There are three mains source of fuel for our body ( for ours body cells to be more specific)
- Fat
- Carbohydrates
- Proteins
Since proteins are used by the body in cases of extremely calories defect ( not enough amino-acids for more important vital functions ), we use mainly fat and carbohydrates for energy.
But what is metabolic flexibility ?
Basically is the ability of our body to switch between carbs and fats and vice-versa.
So this is what happens:
- When we ingest carbohydrate, metabolic flexibility helps us control blood glucose, by burning glucose instead of fat
- When we ingest fat without carbohydrate, met flex helps us burn the fat instead of storing it.
- When we fast (and everyone “fasts” while they sleep), met flex helps us burn the fat stored on our butt, instead of becoming hungry for sugar or going catabolic.
- When we exercise, met flex lets us burn more stored fat and produce more energy at all levels of effort. We can run faster, jump higher, move more weight, and go longer on less food before we “hit the wall.”
Sadly, with a sedentary life of a bad diet, the metabolic flexibility might be impaired, this means that we are not switching between energy source as we should:
- We have higher and more rapid blood sugar spikes and crashes.
We all know this is unhealthy—but it also makes us more dependent on
stimulants and bready, sugary snacks to maintain our mood, our attention
span, and our ability to stay awake after meals.
- A continual demand for glucose at rest means we will become hungry much sooner after eating. Specifically, we become hungry for sugar and carbohydrate in order to “keep our energy up”
- Then, if we manage to ignore these hunger signals through willpower, our body is likely to reduce our energy expenditure
in response, making us feel tired and listless, and making weight loss
even more laborious. (At extremes, this can manifest itself as poor
cold tolerance, and other signs and symptoms of hypothyroidism.)
- Consequently, intermittent fasting and heavy caloric
restriction are likely to be both difficult and unsuccessful for the
metabolically inflexible.
Impaired fat oxidation contributes to insulin resistance, and a consequent inability to increase or diminish glucose oxidation.
How all this is going to improve our diet?
If our goal is fat-loss, then it could be a very good idea to optimize our metabolic flexibility in order to have better results in less time.
Moderate exercise can restore your ability to oxidize fat. Fat loss can restore your ability to absorb and oxidize glucose.
HIIT training could be a good choice.
Intermittent fasting could restore the cells ability to oxidize fat.
Low carbs diet could lead to a better insulin sensitivity.
Building muscles will enlarge the space for glycogen so we've got less probabilities to store glucose as fat.