A person can live for 3 weeks without food; Without water, it can survive for 3 days; Without air, it can only survive for 3 minutes. It can be seen that water is an important substance for human body, second only to air.
Water is the most abundant substance in human body, accounting for 60%~70% of adult weight. Most substances in blood are water, and our muscles, lungs, brain and other tissues and organs also contain a lot of water.
Role of water:
1. It is a good solvent for a variety of minerals, microorganisms, glucose, amino acids and other nutrients, and participates in the material transport in the body. It transports nutrients into cells, and also transports metabolic waste in the body.
2. The main component of the body temperature regulation system, the heat generated by energy metabolism in the body, is transferred to the skin surface through body fluid, and the excess heat is taken away by evaporation or perspiration to keep the body temperature constant.
3. Lubrication: joint lubricant, saliva, gastrointestinal mucus secreted by the digestive tract, mucus in the respiratory system airway, and mucus in the urogenital tract can not be generated without water.
There are three sources of water:
We get the water we need by drinking water, food and raw water in the body every day. Drinking water includes white water, tea, drinks, etc. obtained from various ways. We can get a lot of water by drinking water; The diet of Chinese residents is mainly vegetable food, and fruits and vegetables contain a lot of water; In addition, our common cooking methods are different from those in the West. Most of them are steaming, stewing, boiling, and frying. They not only retain most of the water in the food, but also often add a certain amount of water when cooking. Therefore, we can obtain a certain amount of water from the food. The survey found that urban residents in China get 40% of the water from food every day and nearly 60% of the water they drink.
The endogenous water in the body refers to the water generated by the metabolism of three major energy producing nutrients (protein, fat and carbohydrate) in the body, and is also a way for the body to obtain water.
There are four paths for water:
We lose water through urination, defecation, exhalation, skin evaporation or sweating, of which urination is the most important way. There is a water balance regulation system in the human body, which ensures that the fluid intake and loss are in a dynamic balance state. When the body has insufficient body fluid, the thirst center is stimulated, resulting in thirst and drinking behavior; If the missing water cannot be replenished by drinking water in time, the body will increase the secretion of antidiuretic hormone and aldosterone, causing fluid retention in the kidney, and maintain fluid balance in the body by reducing urine output. If the water intake is high, the water will be discharged by increasing the urine output.
The body lacks water more than 1% of its body weight, and some symptoms will occur if it is not replenished in time. In addition, there are also well recognized symptoms that mean your body is already in a state of water shortage, such as joint pain, muscle pain, back pain constipation ； The urine has a strong smell and yellow color.
How much water do we need to drink every day?
Adults who live in mild climate conditions and engage in mild physical activity need to drink 1500-1700 ml of water every day.
When we have a large amount of activity, the water loss increases, and we should appropriately increase the amount of drinking water. For a short time of exercise, an additional 400~600ml of liquid can be added to make up for the lost water; However, if you continue to exercise violently for more than 1 hour, you need to add more liquid. In addition, the hot environment makes the perspiration increase. Turning on the air conditioner or heater indoors or on the plane can cause the evaporation loss of water in the skin, which also needs to increase the amount of drinking water. Drinking alcohol will accelerate the metabolic reaction in the body and increase the urine output. There is no fixed amount of drinking water that should be added, as long as the water balance in the body is maintained.
Drink water at any time, a small amount for many times
The time for drinking water should be allocated at any time of the day. In principle, a small amount of water should be consumed many times, about 200 ml each time. A night's sleep will lose a lot of water. Although there is no thirst after getting up, the blood in the body is still sticky due to lack of water. Drinking a cup of cold boiled water (150ml) after getting up in the morning can reduce blood viscosity and increase circulating blood volume.
For many years, we have taken it for granted that only when we are thirsty does our body need water and drink water. In fact, when the body is thirsty, it is already in a state of water shortage, and began to use the regulating system to adjust the water balance. At this time, although drinking water can supplement the lost amount, it is not the best time to drink water, and it is often easy to drink a lot of water at one time, increasing the gastrointestinal burden, diluting gastric juice and affecting digestion.
