Milk is a high protein food. Milk is one of the oldest natural drinks, known as "white blood", and its importance to human body can be imagined. As the name implies, milk is expressed from cows. Different countries have different grades of milk. Milk is rich in minerals, calcium, phosphorus, iron, zinc, copper, manganese and molybdenum. The most rare thing is that milk is the best source of calcium for human body, and the ratio of calcium to phosphorus is very suitable, which is beneficial to the absorption of calcium. There are at least 100 species. The main ingredients are water, fat, phospholipids, protein, lactose and inorganic salts. Milk is a high-protein food, which is called white blood. Milk is rich in protein, fat, vitamins, minerals and other nutrients, and milk protein contains essential amino acids. Milk is mostly short-chain and medium-chain fatty acids, which are easily absorbed by the human body. Potassium, phosphorus, calcium and other minerals have a reasonable proportion and are easily absorbed by the human body. Protein is an essential nutrient for human body, so we should pay attention to the intake of high-protein food in our daily life. Protein high food, one kind is milk, animal meat, poultry meat, eggs, fish, shrimp and other animal proteins; The other is the plant protein of dried fruits such as soybeans, mung beans and black beans, such as sesame seeds, melon seeds, walnuts, almonds and pine nuts. Because the types and proportions of amino acids contained in animal protein meet the needs of human body, the nutritional value of animal protein is higher than that of plant protein. In food, when the protein content of solid food is more than or equal to ≥20%NRV and liquid food is more than or equal to10% NRV, it can be said that it is high in protein. That is, ≥ 12g/ 100g (solid) or ≥6g/ 100ml (liquid), which can be declared as "high protein" or "rich in protein".