Water has no nutritional value by itself. However, if we can live up to several weeks without food, then without water - only a few days. During the day, the body constantly loses water, mainly in urine and sweat, and also during breathing. For the body to function normally, it is necessary to maintain water balance and replenish losses in time.
In this article, we'll explore why it's important to drink water and answer the popular and controversial question about your daily water requirement, based on scientific research.
Almost all chemical and physiological processes in the human body take place in aqueous solutions or together with water. Most of the water is contained in blood plasma - 92–95%, and the whole person is 60% water. It is thanks to the water that the blood performs its functions:
If there is not enough water in the body, the viscosity of the blood rises, the heart becomes harder to work and the state of health deteriorates sharply. That is why the body needs more water during active sports and high loads. Here are a few more examples of the benefits of water.
The brain is approximately 70% water and cannot function normally when it is not hydrated. Therefore, the lack of water in the body is extremely stressful. Drinking water on time reduces the risk of dehydration and stress.
Water forms saliva and helps break down food, making it easier for the food to pass into the digestive tract.
Muscle tissue is approximately 76% water, which helps to build protein in muscles and increase their volume.
Water is part of the synovial fluid, which lubricates and softens the joints and the cartilage surrounding them, preventing the bones from rubbing against each other.
Water acts as a building material for every cell in the body.
The first official statement on how much liquid a person should drink came in 1945 when the Food and Nutrition Board of the US National Academy of Sciences published its dietary guidelines: consume 2.5 liters of water per day, including liquid from foods. By 2021, almost all countries recommend drinking 1.5 to 2 liters of water per day in their national dietary guidelines. This figure is due to the fact that the kidneys filter almost 200 liters of blood per day, during which approximately 1.5 liters of urine is formed. That is why to maintain water balance, remove toxins and waste substances, you should drink at least 1.5 liters of water per day, and preferably more.
However, the WHO does not have an official recommendation for daily water intake. The reason is that there are many factors that can influence this figure.
Each person's needs differ depending on age, weight, physical activity level, general health, and even the climate in which he lives. The more water you lose through sweating, the more water you need to replenish. Therefore, naturally, a person doing hard physical work in a hot tropical climate will need to drink more water than someone of the same weight and height who spent the day in an air-conditioned office.
Perhaps the recommended eight glasses a day are just too much or too little for you. A 2016 study shows that the only way to determine how much water you need is simply to listen to your body. Water dilutes the trace elements contained in tissues and blood. If you drink more water than the body needs, the kidneys will not have time to remove excess fluid, and salts and other electrolytes will lose the ability to adequately conduct electrical signals. This condition is called overhydration or water intoxication and can cause seizures and even coma.
With a lack of fluid - dehydration - the filtration capacity of the kidneys also deteriorates. They begin to accumulate excess toxic substances. Against this background, various renal pathologies may arise. Research has shown that even mild dehydration can impair mood, memory, and brain function, as well as cause headaches and migraines.
Dehydration occurs when you lose more fluid than you can get from food and water. With a loss of 2-5% of fluid from body weight, a person is sharply thirsty. With an indicator of up to 6-10%, the head is spinning and hallucinations occur. If a person loses more than 10% of the fluid, he or she urgently needs medical attention.
A balanced diet and drinking regime can help prevent dehydration. Eat more vegetables and fruits, as they are high in water, and quench your thirst as soon as it starts. These are daily guidelines for most healthy people. Sometimes dehydration occurs for simple reasons: you don't drink enough, because you are busy, or because you don't have access to safe drinking water while traveling. However, there are more dangerous situations that increase the risk of dehydration.
The body loses water when sweating. If you engage in vigorous exercise and do not replenish fluid during exercise, you run the risk of dehydrating your body. Hot weather or high temperatures also increase the amount of sweating and fluid loss.
Severe, acute diarrhea and vomiting can cause a huge loss of water and electrolytes in a short period of time. This condition can be associated with undiagnosed or uncontrolled diabetes, problems with the genitourinary system, or taking diuretics, medications that cause frequent urination. In this situation, the body loses more fluid than usual. This means that in order to maintain the water-electrolyte balance, it is necessary to increase the amount of water consumed.
Obviously, every system in the body - from cells and tissues to vital organs - needs enough water. Soups, tomatoes, oranges, help fill the fluid deficit, but we consume most of the water from drinks. The latest scientific research proves that there is no magic formula for how many glasses of water each person should drink. The body itself will decide and tell you what will be the norm for it in each individual case. Your task is to listen to your body's desires and fulfill them in time. And the calculation of liters and the race for numbers can already be left in the past.
