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

There are essential fatty acids (fats) and essential amino acids (proteins), but there are no essential carbohydrates. Why? Because your body can convert fat or protein into carbohydrates for the body to use. So, when you eat protein, your body can either use it for energy, or use it to build muscle – but not both. This is why weightlifters often eat carbohydrates AND protein, so the body isn’t wasting protein to use as an energy source.