It is best to eat one egg white a day, no more than two at most. Every 100g of egg white contains 60 calories, including 11.6g of protein, 0.1g of fat, 3.1g of carbohydrates, 9mg of calcium and 1.6mg of iron. The most important principle in nutrition is the principle of food variety. Although egg white is nutritious and contains a large amount of high-quality protein, which can supplement the body’s eight essential amino acids, as well as the right proportion and high content. However, it does not mean that egg white can replace other proteins, because each food has its own nutritional characteristics and very prominent nutrients. Egg white is relatively low in calcium, iron and other minerals, as well as vitamins, so a large intake of egg white will affect the intake of other nutrients, resulting in an unbalanced nutritional intake. It is recommended to eat one egg white a day, or no more than two a day if necessary. It is recommended to have a diversified diet and consume lean meat, fresh fruits and vegetables, coarse grains and other foods to supplement nutrition in a comprehensive way.