Combining Intermittent Fasting and Ketosis to Create an Optimal Physiological State

Siim Land

One of the most frequently asked questions I get – after how can I do so many things in a single day – has to do with combining intermittent fasting and ketosis. Can you do it and whether or not it’s any good? Read this article and you’ll find out.

The Quest

When it comes to nutrition, then the majority of people are on a quest towards finding that one diet or secret hack that would allow them to get everything their hearts desire – delicious meals, bulletproof health, excellent body composition, abundant energy, elevated mood and greater satiety. In order to get them all, you would think you have to sell your soul to the devil.

Which brings me to the nutritional strategies of intermittent fasting (IF) and the ketogenic diet (KETO). Both of them have gained a lot of rep in the health and fitness community – some of it is very good, some not so much.

IF and keto contradict almost everything that’s recommended by the general public in regards to nutrition. Despite that, there are millions of people getting amazing results from it.

However, there are others who can’t seem to make it work. After having coached many clients on how to combine intermittent fasting and low carb eating, I came to the conclusion that it’s indeed a very challenging and difficult ‘nutritionus[i]. The reason why most people fail is that they don’t have the slightest clue of what they’re doing. To mitigate that, I’m going to explain to you how it all works.

Meet Intermittent Fasting

In a society full of calories, ‘fasting’ has become the F-word that’s associated with images of starvation, obesity, anorexia, asceticism, and horror all at the same time. This is the result of contemporary eating habits based on snacking, refined carbohydrates and low fat bacon (yummm!).

What intermittent fasting really refers to is voluntary and controlled abstinence from food for a certain period of time. Usually, it means restricting your daily eating window but it can be done over the course of several times as well.

After not having eaten calories for about 6-8 hours, your body shifts out of a fed state into a fasted one, characterized by the conversion of stored body fat into energy. When this continues until the 16-18 hour mark, the liver’s glycogen stores will be completely emptied out and it now begins to produce more ketone bodies.

The Star of the Show –

If glucose and insulin levels remain low, the body will eventually shift into a state of ketosis, which restructures your metabolism to getting its main energy from fat and ketones, as opposed to carbohydrates.

But ketosis can be achieved by simply eating low carb for a certain time period as well. Keto is a fasting mimicking diet characterized by lower circulating blood glucose and elevated ketone body production.

Combining Intermittent Fasting and Ketosis
Combining Intermittent Fasting and Ketosis

Fasting ketosis – induced by fasting – and nutritional ketosis – achieved through eating – are physiologically the same – almost identical. There are some specific adaptations unique to a fasted state – like autophagy[ii] – which is why you would want to combine them.

The Benefits of Fasting on Keto

The two are a match made in heaven. In fact, the best way to intermittent fasting is to do it on a ketogenic diet because it will make your time spent in a fasted state that much more enjoyable and effortless.

There are still many other benefits as to why combining intermittent fasting and keto is a great idea:

  • Effortless fat loss – your body will be literally melting off its own fat because of it being metabolically geared towards doing it.
  • Reduced appetite and no hunger – because of the same reason you rarely get hungry or have sugar cravings.
  • Access to abundant energy 24/7 – similarly, you’ll be tapped into your largest fuel supply, namely your own body fat.
  • Low levels of inflammation – oxidative stress decreases significantly and you’ll experience less pain, slothfulness, and lethargy
  • Heightened focus and mental clarity – with no brain fog or tiredness, your cognition has the opportunity to flourish
  • Better health and protection against disease – both IF and keto have an array of therapeutic benefits that can cure many of your current medical conditions as well as protect you against them in the future.
  • Increased longevity and lengthened lifespan – the physiological state of both fasting and nutritional ketosis is so clean, which keeps your body well off for longer
  • An overall feeling of satiety and euphoria – with your body and brain constantly satisfied, you’ll experience general vigor and well-being.

Combining Intermittent Fasting and Ketosis

Now, with that being said, you would still want to combine fasting with keto for several reasons.

  • It takes 16+ hours to let autophagy begin its work and several days for it to really ramp up its effect.
  • Fasting is the easiest and safest way of getting into ketosis, but you can’t do it forever
  • Continuing to eat a ketogenic diet will help you maintain a state of nutritional ketosis for the majority of the time
  • If you do get off keto for a while, fasting is the quickest and surest way of re-establishing your fat-adaptation
  • Combining the two will increase your productivity while allowing you to enjoy delicious meals

With all of these benefits listed, it’s clear that ketosis has a huge metabolic advantage over any other way of eating. It puts us into our prime-primal state in which we’re completely self-sufficient and capable of producing energy despite the time, weather or how many calories we’ve just consumed.

How to Fast on Keto

Like I said earlier, people fail with fasting on keto because they’re clueless as to what goes on physiologically and how they can maintain it. They probably aren’t in ketosis, to begin with.

That’s why it’s essential to first go through a period of keto-adaptation. The reason is that if you were to start fasting right away you would have a bad time. If your body is still geared towards burning sugar, it will take a longer time to get into ketosis and the initial damage will be higher as well.

Fasting on keto should follow several stages of adaptation, during which your abilities to fast and burn fat change. They are:

  1. Ditching the Carbs – you first have to start eating a low carb diet for about 2 weeks, during which you practice milder windows of IF
  2. Revving up the Fasting – after about 1,5 to 2 weeks, you will begin to experiment with 24-hour fasts while still eating keto
  3. Going for the Long Haul – having had a few 1-day fasts, you start extending them past the 24-hour mark. You begin with 36 and 48 hours of fasting.
  4. Going (Fat Burning) Beast Mode – this is the point in which you’ve reached your full fat burning potential and are able to function well for 5+ days. Here you can fast for more than a week without being distraught by hunger or weakness.

Fasting and keto put us into our prime-primal state, in which we’re in our optimal physiological condition. They’re incredibly healthy and will increase our energy, performance, vigor, and well-being.

If you want to learn more about how to combine intermittent fasting with the ketogenic diet then check out my KETO // IF program. It teaches everything you need to know about these miraculous states and opens up new pathways of being previously remained unfathomable to us. In addition to that, you get a 21-day meal plan that will help you adapt and gives you a fasting formula.

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[i] Nutritionus – (noun) a word I just came up on the fly, meaning your habitual way of eating. Derived from the word ‘habitus,’ which refers to your everyday mode of being.

[ii] Autophagy – a metabolic pathway that makes the body self-digest itself by swapping out toxic chemicals and old proteins with new ones