How much water should you drink? The answer is not 2 liters a day
One of the most persistent recommendations is that of ‘ drink a lot of water ‘. You hear it from doctors, nutritionists, trainers … it seems that there is division of opinions in everything, except in the idea that we should be constantly drinking.
“Your body is 60% water , you should drink at least 2-3 liters of water a day , at least 8 glasses of water a day , your urine should be very clear …” Do these messages ring?
They are so repeated that we take them for granted. The result is bottles of water in all jobs, Gatorade every kilometer in popular races, everyone with their bottle in the gym … and of course, a very happy industry that sells bottled water at the price of gold .
Although it’s hard to believe, these recommendations have little scientific support(like the idea of 5-6 meals a day ). No matter how hard you look, it will cost you to find some foundation.
Some observational studies find a minimal reduction of cardiovascular disease in those who drink 5 or more glasses of water daily, well below the general recommendations, and there is no conclusive information regarding the impact of water intake in several types of cancer.
Multiple studies show no health benefits from increasing water intake, and a comprehensive review of many studies related to the topic concludes ” There is no clear evidence of the benefits of increasing water intake .” Recognizing that it is not the same absence of evidence as evidence of absence, it also concludes ” there is no clear evidence that there is no benefit “.
But to be such a widespread recommendation, the lack of evidence seems to me quite … evident , especially when the underlying message is: Do not trust your thirst .
WHY I DO NOT BELIEVE IN THE GENERAL RECOMMENDATION
It is unnatural
Our body has an exquisite hydration sensor , a refined homeostatic mechanism during millions of years of evolution.
If it is as unreliable as they would have us believe, it is incredible that we have survived all this time without having canteens or bottled water, quite a feat.
The recommendation to drink “x” liters of water per day promotes the idea that we should ignore the basic messages of our body. Are you not thirsty? It does not matter, keep drinking because you have not reached your daily quota . Do not worry if you have to go to the bathroom every two hours or if your bladder wakes you up in the middle of the night.
And speaking of bladders, you will have also heard the recommendation that the urine should be very clear. Several studies find no relationship between the color of the urine and the state of hydration, beyond the first of the day. Unless you see something strange, do not get obsessed with color.
My opinion is that when we launch a message to the public that contradicts our nature (such as drinking without thirst), we must have solid proof that it is a good idea. In this case, they do not exist.
It can interfere with digestion
It is not advisable to drink a lot of water with food. Your stomach needs an extremely acidic environment to digest food. If you flood it with water, you dilute the gastric juices and therefore its capacity to digest, apart from reducing effectiveness to the elimination of possible pathogens (another benefit of low pH of the stomach). If you have digestion problems, reduce the liquid in the food.
It makes us forget about food water
Food should be an important source of water. Vegetables are mainly water. The fruits too. Even meat, fish and eggs have a high percentage of water.
And if you take a cream / vegetable soup or a broth of bones , you get not only hydration, but also nutrition .
We can not say the same about cereals , whose contribution in water is very low, apart from causing greater fluid retention in our body, especially if they are refined.
It can alter the balance of electrolytes
Our body requires specific proportions between certain minerals, such as sodium and potassium . It also expects a specific concentration of these minerals in blood . An excess of water dilutes that concentration, which together with modern fear of salt makes drinking too much can lead to an imbalance of electrolytes.
You can overhydrate
Just as the benefits of fasting are not promoted because they do not help sell anything, the industry prefers to bombard us with the risks of not drinking enough, but they forget to alert us to the dangers of drinking too much.
The poison is in the dose, and it is literally possible to get intoxicated with water . The hyponatremia , as is known this is indeed a real danger. More runners die of hyponatremia than dehydration.
Without reaching these extremes, a constant excess of water, with a very low salt diet, can reduce blood sodium levels enough to produce long-term negative effects, such as bone fractures and heart attack. of myocardium .
No one will get hyponatremia from drinking 2-3 liters of water, but forcing yourself to permanently consume more water than you need is probably more harmful than drinking just when you’re thirsty.
Another typical argument to recommend increasing water intake is that it improves the function of the kidneys, helping to eliminate toxins. Although there is no information to deny it, several studies question this idea. A review of current studies ends with the inconclusive ” more research is necessary “, and there are even studies that associate a greater hydration to the reduction of the glomerular filtration rate.
What does seem clear, is that drinking more water exposes you to more potentially problematic compounds . Fluorine or chlorine in the case of tap water (with meta-studies that associate the intake of chlorinated water with certain types of cancer), and some xenoestrogens such as Bisphenol-A in bottled water.
I do not want to be an alarmist or that now you are afraid of water, it just lacked :), but introducing more toxins in your body unnecessarily is … ehhh, what is the word … unnecessary.
And this without mentioning the enormous waste associated with bottled water, one of the great businesses of the century . Most of the bottled water we drink is nothing but filtered tap water. For your own good, and that of the environment, buy a house filter better .
Water is water
The water in the food is water. The water in milk , coffee or tea is water. Even the water in Coca-Cola (argh!) Is water. Some experts say that to meet your daily quota you should only count pure water. This is absurd.
And of course do not fall for the water with oxygen , water penta or alkaline water . Water is water, and I doubt we can improve its formula (H2O), no matter how hard we try.
DRINKING WATER THINS?
Of direct way, obviously not, but we could say that it helps in two aspects related to the thinning:
- Drinking cold water slightly accelerates the metabolism, and undoubtedly your body burns some extra calorie to heat it (but it is much more effective to bathe in cold water ).
- Drinking water before the meal provokes a satiating effect , decreasing the calories consumed. This seems to work in adults, although the same effect is not found in young people.
If your goal is to lose weight, drink a glass of water 30 minutes before eating (as indicated on the day trap ), can help you eat less. Remember that during the meal or immediately after it is better not to drink too much, so as not to interfere with the digestion.
But do not put your hopes in the water. The effect is very limited. Drinking a lot of water is not the secret to losing weight. Eat well, yes .
HOW MUCH WATER DO YOU REALLY DRINK?
To be clear: I have not dealt much with the subject until now because there are traditional recommendations much worse than drinking more than necessary .
But here goes my proposal, totally innovative: Drink when you’re thirsty.
If thirst takes you to drink two liters of water a day, perfect. If it’s 3 liters, it’s probably because you need it.
And as always, experiment. Some people feel better when drinking something else. If it is your case, go ahead. Others feel that by drinking more digestions are worse, or they are more difficult to warm up ( cold hands and feet ). In that case, do not do it.
The bottom line is that when we take a general recommendation as a dogma, without questioning its origin or the interests behind it ( cui bono ), we simply endure a myth and allow them to continue to profit from our health.
No animal needs hydration guides. Drinking when you feel thirsty is the best recommendation .
If you are one of those who need more specific rules, I would say that if you urinate more than 5-7 times a day and / or get up at night to go to the bathroom, you are probably drinking too much.
I do not deny that certain circumstances make it advisable to drink something more than what the body asks of you, but it is that, exceptional circumstances, not the rule. For reviewing the most typical cases:
- At the beginning of a ketogenic diet it is normal to lose a lot of water, when consuming glycogen reserves. Electrolytes are also lost with this water. Although thirst often accompanies this process, it is advisable to drink more water than usual and be more generous with salt.
- Kidney stones . Before we saw that the idea that an increase in water intake is beneficial to the kidneys is very questionable. But in case there are indications of calculations, it does seem that taking more water helps.
- Anticipation of a high loss of water . If you are going to run a marathon in the summer, it is probably best to start the race with more fluid than usual.
- Elderly . Although some studies do not find benefits when increasing the water intake in older adults (55-75), others indicate that thirst sensation loses reliability with age. For caution, it may be advisable for older people to drink from time to time without thirst.
- Pregnancy and lactation: It is a general recommendation to increase the water intake in these cases. Although I have not found any support study, it is reasonable to think that with all the hormonal changes associated with this stage, drinking more can be positive. On the other hand, it is also especially important to reduce chlorine.
Until the 70s, the recommendation for distance runners was that they drink little, for fear that the extra weight and excessive perspiration would slow them down. The positions of drink (water) in the marathons were scarce, and of course they were not considered necessary in the first half of the race. Completing a marathon without water was in fact the ultimate goal, the real fitness test.
In spite of not having evidence that this practice was dangerous, the manufacturers of sports drinks decided at that time that they were going to convince us of two things:
- We can not trust our thirst.
- Water is not the best drink to hydrate.