High-quality nutritional sources: the scientific principle of consuming dairy products, legumes, and appropriate amounts of animal-based foods.

Dairy products, besides being rich in high-quality protein and vitamins, are also high in calcium with high bioavailability, making them an excellent natural source of calcium. The calcium intake from the diets of Chinese residents is generally low, averaging only about 50% of the recommended daily intake. Vitamin D deficiency is also prevalent among infants and young children in my country, which may be related to insufficient dietary calcium. Numerous studies have shown that calcium supplementation for children and adolescents can increase bone density, thereby slowing down bone loss. Therefore, the production and consumption of dairy products should be vigorously promoted. Legumes are a traditional food in my country, containing abundant high-quality protein, unsaturated fatty acids, calcium, and vitamins B₁, B2, and niacin. To increase protein intake in rural areas and mitigate the adverse effects of excessive meat consumption in cities, the production and consumption of legumes, especially soybeans and their products, should be strongly encouraged. Fish, poultry, eggs, and lean meat are good sources of high-quality protein, fat-soluble vitamins, and minerals. The amino acid composition of animal protein is more suitable for human needs, and its high lysine content helps supplement the lysine deficiency in plant proteins. Iron from meat is readily absorbed, while fish, especially seafood, contains unsaturated fatty acids that help lower blood lipids and prevent thrombosis. Animal liver is extremely rich in vitamin A, as well as vitamin B₁₂ and folic acid. However, some organs, such as the brain and kidneys, contain quite a lot of cholesterol, which is detrimental to the prevention of cardiovascular diseases. The average intake of animal-based foods is insufficient in many urban areas and the vast majority of rural residents in my country, and their intake should be appropriately increased. However, some residents of large cities consume too much animal-based food and not enough grains and vegetables, which is detrimental to their health. Fatty meat and animal fat are high-energy and high-fat foods; excessive intake often leads to obesity and is a risk factor for certain chronic diseases, so they should be consumed sparingly. Currently, pork remains the staple meat in my country, but it is high in fat, and the development of lean-type pigs should be promoted. Chicken, fish, rabbit, beef, and other animal-based foods are high in protein and low in fat, producing far less energy than pork. The consumption of these foods should be strongly encouraged, and the proportion of pork consumption should be appropriately reduced. A light, low-salt diet is beneficial to health; this means avoiding excessive oiliness, saltiness, and the consumption of animal products, fried foods, and smoked foods. Currently, urban residents are consuming increasingly higher levels of oil, which is detrimental to health. Salt intake among Chinese residents is excessive, averaging more than twice the World Health Organization's recommended intake. Epidemiological surveys show a positive correlation between sodium intake and the incidence of hypertension; therefore, excessive salt intake is not advisable. The World Health Organization recommends that each person's daily salt intake should not exceed 6g. Besides table salt, sources of dietary sodium include high-sodium foods such as soy sauce, pickles, and monosodium glutamate (MSG), as well as processed foods containing sodium. The habit of eating a low-salt diet should be cultivated from childhood.