Metabolic flexibility is one of our most essential skills in adapting the human body to its food.
In short, metabolic flexibility is a critical factor in your metabolism. It is the ability to shift from one fuel source to another. Specifically, metabolic flexibility is the human body’s ability to alternate between fat and carbohydrates based on their availability.
But it does not come from now. For many years we have had to do pedagogy and dissemination about the fact that ketosis is a natural state of the body and that the ketogenic diet is an excellent tool, among many other things, to regain the ability to mobilize the fat and achieve this body state.
Now, the ketogenic diet is a wonderful tool, but it’s not the only thing you have to do all the time.
Today the time has come to highlight that it is not the only metabolic state that will allow us to be healthy.
When is it good to use fat, and when is glucose?
The variability and the ability to use different energy substrates according to the environment’s demands allow us to react in the best possible way in each situation. For example, ketosis is optimal to fight a bacterium, and instead, in the early stages of a viral infection, we require glucose.
The state of ketosis is optimal to run long distances and glycolysis for the sprint to finish.
The state of ketosis is induced in physiology in a part of the menstrual cycle, and instead, it is not the most desired in the first part of the process if you want to get pregnant and as we have explained in detail in this video.
Although there are nuances, and one can always be in ketosis and draw on glycogen stores when the situation requires it, the key is Metabolic Flexibility and easily switch from the use of glucose and fat.
Metabolic flexibility
Of course, this ability or flexibility is not accidental. During evolution, environmental fluctuations forced the human species to develop a metabolism capable of adapting its energy needs to various climatic, seasonal, and vegetation.
👉 Metabolic flexibility protected human survival regardless of food availability. What I usually call “Survival of the most flexible.”
At the time, acquiring that ability was inevitable (those who did not die). The point is that evolution, very much hers, transforms the unavoidable into a necessity.
It is known that metabolic changes are trained, and if we spend too much time in one state, it is difficult to pivot to the other.
👉 It is what is known as cellular memory.
Ketogenic diet is an “artifact”
Remember that the ketogenic diet is an “artifact” that attempts to simulate what was previously unavoidable. In the past, we produced ketones when we were fasting or when carbohydrates were lacking (such as in winter periods), and we also sometimes got berries or cooked root vegetables.
In short, life is uncertain, and keeping the different possibilities of metabolic response, “sharp” makes us calm.
Once this metabolic flexibility is recovered simply by following the rhythm of meals that are not natural, between at least 12 and 16 hours of daily fasting between meals, we will visit all the same day’s metabolic spaces.
Therefore, the ketogenic diet is not the end but a tool to maintain metabolic flexibility.
👉 Any nutritional strategy carried out for too long can lead to a loss of metabolic response capacity.
In a context where it is recommended to eat 6 times a day, meal schedules are followed that alter our circadian rhythms, and usually, all intakes are rich in carbohydrates. The first approach to recovering metabolic health is almost always intermittent fasting and a ketogenic diet.
And it’s funny because one of the significant advantages of the ketogenic diet is getting you out of the status quo of always using glucose as your primary energy source. But being in ketosis all the time is entering a new status quo that will reduce your metabolic flexibility again.
Once your body regains the ability to mobilize fat, the key will be variability.
How to add variability for metabolic flexibility
Keto periods and periods in which we increase the consumption of healthy carbohydrates.
The key is that any dietary approach must meet the following:
- Based on natural foods and not on processed products: Consider anything with more than 5 ingredients as a product.
- With an excellent nutritional density. (Include offal, fish, vegetables, eggs, and fruits) study
- Low or very low in foods with inflammatory potential: Mainly cereals and dairy products.
- Therefore, if your goal is to gain health, freedom, and the ability to respond to the environment, an approximation would be Keto periods (sometimes long: 3-6 weeks, others: 5/2) and periods in which we base our diet on food and not products, avoid inflammatory nutrients, and moderate carbohydrates at night. All this always in the context of intermittent fasting.
Our proposal to recover your metabolic health:
👉 Phase 1
- 2 months of ketogenic diet and incorporation of intermittent fasting
- Incorporate the ketogenic diet to remind your body how to mobilize its reserves.
- Maintain intake windows of at least 12 hours maximum and shorten your intake windows as you see yourself able to tend to a 16 hour fast 8 intake rate.
- Before moving on to the next phase, write down how you feel and the benefits you have obtained from these two months of the ketogenic diet.
👉 Phase 2
- 2 months. Add fruit and tubers and see how it suits you. Maintain the rhythms of intermittent fasting and low-carb dinners as much as possible.
- Re-analyze how you feel before moving on to phase 3.
👉 Phase 3
- 1 month Get back on the ketogenic diet, experience one or two days a week of fasting 23-1
- At this point, you have managed to re-educate your metabolism completely. It is time for you to decide based on your experiences which metabolic state you want to be in according to your situation, social context, and environment demands. You can move from one state to another without problems.
To include metabolic flexibility in your life:
- January February: Keto diet.
- March-April-May: Protocols 5-2
- June: Pre-summer Keto
- July-August: Natural medium carb diet
- September: 1 month of keto
- October November: Natural medium carb diet
- December: Free and more permissive.
As a veteran fitness technology innovator and the founder of GearUpToFit.com, Alex Papaioannou stands at the intersection of health science and artificial intelligence. With over a decade of specialized experience in digital wellness solutions, he’s transforming how people approach their fitness journey through data-driven methodologies.