How much water to drink per day: tips and myths

Posted on Jun 26, 2022      358

How many liters of water should a person drink per day? If you are interested in the answer to this question, you’ve come to the right place. Article about water without water.

Water is essential for human life. It ranks second in importance, with oxygen in the first place, of course. However, the water balance in the body is surrounded by a lot of myths.

Nutritionists, “experts” on healthy lifestyles, from blog to blog, from book to book, transfer to most of the myths. So how much water should you drink per day and how to do it right?

A major myth about water balance

How many glasses of water should you drink a day? For years, we’ve been constantly told that the body gets dehydrated. And the body needs to drink at least 8 glasses of water a day to function optimally.

But some counselors have gone further: they advise to drink 2.5 to 3 liters a day. And the reward for such a daily feat is healthy skin and the prolongation of youth. No, you do not need to force yourself to drink such a huge amount of fluid.

This myth comes from the United States. Researchers of the American Association of Food and Nutrition Board stated back in 1945 that an adult should consume 1 ml of water for every calorie of food. This added up to 2.5 liters per day for men and 2 liters for women.

So many years later, few people are trying to dispel the myth. But today’s experts have missed an important detail: the same researchers from the Food and Nutrition Board also said that most of the water is already contained in food.

About 1.5 liters we get with any liquid, and another liter, as part of any food, so it is unnecessary to drink just water in pure form. It is in every product.

How much water do we need to drink per day?

But if not eight glasses, how much? Individual hydration needs depend on personal parameters: weight, height, environmental factors, level of physical activity, and so on.

However, there are certain recommendations for fluid intake. The Institute of Medicine of the U.S. National Academy of Sciences estimates men should consume about 3.7 liters of fluid per day, and women about 2.7 liters.

The scientists also state that any kind of liquid (coffee, tea, juice, etc.) is counted, even the liquid in the food. The same study also says that individual needs for water vary and there are no uniform norms of fluid intake.

For example, when the body detects that there is not enough fluid, it releases the antidiuretic hormone vasopressin. It increases water uptake in the kidneys and returns to the bloodstream to restore balance. But when that’s not enough, either, the body turns its attention to itself and makes you thirsty. Surely you will react and drink a glass of water.

But if you drink 2-3 liters of water, you can live longer.

There is no scientific proof of the false fact that 2.5 liters of water per day increase life expectancy. A study of over 120,000 volunteers was conducted in the Netherlands for about 10 years.

The results were published in the British Journal of Nutrition: The scientists found no direct link between fluid intake and causes of death. People who drank a lot of water and those who drank little died of the same diseases.

Some people think you should drink water according to your weight. This is partly true, but as we said, most of the norm is contained in food, and weight is not the only factor. In such a situation, the amount of liquid getting into the body is difficult to calculate, and you have to rely on thirst.

Why you need to trust the body

Manufacturers of drinks actively continue to instill in people the rule of two liters or eight glasses a day. No wonder, because selling the fear of dehydration is very profitable.

Until recently, humans and almost all terrestrial animals had to develop and adapt with inconsistent access to water. Therefore, a system to maintain fluid balance was a necessity, especially in times of drought.

Times are different now. But the body still sends you a signal, using a handy and virtually failsafe tool to measure (dehydration) - thirst. If you’re thirsty, drink. It’s as simple as that.

What happens if you drink a lot of water

Is it possible to drink too much water? Although it sounds fanciful, it really can. Excessive water consumption can lead to so-called water intoxication, in which there is a serious decrease in the concentration of sodium in the blood (hyponatremia).

Symptoms of hyponatremia can range from nausea and confusion to seizures and impaired coordination of movements.

However, cases of water intoxication are quite rare. Professional long-distance runners who lose track of the water they drink during a race are primarily at risk. But there are also those who drink large quantities of water to win an argument or a contest.

In 2007, there was an accident at a radio station in California. A woman drank 6.5 liters of water to get a game console. Five hours after the contest ended, she died of water poisoning.

Excessive water consumption can lead not only to water intoxication but also cause several other problems. Warns that drinking too much liquid can:

  • Increase protein breakdown;
  • provoke a washout of vitamins and trace elements from the human body;
  • overload the cardiovascular and urinary systems.

If a person has diseases of the cardiovascular system and kidneys, and drinks a lot of water (over 2-2.5 liters of liquid), this can lead to serious consequences.

This is another reason to trust your body. If you rely on thirst, you are unlikely to encounter water poisoning and other consequences.

What happens if you don’t drink enough water?

What happens if we drink less water than our body requires? 

When dehydration can develop:

  • headache;
  • fatigue;
  • loss of appetite;
  • redness of the skin;
  • dizziness;
  • dry mouth;
  • dry eyes;

burning sensation in the stomach.

Also in the article on the benefits of water, we wrote that sufficient daily consumption of water:

  • improves brain activity;
  • increases physical activity;
  • It improves digestion and joints;
  • reduces the risk of urolithiasis and bladder cancer.

If you drink a little water, you will not only lose all these benefits but also get the opposite effect (deterioration).

We will talk about other signs of dehydration in a later paragraph.

Why children and the elderly may miss the thirst signals

Elderly people should be more careful about their fluid intake to avoid dehydration. Brenda Davey, a professor at Virginia Polytechnic Institute and State University, says the thirst mechanism becomes less sensitive after age 60.

Children, too, can have trouble replenishing fluids in a timely manner. Physician believes that children rarely follow the signals of thirst, so parents need to monitor their water consumption.

It will not be superfluous during the day, especially on a walk in hot weather, to offer the child water.

How to track dehydration: signs

If really concerned about hydration, you want to track it, there is a domestic way. It may not be the most pleasant: check the color of the urine. Normal urine is a pale straw color. A dark yellow or sandy color may show dehydration.

Of course, a dark color can signal a more serious problem than a lack of water in the body. Therefore, you should only check your water balance if you are healthy.

Symptoms of dehydration:

  • severe thirst;
  • dry and rough lips;
  • headache or dizziness;
  • rapid fatigue;
  • infrequent urination;
  • weak pulse;
  • low blood pressure.

Does the temperature of the water matter?

Many people are likely to have heard that cold water can help in losing weight. Well, there is little to no result in this direction from drinking cold liquids.

A doctor at the University of Southern California has proven that by warming cold water in the stomach, the body loses almost no calories. The negligible number of calories that are lost during this process affects nothing. The scientist’s name is Roger Clemens.

Cold water not only has no pluses, but it can be harmful:

1. Low-temperature water can harm tooth enamel.

2. It’s worse for satisfying thirst than warm water.

3. It can cause digestive problems after a greasy meal.

4. Cold water in the heat can cause the exacerbation of cardiovascular disease and weaken the immune system.

Should one drink water on an empty stomach in the morning?

Is it useful to drink one (or two) glasses of water on an empty stomach? Yes, it is.

The Japanese have a healthy habit: drink a glass of water in the morning on an empty stomach. This is probably one of the many factors that make the Japanese top the list of long-livers.

Drinking water on an empty stomach helps us wake up and starts the metabolic processes in the body. It cleanses the body of toxins, promotes weight loss, and improves the immune system, providing protection against infections.

The main thing:

1. Drink lukewarm water at room temperature.

2. After drinking a glass of water, you should be patient and not eat for 20-40 minutes. During this time, the water manifests its healing properties. By eating, you can prevent this.

3. Drink a glass of water as soon as you wake up. More precisely: wake up, brush your teeth and drink water.

4. It must be plain water, no juices.

5. And, of course, do not forget to drink water during the day.

Drinking a glass of water on an empty stomach is easy, but what a significant effect this useful habit has! Soon, you will notice an improvement in your body.

You may be interested: water with lemon on an empty stomach is a brilliant combination to start a productive day.

What kind of water to drink: boiled, filtered or bottled

Boiled water

This is the most economical way to satisfy your thirst. During boiling, germs die, chlorine evaporates, and excess salts settle to the bottom of the kettle, breaking it every six months (if you’re talking about an electric kettle).

But if the water is already low in salts, boiling is not the best source of clean water. Plus, boiling won’t handle chemical contamination (for example: heavy metals, nitrates or pesticides).

Bottled water

You can drink bottled water, because it must meet all the criteria of quality and safety, but not all manufacturers are conscientious.

But not every person or family can afford to spend a budget to buy bottled water. Therefore, people are thinking about buying a filter.

Filtered Water

Chemist and water expert Maria Kuleshova argue it is essential that the type of filter cartridge matches the type of water. For example, filters designed for tap water cannot purify spring water from bacteria. Such a function is not required because chlorine kills bacteria in tap water.

And also to drink clean water, do not forget to change the cartridge in time.

We can conclude that buying a filter looks preferable to spending the family budget on bottled water or constant boiling, which can not provide complete safety.

What you can’t quench your thirst with

It turns out that not all drinks help us cope with thirst, some even cause dehydration.

Coffee is not because, according to a study by British scientists, with moderate (only 4 cups a day) and regular consumption, coffee does not dehydrate the body.


Neither cold beer, nor any other alcoholic beverage, will help you quench your thirst.

Alcohol dehydrates the body, which is also helped by its diuretic property. That is why many people wake up with a hangover after a night out.

Sweet drinks

Do not believe television commercials, thinking that iced tea or sweet soda perfectly quench your thirst. Such drinks contain a huge amount of sugar, which not only harms our bodies but also prevents us from getting drunk.

The fact is that sugar penetrates into the body quickly and is absorbed, literally, in 5-10 minutes. After that, the concentration of sugar around the cells increases and water flows out of them.

As a result, a signal is sent to the brain that there is not enough water in the body and the water balance must be restored. Therefore, sweet drinks are drunk more willingly, but it is impossible to quench one’s thirst with them.

To sum up

A brief excerpt from the article
Most of the water in the body comes with food.
The amount of water you drink depends on your body.
Drinking too little or too much water has negative consequences.
Dark yellow urine may show dehydration.
Children and the elderly may skip thirsty signals.
It is best to drink water at room temperature.
Drinking a glass of water on an empty stomach is good for your body.
Filtered water is the golden mean between price and safety.
Alcohol and sweet drinks do not quench your thirst.


Now, to duplicate what was said at the beginning of the article, our body already has mechanisms built in that allow us to feel the approaching dehydration. So drink when you want to.

Every year, there are many studies and statements related to maintaining water balance in the body. Based on this, this article will be updated periodically.