The body is composed of 60% to 70% water, depending on the morphology. After oxygen, water is the most important element for life. This water is essential for all vital processes. Fluids occupy almost every space in our body, both inside cells and outside. The water :

• maintains the volume of blood and lymph;
• provides saliva for swallowing food;
• serves as a lubricant for the joints and eyes;
• maintains body temperature;
• allows chemical reactions in cells;
• allows the absorption and transport of ingested nutrients;
• allows neurological activity of the brain;
• ensures hydration of the skin;
• removes wastes from digestion and various metabolic processes.

In a temperate climate, an average person spends more than 2 liters body water per day. In fact, the body loses more than a liter per day of body water through urine, and the same amount through sweat, stools and breathing (as evidenced by the mist on a mirror placed near the mouth ).

The losses in water are more important:

• in hot weather;
• during physical activity;
• during breastfeeding;
• in case of illness.

Each person therefore has water needs that are specific to her, given her size, the climate in which she lives and her way of life.

To assess these needs, the Mayo Clinic¹, in the United States, offers three approaches which take into account the fact that our diet also provides water, especially with fruits and vegetables which, for many, are composed of more than 80% water. These measures serve as scales. They are not based on precise scientific data.

Replacing. Evaluate the amount of urine excreted per day (approximately one and a half liters in an adult) and add one liter of body water expended for metabolism (moderately active person). The loss is 2 and a half liters. As the feed supplies on average 20% of our water needs, there are 2 liters left to recover. It is found in broths, hot or cold drinks and, of course, in drinking water.

The eight glasses of water a day: a myth. Rather, it is eight glasses of water or other liquids: juices, broths, hot drinks, etc. Drinks other than water contribute to the total water intake. Each glass is the equivalent of one cup (8 oz), making a total of approximately 2 liters.

The nutritional recommendation. In the United States, the Institute of Medicine recommends men drink 3 liters of beverage daily and women 2,2 liters.

For her part, nutritionist Hélène Baribeau formulates her recommendations to her clients: “To someone who does not exercise, men and women, I suggest drinking six to eight cups of water, or 1,5, 2 to 2 liters. People who do not eat a lot of fruits and vegetables should consume XNUMX liters. As for people who do heavy sweat training, I say take an extra liter for an hour of exercise. “

“You shouldn’t rely on the thirst signal to decide to drink,” says Hélène Baribeau. When we are active, we have time to lose a lot ofwater before feeling thirsty. It is therefore necessary to make a habit of drinking throughout the day. “

Is it better not to drink during meals? Nothing is opposed to this in the scientific literature. According to Hélène Baribeau, the only constraint is that it can generate discomfort because of the volume in the stomach. The important thing is to drink enough. If a person likes to drink moderately while eating, they should not be deprived of it.

However, pregnant women who have problems with nausea and vomiting may reduce their discomfort by avoiding drinking just before meals, during or right after³.

According to the precepts of Chinese dietetics, drinking a cup of hot water after a meal helps digestion. Hélène Baribeau does not see the need for it. “If you need a digestion aid,” she says, “you add lemon to the water to increase the acidity. But water alone will have no effect. “

Even when we drink a lot ofwater, there is no danger of “diluting” the nutrients that have been ingested or excreting them. Although it is extremely rare in a healthy person, too much water can still cause a potentially dramatic blood problem. This is sometimes encountered during sporting events, among marathon runners or cyclists.

A very large intake of water, beyond the quantity necessary for biological functions, will not cause magical benefits, also recalls nutritionist Hélène Baribeau. “It will not improve the firmness or appearance of the skin, nor the health of the nails and hair,” she says.

Note that excessive thirst can be a sign of diabetes. Consult our special Diabetes section to learn more about this disease.

People with hypertension should avoid Mineral water, which contain high proportions of mineral salts, such as sodium. Those with kidney problems should also avoid consuming it. Indeed, drinking water concentrated in minerals imposes an increased strain on the kidneys. The mineral salt content is indicated on the label of bottled water. These are the main warnings noted in the specialized literature. This is also the opinion of Hélène Baribeau.

People with gastroesophageal reflux disease who want to drink mineral water should choose it still and not carbonated. It is better, for these people, to avoid any source of additional gas or air, explains Hélène Baribeau.

For the rest of the population, the nutritionist suggests drinking no more than half a liter of mineral water in the same day. THE’mineral water can, for example, advantageously replace a carbonated or alcoholic drink. At other times, it is better to choose plain water.

Among naturopaths who advocate the practice of fasting, most recommend thedistilled water because it is the purest. Indeed, distilled water is completely demineralized water. It is obtained by collecting the water vapor after boiling.

Nutritionist Hélène Baribeau does not share this point of view. “There is no advantage in depriving yourself of the mineral salts normally present in water. I rather suggest thespring water, or even thetap water if it is treated by carbon filter. “

La Dehydration is defined according to body weight. Water loss representing as little as 1% to 2% of body weight is already considered dehydration. Loss of up to 15% to 20% of body weight can cause death.

Dehydration can be acute, as after intense exercise, or rather chronic, as a result of insufficient and prolonged consumption of water or other beverages.

The best way to detect dehydration is to observe the urine color. In healthy people, it should be a very pale yellow.

The first signs dehydration:

• dark urine;
• dry mouth and throat;
• a lack of energy;
• dry skin;
• headache and dizziness;
• heat intolerance.

We can compare these symptoms to those of a plant that is not watered often enough: etiolation, yellowed leaves, shriveled ends.

At a more advanced stage:

• muscle weakness or cramps, due to an imbalance in the potassium and sodium balance in the muscles;
• difficulty swallowing;
• painful urination;
• confusion or delirium.