We need protein for building muscles. We get calories from protein. Is the protein not burned to produce the calories or does the burning leave the amino acids we need intact?

Question

We cannot just have carbohydrates to burn for calories. We need protein and fat. Which presumably means we do not just burn them for calories but need some part of them intact.

So do we not burn them for calories? Do we burn part of them for calories and use other parts intact? Does the calorie count include just the part we burn or do we count the other parts we use for calories?

In: Biology

Answer 1

Burning calories of any of the carb/protein/fat for energy is just creating a chemical reaction with excess energy that your body uses as energy. Nothing is ‘burned away’ as all components of the original are left in tact (conservation of mass) but are now in different forms. Carbs and fats go to water and carbon dioxide that leave your body in various orifices. Proteins are broken down into amino acids that your body then uses for various things.