Chicken eggs are the most common type of eggs that are used as a food source, although the eggs of ducks and geese are eaten as well. All of the parts of the egg are edible, although the shell is usually discarded. The white of the egg has a very different nutritional value from the rest of the egg.
Eggs may be prepared in a variety of ways. People who wish to avoid the large amount of cholesterol in the yolks can separate the whites from the yolks. The eggshell is carefully cracked in half without breaking the yolk. The whites are then poured into a container for later use while leaving the yolk in one of the halves of the eggshell.
This nutritional information is based on a medium-size chicken egg weighing 44 grams, or about 1.5 ounces. It also assumes that the egg is uncooked, and no ingredients have been added.
A medium egg contains 186 milligrams (mg) of cholesterol, almost all of which are in the yolk. This is 62 percent of the daily value (DV) of 300 mg for cholesterol.
A whole egg contains a total of 66 calories, of which 41 calories come from fat and 25 calories come from protein. The white contains 14 calories, all of which come from protein. No part of the egg is a significant source of carbohydrates.
An egg contains about 4.5 grams of fat, virtually all of which is in the yolk. Each gram of fat has 9 calories, so a serving of eggs contains 4.5 x 9 = 41 calories from fat. Saturated fats account for 1 g, and unsaturated fats account for the remaining 3.5 g.
An egg contains about 6.3 g of protein. Each gram of protein contains 4 calories, so a serving of eggs contains 6.3 x 4 = 25 calories from protein. The white contains 3.6 grams of protein, so the white from 1 egg has 3.6 x 4 = 14 calories from protein.