Intermittent Fasting on Keto – A Match Made in Heaven

Siim Land

Intermittent Fasting on Keto is a match made in heaven. Both of them have gained a lot of public attention over the past few years and have easily become the most popular diets in weight loss and holistic health.

What’s the Buzz?

Is there actually any real benefit to intermittent fasting and the ketogenic diet or are the two simply fads? Of course, in the fitness community, a lot of the hype is created by marketing and die-hard fans, especially in the field of nutrition, but it doesn’t take away from the sheer effectiveness of IF and keto.

Intermittent Fasting and Keto are like a match made in heaven – they are both extremely enjoyable and help the individual achieve their body composition goals, whatever that may be.

The thing is that physiologically, they are almost identical – like the two sides of the same coin. Intermittent fasting (IF) leads to a state of nutritional ketosis, which can be achieved by eating a low carb ketogenic diet as well.

Fasting and Ketosis

To understand the physiology of it, we need to go through a hypothetical scenario wherein we want to establish a state of fasting ketosis.

If you start abstaining from food, your body will soon run out of its inner stored calories, namely liver glycogen (100-150 grams). This happens already after an overnight’s fast and within 16-20 hours, your stores will be completely empty. What happens afterwards is quite magical and amazing.

Captain Liver then flies to the rescue and starts to produce more ketone bodies that begin to circulate the bloodstream to sustain the body’s energetic needs.

Ketone bodies are fatty acid molecules that can be either converted from your own body fat or derived from the fat calories found in food. At first, the brain and muscles can’t effectively utilize ketones because of the metabolism being still geared towards burning sugar, given that the glycogen stores were just recently full i.e. you’ve been eating too many carbs.

What Happens Next

After about 2-3 days of fasting, ketone production will increase exponentially and the body enters a state of nutritional ketosis. Fasting induces ketosis very rapidly and puts the body into its more efficient metabolic state. Ketone bodies may rise up to 70-fold during prolonged fasting[i]. This is the point in which your liver will be spewing out ketone bodies like a factory plant and you’ll be in very deep ketosis.

Intermittent Fasting and Keto
Intermittent Fasting and Keto

Fat burning will increase exponentially and you’ll be deriving energy solely from your adipose tissue. This actually preserves muscles from being catabolized as well because fasting increases Human Growth Hormone (HGH). In fact, it does so by an astonishing 1300-2000%[ii]. Ketosis itself is also an anti-catabolic state, so you won’t really suffer any loss in lean body mass whatsoever, which doesn’t mean you can’t lose muscle while fasting. Only after extremely extended fasts, such as 10+ days will you see HGH flatting out[iii][iv].

The Difference Between Fat and Sugar

When free fatty acids (FFAs) enter the Krebs Cycle (the mitochondrial power plant) they enter a metabolic pathway called ‘beta-oxidation,’ which direct the FFAs through ‘ketogenesis’ that produces a ketone body called ‘acetoacetate’. This is then converted further into two other type of ketone bodies. (1) ‘Beta-hydroxybutyrate’ (BHB), which is the preferred fuel source for the brain and (2) ‘acetone’, that can be metabolized into glucose, but is mainly excreted as waste.

The equivalent to this process when burning glucose is called ‘glycolysis’ and the molecular product is ‘pyruvate.’ The difference is that, beta-hydroxybutyrate can create 25% more energy than sugar. That’s a lot when you consider the fact that this can be achieved in a fasted state as well.

Although a state of fasting ketosis is perfectly safe and has an array of health benefits to it, such as cellular repair, improved insulin sensitivity, reduced blood sugar levels and immense fat burning, you can’t maintain it indefinitely. Eventually, you’re going to have to eat.

Intermittent Fasting And Keto

The ketogenic diet is actually characterized as a fasting mimicking diet because it is physiologically very similar to a state of fasting ketosis. Nutritional ketosis can be established through nutrition as well, which still leads to an altered metabolic state.

A well-formulated ketogenic diet consists of the following macronutrient ratios: 70-80% fat (a boat load), 15-25% protein (moderate) and <5% of carbs (about 30-50 grams NET).

Intermittent Fasting and Keto Macros
Intermittent Fasting and Keto Macros

IF and Keto put your physiology into its prime-primal state. From the body’s standpoint, you’ll be constantly tapped into your greatest energy supply – your own body fat – and will thus have access to abundant energy 24/7.

But if Keto mimics fasting and IF puts you into ketosis, then why would you want to combine them? Couldn’t you get the same results if you just did one or the other?

The Biggest Reason Why Do Intermittent Fasting on Keto

The biggest reason why we should do intermittent fasting is that it increases longevity and improves lifespan. When you deprive any living organism of calories for a certain period of time, their expected life-span will increase by 30%. However, they will still starve to death because of them running out of energy for sustenance. That’s why the trick is to do IF periodically and at other times eat healthy nutrition that would still contribute to living longer.

The health benefits you gain from doing IF are very similar to that of Keto. However, there are still some characteristics unique to fasting which are unachievable by eating, even keto foods.

‘Autophagy’ is a metabolic pathway that causes the organism to ‘self-digest’ itself and removes waste material from the cells[v]. Autophagy is required to maintain lean body mass and it actually inhibits the breakdown of muscle in adults[vi]. It’s also needed for healthy brain cell mitochondria[vii]. In the process, inflammation throughout the body and overall oxidative stress get reduced[viii]. This fights against all illnesses.

Increased levels of glucose, insulin, and proteins all turn off autophagy. Even as little as 3 grams of the amino acid leucine can do so.

So, you would still want to occasionally do intermittent fasting on keto as well because it keeps your body healthy and well-sustained.

Keto IF Meal Plan

With all of that being said, you can definitely see that intermittent fasting and the ketogenic diet are perfect for each other. They are indeed a match made in heaven because they trigger almost the same physiological adaptations. What’s more, you’ll be also creating other characteristics that are unique solely to a fasted state. As a result, your overall health will improve and you’ll have access to energy 24/7.

The reason why you would want to combine them is that it will exponentially increase your body’s ability to burn fat. In my opinion, doing intermittent fasting on keto is the best and healthiest way of doing IF. By already eating a low carb diet, your body will be already prone to using ketone bodies and FFAs. This will make fasting effortless and actually more enjoyable than ever before. It gets so easy to fast for several days in a row without even getting hungry. This is tapping into your true prime-primal state of functioning where you’re stronger, more resilient and sharper.

If you want to combine these two nutritional strategies, then make sure you check out my program called KETO // IF. It’s an ultimate collection of knowledge about intermittent fasting and the ketogenic diet, including many other ways of increasing your vigor. In addition to that, you’ll also receive a 21-day meal plan and a fasting schedule, in which I tell you what to eat, in what amounts and at what time.


Click here to get KETO // IF and begin your transformation into the prime-primal state of your being.

P.S. I also offer nutrition coaching. Send me an enquiry at:


[i] Owen OE, Felig P, Morgan AP, et al: Liver and kidney metabolism during prolonged starvation. J Clin Invest 1969 Mar; 48:574-583

[ii] Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. J Clin Invest. 1988 Apr; 81(4): 968–975.

[iii] Merimee TJ, Fineberg SE: Growth hormone secretion in starvation: A reassessment. J Clin Endocrinol Metab 1974 Aug; 39:385-386

[iv] Palmblad J, Levi L, Burger A, et al: Effects of total energy withdrawal (fasting) on the levels of growth hormone, thyrotropin, cortisol, adrenaline, noradrenaline, T4, T3, and rT3 in healthy males. Acta Med Scand 1977; 201:15-22

[v] Short-term fasting induces profound neuronal autophagy. Autophagy. 2010 Aug 16; 6(6): 702–710.

[vi] Autophagy is required to maintain muscle mass. Cell Metab. 2009 Dec;10(6):507-15

[vii] Inflammation-Induced Alteration of Astrocyte Mitochondrial Dynamics Requires Autophagy for Mitochondrial Network Maintenance. Cell Metabolism Volume 18, Issue 6, p844–859, 3 December 2013

[viii] Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free Radic Biol Med. 2007 Mar 1;42(5):665-74.