A formula that can accurately predict the amount of water lost from the human body per day is found

Part of the human body is made up of water. Studies have shown that the ratio (body water content) is about 60% for infants, about 53% for general men, and about 45% for general women. I didn't know the exact number of the lost. Recently, researchers at the National Institutes of Biomedical Innovation, Health and Nutrition have derived a formula that accurately predicts how much water flows in and out of the human body (water turnover). I was.

Variation in human water turnover associated with environmental and lifestyle factors | Science


Invented the world's first formula to predict the amount of water turnover in the human body-From the results of an international joint survey of 5604 people in 23 countries- | National Institutes of Biomedical Innovation, Health and Nutrition


Predicting water turnover in the human body – Waseda University

Research is conducted by Yosuke Yamada, Director of the Exercise Guidelines Laboratory , Physical Activity Research Department , National Institute of Biomedical Innovation, Health and Nutrition (NIBIOHN) , Waseda University, Kyoto University of Advanced Science, University of Tsukuba, and China, the United Kingdom, the United States, and Canada. This was done jointly by researchers from research institutes such as

The research team focused on the change in the stable isotope value of water (H2) in the body, which increased slightly due to drinking water and then returned to the original value within a few months. By using a stable isotope ratio mass spectrometer that can accurately capture the amount of change, we devised a method to measure body water content and water turnover rate. A total of 5,604 men and women, including the elderly, were measured.

As a result, it was found that infants lose about 25% of their body water on average, and adults lose about 10% of their body water each day. Below is a graph of the average water turnover rate for each age, showing that the older the age, the lower the water turnover rate. There was little difference by gender. However, this is only an average value, and when comparing individual values, some people have a daily water turnover rate of only 5%, while others have as much as 20%.

In terms of volume, the highest water turnover is for men between the ages of 20 and 35, averaging 4.2 liters per day. By the time you're in your 90s, it drops to an average of 2.5 liters per day. In the case of women, the value was high between the ages of 30 and 60, with an average of 3.3 liters per day, and decreased to an average of 2.5 liters per day in the 90s, similar to that of men.

In addition, water turnover showed high values when the temperature was high or when living near the equator, and when living in extremely cold places or in the Arctic Circle, it was also high. . In addition, water turnover was higher on average in hot summer than in spring, and water turnover also increased in late pregnancy as the fetus grew and body water content increased. In addition, developing countries, countries with a lot of manual labor, people with a lot of physical activity on a daily basis, and athletes also had higher water turnover values.

The following is derived as a formula that clarifies the influence of these factors.

Water turnover (ml/day) = [1076 x physical activity level] + [14.34 x body weight (kg)] + [374.9 x sex] + [5.823 x average daily humidity (%)] + [1070 x athlete ] + [104.6 x Human Development Index (HDI)] + [0.4726 x altitude (m)] - [0.3529 x age squared] + [24.78 x age (years old)] + [1.865 x average temperature squared] - [19.66 ×Average temperature (°C)]-713.1
・Physical activity level: 1.5 for sedentary, 1.75 for average, 2.0 for high
・Gender: 0 female, 1 male
・ Athletes: 0 non-athletes, 1 athlete
・HDI: 0 developed countries, 1 intermediate country, 2 developing countries

Note that just because men aged 20 to 35 lose an average of 4.2 liters of water a day, it doesn't mean they should drink 4.2 liters of water a day. . This is because there is water that enters the body from the water produced in the body's energy metabolism and exhalation, and the food itself contains water. If you are ingesting, you are ingesting about 1.8 liters of water, so the amount you need to rehydrate as a liquid is about 1.8 liters. In the case of women in their 20s, it will be about 1.4 liters.

Further research is needed on the relationship with the risk of disease and mortality.


A site that can easily and accurately calculate the amount of water lost from the human body per day appears - GIGAZINE

in Science, Posted by logc_nt