"There is only one good nutrient in this sandwich. It is protein."
protein
Carbohydrate Fats Protein
It means that the presence of the carbohydrates, spare the use of protein for energy use. Hence protein is use for body-building and not use for energy-giving.
protein
I would imagine protein.
this means that the body will use carbohydrates as a source of energy when it is supply in sufficient quantities
calcium and protein
It is a protein
no. It is a nutrient.
I am pretty sure that it is protein. Protein help build and repair muscle and tissue.
When your body needs energy, it will first use carbohydrates stored in your body, sparing the protein and fats in your body. When the stored carbohydrates are depleted, the body will start using protein and fats.