喝牛奶竟比喝水解渴？ 炎炎夏日如何正确补水

喝牛奶竟比喝水解渴？

Well: Milk and Other Surprising Ways
to Stay Hydrated

Most people have heard that they should drink eight glasses of water a day to stay hydrated, but there is surprisingly little data to support this advice.
大多数人都曾听说日饮八杯水对补水的重要性。出人意料是，这个建议基本没有任何数据支持。
But now, a new “beverage hydration index” provides evidence-based suggestions for how to most efficiently hydrate.
但现在，新出台的“饮品补水指数”为高效补水的方式提供了有证据的建议。
The results showed that four beverages —
oral rehydration solution, like Pedialyte;
以电解质液体为代表的口服补水溶液fat-free milk；脱脂牛奶whole milk；全脂牛奶
and orange juice 橙汁
— had a significantly higher hydration index than water.研究显示有四种饮料的补水指数远高于水，它们分别是以电解质液体为代表的口服补水溶液；脱脂牛奶；全脂牛奶和橙汁。

Why is milk so efficient at rehydration?

牛奶高效补水的原理是什么？

“Normally when you drink, it signals the kidneys to get rid of the extra water by producing more urine,” Dr. Maughan said. “However, when beverages contain nutrients and electrolytes(电解质) like sodium(钠) and potassium（钾）, as milk does, the stomach empties more slowly with a less dramatic effect on the kidneys.”
“通常当你摄取水分时，肾脏会收到通过产生尿液来排出多余水分的指令，”莫恩博士说道，“但是若你饮用的液体含有营养成分和诸如钠和钾这样的电解质，比如饮用牛奶，那么胃的排空速率就会变慢，肾脏因此收到的指令变弱。”
Perhaps surprisingly, drinks containing moderate amounts of caffeine and alcohol or high levels of sugar had hydration indexes no different from water. In other words, coffee and beer are not dehydrating, despite common beliefs to the contrary, and regular soda can hydrate you just as well as water.
让人大感意外的是，含适量咖啡因、酒精或含糖高的饮料与普通水的补水指数相当。换句话来说，饮用咖啡和啤酒不易脱水，虽然这与人们的常识相左。同时，苏打水能和普通水一样带来同样的补水效果。

The hydration index could prove useful when making decisions about what beverages to consume and when.

补水指数对于决定何时饮用何种饮料或许大有用处。

For example, if you’re going on a long drive and won’t have access to fluids (or to bathrooms), you’d be smarter to drink milk with its high hydration index rather than water or iced coffee. But don’t forget that milk has many more calories than water, so don’t overdo it, either.
例如当你驾驶长途车，且有很长时间都不方便饮水（或是上厕所）时，饮用牛奶（补水指数高于水和冰咖啡）才是个明智之选。但别忘了牛奶比水含有更多的卡路里，喝奶虽好，可不要贪杯噢。
Dr. Armstrong noted that in hot weather, it’s important to monitor your hydration status throughout the day. He suggested paying attention to your thirst, and drinking when necessary. Also, if your urine color is a dark yellow, it’s time for a refreshing drink.
莫恩博士指出，在高温天气下，人们非常有必要全天注意体内的含水状况。他建议人们多注意自身的口渴状况，必要时补充水分。此外，若是你的尿液已经呈现深黄色，是时候补充水分了。 

本文为节选，来源：China Daily

点击“阅读原文”