Water is the most abundant substance that makes up the human organism, accounting for about 50 percent or more of an adult's body weight, and for infants before the age of one, it accounts for 75 percent of an infant's body weight. Water cannot directly provide energy for the human body like proteins, fats and carbohydrates, but it is a more important substance than these nutrients for life activities. Without a supply of water, the human body can only survive for a few days, whereas with other nutrient deficiencies, the human body can survive for weeks to years, so there is no life without water.
As the saying goes: sufficient water, all diseases. So people must consciously replenish water every day, especially the elderly, less sensitive to water loss, more attention should be paid to timely and appropriate water.
Drinking water is a way for living organisms to take in water through the mouth, and the human body takes in about 2 liters of liquid through the mouth every day. Water is mainly absorbed in the stomach, and when it enters the body, the water is mainly used to replenish intracellular and extracellular fluids, which are involved in various physiological activities of the human body; therefore, drinking water is an important part of maintaining the metabolism of living organisms.
Water demand is mainly affected by age, environmental temperature, physical activity and other factors. The amount of urine excreted by the human body in a day is about 1,500 milliliters, plus water lost from feces, respiration and skin, etc., the total **** consumption of water is about 2,500 milliliters or so, so, healthy adults need about 2,500 ml of water per day, of which drinking water accounts for about 50%, the water contained in the food is about 40%, and the body metabolism produces 10% of the water. Lightly active adults living in mild climates should drink a minimum of 1200 ml of water per day, which should be increased appropriately under conditions of high temperatures or strong physical labor. Drink more water when you are sick, especially when you have a fever, because your metabolism speeds up by about 7% for every 1° rise in body temperature.
When dehydrated, in addition to feeling thirsty, there will be dry skin, cracked lips, weakness, urination, dizziness, headache and other phenomena, and in severe cases there will be fever, irritability and other mental symptoms. Insufficient water will lead to malfunction of gastrointestinal digestion, blood transport of nutrients, body fluid concentration regulation, etc., and will also trigger back pain and deformity of the knee, arthritis and other diseases.