I know there are calories in the yolk, and as Heather says, that's where the nutrients are but I wanted to addres the cholesterol myth. The warnings against eggs and their high cholesterol date from a time when it was thought that dietary cholesterol had a direct correlation with blood cholesterol. Science has come a long wat since then. Not only are the two not related but now we know there are two types of blood cholesterol and that eggs help with your "good" (HDL) cholesterol levels.
So don't throw out all your yolks without considering the goodness you are missing out on.
"Vision without action is a daydream ~ Action without vision is a nightmare"