Do you really need to drink 8 glasses of water a day?

It is an affirmation of the common knowledge that everyone knows and repeats as if it were a mantra: "Drink 8 glasses of water a day". Others prefer to drink between 2 and 3 liters of water daily. But does our body really need all that water or, on the contrary, does that recommended amount not be enough?
Lets start by the beginning. Surely you already know that the body is composed of almost 2 thirds of water . It sounds just as incredible as the fact that a lettuce contains more water than the juice of an orange. But it is like this.

The problem with the body is that it constantly loses water through various means, such as urine, feces, sweat or the very exhalation of air. And this water has to be replaced so that the body can perform its vital functions. Otherwise, dehydration would appear , which can lead to death.
Although it depends on many factors, such as the level of physical exercise or environmental temperature, it is estimated that adults lose approximately 3 liters of fluid each day.

So, do we have to drink 3 liters of water a day?
No, the truth is that no. The amount of water you should drink depends on the type of food you are carrying, since the food contains water. And a lot. Do you remember the example of the lettuce and the orange that we mentioned at the beginning? There you have it. Eating a diet rich in vegetables and fruits can bring almost a liter of water to your body. Soups (hot and cold), purees and creams, and foods cooked in water also count here. If even bread contains water! In addition, through breathing our body also generates a small amount of water.
Considering this, we could say that with a liter and a half of water, an adult in normal conditions would have enough.

The myth of the 8 glasses of water
The idea of ​​drinking eight glasses of water (equivalent to 2 and a half liters of water approximately) is an idea that became very fashionable to encourage people to drink more . However, this idea has been criticized by many experts who say that this idea has very little scientific basis. Many pushed it back arguing that it was just a way used by mineral water bottling companies to sell more.

Is it bad to drink too much water?
Contrary to what seemed like a popular idea that water is not safe , and that the more you drink, the better is that the excess of hydration is potentially problematic. Drinking too much water dilutes the salts (electrolytes) in the blood, which can cause hyponatremia (sodium concentration in blood below 135 mmol / L) and, in extreme cases, even death.

As for the supposed benefits that improve skin tone, reduces the risk of urinary tract infections, and other alleged health benefits, the truth is that they have no scientific basis to support them.

How to know if we have drunk enough water?
Our body is very good with its own, and it knows how to maintain the balance of water. The color of our urine is a good example of this. If we are dehydrated, the kidneys produce less urine and, being more concentrated, it is darker in color.

In any case, you know that for all these things of health control there are always technological solutions. There are several applications that help you to know how much water you should drink and that help you to follow a daily control. In this applications you enter a series of parameters that determine how much water (drink) you should drink. However, if you have a health problem, you should consult your doctor, to avoid problems.