Consuming plenty of water is said to be beneficial in flushing out toxins and keeping organs in good shape, resulting in weight loss and improved skin tone. Hmm, it turns out that this is only "considered". So how much water should a person drink per day?
The authors of a scientific review in the Journal of the American Society of Nephrology debunked some myths.
Myths about the he alth benefits of water
Water reduces appetite
Despite the fact that many people drink water before and during meals to reduce appetite, this does not work. No matter how much you drink, water passes through your digestive tract quickly and doesn't make you feel full because it doesn't help release the hormones that signal you're full.
Water removes various toxins from the body
It doesn't really matter how much water you drink: when you drink a lot of fluids, it causes you to produce more urine, but the excretion of various substances does not increase, only their concentration in the urine decreases.
But what about the "plentiful drink" in case of illness? Here folk wisdom confuses cause and effect. The patient needs a lot of fluid because he loses it with sweat and other secretions. And risk getting dehydrated. But water is not involved in the removal of decay products from the body, this is done by the organs of our body - with any amount of water in the body.
Water reduces headaches
This is belied by clinical practice and facts. Here again the tail and the beginning of the problem are confused. Headache MAY occur with dehydration, but drinking does not relieve it. Drinking enough water may prevent migraines, but it may not help, because migraines have dozens of causes and the amount of water per day has nothing to do with it.
Water consumption improves skin condition
In fact, water cannot moisturize the skin from the inside and linger in its layers. The condition of the skin depends on how much water evaporates from it. And this, in turn, depends on the overall he alth of the body, the temperature of the air around you and whether you use moisturizers. So the condition of the skin is unlikely to tell the rate of water per day.
It is good to drink 2 liters of water a day
The authors of the study do not find a rational explanation for such a widespread recommendation, since there is no scientific justification for this. And then, let's judge for ourselves - how can these notorious 2 liters be the recommended dose for everyone? Compare a girl weighing 42 kg and her mother at 86. And two liters of each of them? Just drink as needed.
And yet - how much water should you drink, if calculated by weight?
WHO does not give specific recommendations for water per day. However, there are several formulas on how to calculate the required amount of water per day for a person.
Most common: 30 ml per kilogram of body weight. This is enough to maintain a normal level of moisture in all organs and avoid dehydration. But there is a caveat: these calculations include not only clean drinking water, but also products containing it: watery fruits and vegetables, broths, compotes, milk, juice, tea, coffee, and so on.
The National Academies of Sciences, Engineering and Medicine of the United States have averaged water norm figures:
- Men - 15.5 cups a day (about 3.7 liters)
- Women - 11.5 cups (about 2.7 liters).
However, these recommendations cannot be accurate, because they also include all sources of fluid and do not take into account weight, body temperature, exercise level and human he alth. And the change in the rate of water consumption per day may depend on these factors.
"Household" common advice from the 70s: drink 6-8 glasses of water a day. It is more understandable to the layman and can be an approximate guideline, but again, taking into account the fact that not all the liquid consumed during the day can be measured with glasses.
How to drink water properly
- The main and main advice: by thirst. If the body signals that it wants to drink, then it’s definitely time to replenish the liquid in the body. Nutritionists have a saying: "If you want to eat, drink." This means that we often confuse hunger with thirst, and before overeating, try drinking a glass of water. Perhaps the body will get what it wanted, and you will easily give up extra calories.
- Another common and working advice: drink 2 glasses of warm water (approximately equal to body temperature) half an hour before meals in the morning. This is how digestion processes start, warm water is better absorbed and “works” in the body.
- If you exercise, be sure to drink 300-500 ml of water (depending on the load) half an hour before, during and after sports, so as not to dehydrate yourself with profuse sweating.
- Give up sugary sodas - they increase thirst and give the body a "sugar shock" and insulin surges. Also, do not get carried away with mineral water, in large quantities it can cause an excess of sodium in the body, which is harmful to the cardiovascular and other vital systems.
- Favour clean water between meals. The gastrointestinal tract must rest, and juices, compotes and other drinks contain fiber, sugar and other substances that the body perceives as food and, in response to their consumption, begins to secrete gastric juice. It turns out a big load on the digestive tract. Water is the best source of moisture.
- Don't be afraid of boiled water. Many copies have been broken in disputes about its harm and benefits, if very briefly: it cannot cause serious disorders and diseases, while it contains much fewer pathogens than raw water. Tap water in large cities definitely needs to be boiled, it is cleaned with chlorine-containing substances and when boiled, their concentration decreases.