Protein is a core macronutrient that we need to ensure we get enough of every day. Protein is in every single cell in our bodies. It builds and repairs tissues, and is the building block for bones, muscles, skin, cartilage, and blood. Our body also uses protein to make enzymes and hormones. Protein does wonders for our bodies, especially when trying to lose weight. Eating enough protein helps you feel fully satisfied after your meals.