Why do we need protein?

Like the structural steel of buildings and the metal meshwork in concrete, proteins provide the framework for every cell of the body. Just as workers at a construction site need a steady supply of building materials, tissues undergoing repair and those that are growing need a steady supply of protein to build and rebuild organs, muscles, antibodies, hormones, and enzymes - every kind of cell in the body. At eight months or eighty years, bodies need protein.

Protein is a reasonably worry-free food. Unlike fat or sugar, it's nearly impossible to overdose on proteins, especially in children's diets. And for most Americans, getting enough protein is not a problem. Also, unlike with fats and carbs, there's no such food as an unhealthy protein.