Water is the most abundant substance in human body, accounting for more than 50% of adult's weight. Before the age of one, the water content accounts for 75% of the baby's weight. Water can't directly provide energy for human body like protein, fat and carbohydrate, but it is more important for life activities than these nutrients. If there is no water supply, the human body can only survive for a few days, while without other nutrients, the human body can survive for weeks to years, so there is no life without water.
As the saying goes, adequate water can cure all diseases. Therefore, people must consciously replenish water every day, especially the elderly, who are not sensitive to the loss of water, and should pay more attention to drinking water in time and in moderation.
Drinking water is a way for organisms to absorb water through their mouths. The daily intake of liquid through the mouth is about 2 liters. Water is mainly absorbed in the stomach. After water enters the human body, it is mainly used to supplement intracellular fluid and extracellular fluid, and participate in various physiological activities of the human body. Therefore, drinking water is an important part of maintaining biological metabolism.
The demand for water is mainly affected by age, environmental temperature, physical activity and other factors. The amount of urine excreted by human body in one day is about 1500ml, and the water lost from feces, breathing and skin is about 2,500ml. Therefore, the daily water demand of healthy adults is about 2,500ml, of which drinking water accounts for about 50%, water contained in food accounts for about 40%, and water produced by metabolism in the body accounts for 10. Adults living in mild climate and less physical activity should drink at least 1200ml every day. Under the condition of high temperature or strong physical labor, it should be increased appropriately. Drink plenty of water when you are sick, especially when you have a fever, because every time your body temperature rises 1, your metabolism will accelerate by about 7%.
When water is scarce, besides feeling thirsty, there will be dry skin, cleft lip, fatigue, less urine, dizziness, headache and other phenomena, and in severe cases, there will be mental symptoms such as fever and irritability. Insufficient water will lead to gastrointestinal digestion, blood nutrition, body fluid concentration adjustment and other functional disorders. And it can also cause back pain, deformed knee joint disease, arthritis and other diseases.