我們該喝多少水

◎黃曉琴

天熱時要多喝水，感冒咳嗽時要多喝水，氣候干燥時要多喝水，上火時要多喝水。那么，我們一天到底要喝多少水呢？一項發表在國際學術期刊《科學》上的研究顯示，每個人需要攝入的水量是不同的，具體需水量取決于多種因素。

Track 11

A famous health tip says you’d better drink eight glasses of water (about two liters) a day. However, the results of a new study suggest that less is needed.

An international group led by scientists at the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences found that the average daily water intake of a man in his twenties should be 1.5 to 1.8 liters, while it should be 1.3 to 1.4 liters for a female in the same age group.

The researchers1)investigated5,604 participants from the ages of 8 days to 96 years and from more than 20 countries, using isotope-tracking methods. They have found that a man aged 20 to 35 consumes 4.2 liters of water each day, while a woman aged 30 to 60 consumes 3.3 liters, with the water requirements dropping as he or she ages.

Since the2)metabolismand water exchange on skin can provide 15 percent, while food and drinking contribute half each of the remaining 85 percent,people are thus suggested to drink less than 45 percent of the total daily3)turnover, according to the researchers.

1) investigatev.調查

2) metabolismn.新陳代謝

3) turnovern.周轉率；流動率

每天要喝8 杯水（約2 升）的健康小貼士廣為流傳，但一項新的研究顯示，每天8 杯水的飲水建議可能超過大多數人真正的需求量。

由中國科學院深圳先進技術研究院的科學家領導的一個國際小組發現，20 多歲男性的平均每日水分攝入量應為1.5～1.8 升，而同年齡組的女性則應為1.3～1.4 升。

研究人員使用同位素追蹤方法，對20 多個國家共計5604 名受試者進行了研究，樣本年齡覆蓋8 天大的嬰兒到96 歲的老人。他們發現，20～35 歲的男性每天消耗4.2 升水，而30～60 歲的女性每天消耗3.3 升水，隨著年齡的增長，人體對水的需求量會下降。

研究人員表示，因為人體代謝和體表水交換可提供其中的15%，其余85%的需水量來自食物和飲水，食物和飲水各半，因此建議人們每天飲用的水少于總需求量的45%。