Protein is the material basis of human life activities, is one of the important nutrients, the human body must consume enough protein, the body's cells to maintain normal operation. Protein consists of carbon, hydrogen, nitrogen atoms, some also contain sulfur atoms, the basic unit of its composition is the amino acids, amino acids are connected by peptide bonds. Proteins are found in the protoplasm of all animals and plants, and are important components of human blood, bones, internal organs, muscles, nerves and other tissues. In addition proteins also provide the body with calories, each kilogram of protein can provide the body with 4 kilocalories. Proteins in food are broken down into amino acids through digestion, and then absorbed and distributed through the bloodstream to the body's cells, which utilize these amino acids to re-synthesize the body's proteins.

In all foods, eggs are mainly protein-based, and the protein in eggs has the greatest nutritional value. Egg protein amino acid pattern, and the human body's protein amino acid pattern is the closest, easy to digest and absorb, essential amino acids by the human body to a high degree of utilization, its biological value of up to 95%. In the experiment, the protein in the egg is often used as the reference protein. Reference proteins are standard proteins that can be used to determine the quality of other proteins. On the contrary, one or several amino acids in the food content is low, can not meet the body's protein synthesis needs, resulting in other essential amino acids in the body can not be properly utilized, so that the nutritional value of protein is reduced, known as limiting amino acids. In order to improve the nutritional value of plant proteins, often two or more than two kinds of food mixed to improve the nutritional value of dietary proteins, the role of different foods to supplement each other's essential amino acid deficiencies, known as the complementary role of proteins, such as meat and soy protein can make up for the lack of lysine in the protein of the rice and noodles. Eggs and milk, fish, etc., as well as soy protein are known as high-quality protein. Protein is divided into animal protein and plant protein, nutritionists recommend that people in the diet to increase the appropriate intake of animal and plant proteins, in the animal protein preferred fish, shrimp and milk, eggs, in plant protein preferred soy.

Protein plays an irreplaceable role in human health. We are in the daily diet, eat which kind of protein, eat how much is very important, suffering from a variety of diseases of the population, especially important. Suffering from certain diseases for food protein intake should be limited, mainly the following groups of people.1. renal insufficiency, due to renal dysfunction, resulting in the accumulation of metabolites in the body, out of Shan azotemia. Protein metabolism needs to be excreted by the kidneys, renal dysfunction, metabolic waste accumulation will aggravate renal failure, so this group of people should be low-protein diet.2. Liver dysfunction of the population, such as cirrhosis of the blood ammonia elevated, due to cirrhosis caused by hepatocellular damage, blood ammonia elevation, which will lead to mental disorders, and even hepatic coma, this time should be limited to the amount of protein supply, especially animal proteins, meat production of ammonia, followed by eggs, dairy products and milk, ammonia production is the second, and should be limited in the supply of protein, especially animal proteins. Eggs produce ammonia, followed by dairy production of ammonia at least, so you can eat a little milk and some plant proteins. 3. protein allergy, some allergic people, after eating a lot of protein, skin redness, itching, eczema, and abdominal pain, diarrhea, such people should avoid eating a large number of protein-containing high food.