut.


Resistant starch can be found in the following foods –

So, you see, you won’t be getting much of these on the keto diet. At first glance, we see potatoes and rice and think, way too many carbs for the keto diet. Whilst this is true, they aren’t actually as bad as they first appear. The act of cooking then cooling such foods as potatoes actually changes the carb filled fiber in the potatoes into resistant starch. This means a lot of the carbs resist digestion and are instead metabolized into other beneficial by-products by our gut bacteria further down the digestive tract.


For a really in depth look at resistant starch, Mark Sisson’s blog titled the definitive guide to resistant starch is an awesome resource.


Now I’m not saying go and pig out on a bowl of chilled potato salad, that would still push you out of ketosis. But, what we can do is supplement with potato starch powder, such as Bob’s red mill unmodified potato starch.


I prefer to get nutrients from whole unprocessed foods, but it’s hard to get resistant starch into your diet on keto without pushing you out of ketosis. So this powdered potato starch is a worthwhile compromise. Bob’s, the brand is a trustworthy family business and their potato starch is minimally processed. The potatoes are crushed, the starch is collected and then dried into a white powder. Supplementing with potato starch this way means you can get the benefits of the prebiotic, resistant starch whilst avoiding the insulin spike that you’d get from eating the whole potato.


Now, make sure you do take it easy to begin with. Depending on the health of your gut, and differences between individuals, potato starch could give you a bit of gas. This is dependent on your gut bacteria and how well they break the potato starch down.


Recommended dose to start – half a teaspoon mixed into cool water.

Final thoughts, the keto flu stack

So, finally, what is the best “stack” for your keto diet induction phase? 




1. Exogeonous ketones

Elevate your blood ketone levels naturally and avoid the dreaded adaptaion phase in which your body has no glucose and isn’t producing ketones yet

2. Keto course

Give yourself as much knowledge as possible going into the keto diet so that you have the best chance of success.

3.Keto Fiber

Try add some resistant starch into your diet, just try a little to begin with!

4. Low carb electrolytes

Maintain your mineral levels to keep your energy and brain function up and avoid dehydration!


You have successfully subscribed, please check your email and add us as contact so you don't miss out!