I think protein is the most important nutrient because...
You depend on protein to sculpt your growth and development. Without protein, you wouldn't be who you are today; or near as healthy. You can find protein in meat and veggie sources.Eggs are great protein along with poultry and most vegetables. It has essential amino acids in it that your body needs to function properly. (your body can't produce these specific amino acids) All of the amino acids your body needs are in meat. Only some of them are in vegetables; so for vegetarians it is acceptionally hard for them to recieve the amino acids they need on a daily basis. They have to double the amount of protein they eat and mix and match the right amino acids together to get the same amount of protein as someone who eats meat. Protein is a major energy provider. Without protein athletes wouldn't be able to perform the way they do. I don't think people realize how much we need protein.