The advice to drink eight glasses of water per day to stay healthy could be misleading, a new study has found.
The research looked at data from 5,600 people across 26 countries with ages ranging from seven days old to 96 years old. It found that people may need less than this amount per day, but requirements can vary on an individual basis.
“The science has never supported the old eight glasses thing as an appropriate guideline, mainly because it confused total water turnover* with water from drinks. And a lot of your water comes from the food you eat,” says lead author of the study, Professor Dale Schoeller. “This study is the best we’ve done so far to measure how much water people actually consume on a daily basis, and the major factors that drive water turnover.”
Results show daily water needs peak among men aged 20-29, but they remain the same for women from the age of 20 to 55. The team also found that men’s and women’s water requirements differ by about two glasses, or half a liter. The average 20-year-old man of normal weight living in a temperate climate would take in and lose about 3.2 liters every day. For women, that number is closer to 2.7.
According to the study, physical activity level explained the largest proportion of the differences in water turnover, followed by sex, the Human Development Index (人类发展指数), and age. The researchers found hunter-gatherers and farmers in developing nations had higher water turnover than those in industrialized economies. In other words, the lower your home country’s Human Development Index, the more water you go through in a day.
“That’s representing the combination of several factors,” Schoeller continues. “Those people in low HDI countries are more likely to live in areas with higher average temperatures, and more likely to be performing physical labor. That, plus being less likely to have access to a sip of clean water whenever they need it, makes their water turnover higher.”
The results of the study will have an influence on global warming. The researchers hope that the study will be able to help to predict more specific and accurate future water needs.
* water turnover:
水周转量，即水的总交换量，包括了我们摄入的水分和流失的水分。
【小题1】What can be learned from the new study?
| A．Women need less water per day when turning twenty. |
| B．Men consume the most water per day in their 20s. |
| C．Men consume two liters of water per day more than women. |
| D．The daily water turnover of a man doubles that of a woman. |
| A．Approved. | B．Objective. |
| C．Negative. | D．Unclear. |
a. Gender difference.
b. Water drinking habits.
c. The amount of physical work a person performs.
d. The level of development of the country a person lives in.
| A．acd | B．bcd |
| C．abd | D．abc |
| A．The water shortage problem faced by low HDI countries. |
| B．The poor living condition of people in low HDI countries. |
| C．Why people living in low HDI countries have higher water turnover. |
| D．Why people living in low HDI countries cannot get clean water. |
