(ORDO NEWS) — An international team of scientists has predicted our daily water needs depending on anthropometric, economic and environmental factors.
Water is the main component of the human body, it takes up 50 to 70 percent of our weight. Every cell, tissue and organ needs water to function properly.
In particular, it helps to maintain normal body temperature, protects sensitive tissues, preserves joints, reducing the risk of developing arthritis and arthrosis.
Even mild dehydration can lead to attention deficits, decreased ability to perceive and process information, headaches, increased fatigue, and mood swings.
Fluid is excreted from the body through sweat, urine, breath. In order for it to continue to function properly, it is necessary to replenish the “reserves” of water by consuming drinks and foods containing water: normally, about 20% of the daily fluid intake comes from food.
But how much water should the average healthy adult living in a temperate climate, for example, drink?
Previously, the National Academies of Sciences, Engineering and Medicine of the United States of America determined that men need approximately 3.7 liters of fluid (equivalent to 15.5 cups) daily, and 2.7 liters (11.5 cups) for women – this is not only about clean water, but also other drinks and food.
In addition, we have all heard the recommendation to drink two liters of clean water per day, that is, eight glasses of water. Is this opinion correct?
Scientists from the National Institute of Health and Nutrition in Osaka, Kyoto University of Advanced Sciences, the University of Tsukuba (Japan), the Chinese Academy of Sciences, the University of Aberdeen, Roehampton University (UK) and the University of British Columbia (Canada) used isotope labeling to find out what human need for water, taking into account climate, living conditions and individual characteristics. The results are described in an article for the journal Science.
The researchers assessed the water consumption of 5,604 people (3,729 women and 1,875 men) aged eight days to 96 years from 23 countries, whose information was contained in the International Atomic Energy Agency’s (IAEA) International Doubly Labeled Water Database.
Participants drank a glass of water in which some of the hydrogen atoms were replaced by deuterium, a stable isotope of hydrogen that is harmless to humans. The rate of its excretion showed the rate of water metabolism in the body.
The results showed that water metabolism is significantly associated with age, weight, body fat content, physical activity, pregnancy, professional sports, socioeconomic status and living environment characteristics (country, air temperature, humidity level, altitude). seas).
“People who lived in countries with a low human development index had a higher water exchange (5.2 liters per day for men and 3.8 liters per day for women. – Approx. ed.) than residents of countries with a high HDI (3.9 and 3.1 liters per day, respectively. – Ed.).
Based on this extensive data set, we propose equations for predicting human water metabolism depending on anthropometric, economic and environmental factors,” the scientists said.
Energy expenditure turned out to be the most important factor: one of the highest rates of water metabolism was found in men aged 20-35 – an average of 4.2 liters per day if they lived in a country with an average human development index.
However, with age, the figure decreased to 2.5 liters for 90-year-old men. Water exchange in women aged 20 to 40 years was estimated at about 3.3 liters, and by the age of 90, the figure dropped to 2.5 liters.
Athletes needed about a liter more than those who did not play sports: about 5.1 liters for men and 4.1 for women. In addition to them, a faster water exchange was among residents of countries with a hot and humid climate, as well as among pregnant and lactating women.
“The study showed that the common recommendation that we all should drink eight glasses of water – or about two liters a day (we are talking about water in its pure form, and not about what we get from food. – Note ed.), is probably too exaggerated for most people, ”said one of the authors of the work, Professor John Speakman from the University of Aberdeen.
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