One thing that I would like to clarify since a long time and never saw anyone talking about it... if someone can tell me if I'm wrong in my understanding that would be appreciate.
We know that 1g of protein = 4cal and unless I'm wrong your body has to 'transform/burn' that gram to actually release the energy from it... but since proteins are not the preferable source of energy of the body, it is more likely to be used as building blocks for muscles, cells, organs, blood, etc... so it doesn't have a double action, ie be used as a 'block' and also release energy, it's either one or the other, the body will not have 4cal out of the protein if it's used as material, right ? And the other way around is the same, if the body use the protein as energy, you loose this 'material' for further use.
For example, if I eat 50g of carbs, I will have 200cal for sure, since it's fuel and there is no other use for carbs beside fuel.
But if I eat 50g of proteins, I might have, let say hypothetically 10% of them used as fuel by gluconeogenesis and the rest used to repair/build tissues, so I will only get 20cal from those proteins instead of 200, since most of them are used as materials.
In other word we do not really get the calories from the proteins because we are using them for other purpose then fuel, yes it is potentially fuel, but unless the body decide to use them, it's materials.
Fat would be in between proteins and carbs, since we use some for the body, cells, hormones, etc... but not as much needed as proteins, so a lot of it is use as fuel/energy.
Am I making sense ?
This is another reason why in my mind 'a calorie is a calorie' doesn't make sense at all, since one macro is 100% fuel and the 2 others can be used as material instead of energy.
Eric
