The protein nutritional value of food depends largely on the number and proportion of eight essential amino acids contained in food. Only when the ratio of eight amino acids provided in food is close to the ratio needed by human body can we effectively synthesize human tissue protein, otherwise it will affect the utilization of protein in food. The World Health Organization put forward a ratio of eight essential amino acids needed by human body. The closer the ratio is, the higher the physiological value is. When the physiological value is close to 100, that is, 100% is absorbed, it is called total amino acid balance. Protein, which can achieve full balance of amino acids, is called complete protein. We can use this standard to score the protein of various foods for amino acids. The amino acid ratio of eggs and human milk is very close to that of human body, so it can be called food with balanced amino acids. Most foods are unbalanced in amino acid composition, so the nutritional value of protein is affected. For example, too high leucine in corn affects the utilization of isoleucine, and too high arginine in millet affects the utilization of lysine. Therefore, a plant-based diet should pay attention to the reasonable collocation of food to correct the imbalance of amino acid composition. If cereals and beans are mixed and made into soybean corn flour and soybean millet flour, the utilization rate and nutritional value of protein can be improved.
2. The calories and nutrients constitute a balance.
Carbohydrate, fat and protein can provide calories for the body. They are called calorie nutrients. When the total calories provided by caloric nutrients are in balance with the energy consumed by the body, when the intake ratio of the three caloric nutrients is 6.5: 1:0.7, the calories provided to the body are: carbohydrate accounts for about 60%~70%, fat accounts for about 20%~25%, and protein accounts for about10% ~/kloc-0. Excessive supply of calories and nutrients will cause obesity, hyperlipidemia and heart disease; Too little, resulting in malnutrition, will also induce a variety of diseases, such as anemia, tuberculosis, cancer and so on.
The three calorie nutrients are interactive. When the total calories are balanced, the proportion is unbalanced, which will also affect health. When carbohydrate intake is too high, it will increase the burden on the digestive system and kidneys, and reduce the chances of ingesting other nutrients. When protein provides too much heat, it will affect the normal function of protein, cause protein consumption, and affect the ammonia balance in the body. When carbohydrate and fat are in insufficient heat supply, it will weaken the protection for protein.
In order to meet the heat demand of life and work at all times, usually, the heat distribution of three meals a day should be: breakfast accounts for 30%, lunch accounts for 40%, and dinner accounts for 30%, so as to ensure the heat balance of the day.
3. Balance between intake of various nutrients
There are complicated relationships among various nutrients, and the requirements of nutrients are different in different physiological states and different activities, so it is difficult to grasp the balance between the intake of various nutrients. Therefore, the Nutrition Society of China formulated the daily supply of various nutrients. Accordingly, all kinds of nutrients in our diet should be kept within the range of 10% of the standard supply within a certain period. This mutual ratio can be called the basic balance between nutrients.
It is suggested in the pagoda of China residents' balanced diet that each person should eat (based on raw food) 300-500g of grain, 400-500g of vegetables and fruits and 100-200g of animal foods such as fish, poultry, meat and eggs (50g of fish and shrimp and 50-25g of poultry) every day.
4. Acid-base balance
Under normal circumstances, the PH value of human blood is kept between 7.3 and 7.4 due to its own buffering effect. People will maintain the acid-base balance of body fluids if they eat proper amount of acidic food and alkaline food, but if the food is not properly matched, it will cause physiological acid-base imbalance.
When food is not properly matched and acidic food exceeds the required amount in the diet, it will lead to blood acidity, blood color deepening, viscosity increase, and even acidosis in severe cases, and at the same time, it will increase the consumption of calcium, magnesium and potassium plasma in the body, resulting in calcium deficiency. This phenomenon is called acidic constitution, which will affect health.
Common acidic foods are: egg yolk, rice, chicken, eel, flour, carp, pork, beef, dried squid, beer, peanuts and so on.
Common alkaline foods are: kelp, spinach, watermelon, radish, tea, banana, apple, strawberry, pumpkin, green beans, cucumber, lotus root and so on.