Egg white nutritional value is high because it’s rich in protein. An egg yolk makes 2/3 of an egg’s weight. Their protein value is 26g in an average cup of egg white and no fat or cholesterol. A medium cup of egg white has 117 calories, 17% sodium, 1% carbohydrate, 2% calcium and 1% iron. It’s healthy to eat one egg per day. Researchers say that people can consume even half dozens of egg white per day but not more than one egg yolk.