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Health Experts Debate How Much Water We Should Drink Daily

MINNEAPOLIS (WCCO) -- For the last month, we've seen a new debate over just how much water we should be drinking each day.

It started in July, when medical researchers at Harvard University published an article stating there is no scientific evidence that we need to drink eight glasses of water a day. After that, other health experts weighed in an echoed a similar message.

We spoke with dietitian on Tuesday to find out why what was considered a "well-known fact," is now being questioned. It appears something important was left out of the equation when it comes to how many glasses of water we should drink each day.

That something would be the foods we eat that contain water, and the other drinks we consume that help hydrate the body. You've probably heard it since you were a child: Be sure to drink at least eight glasses of water a day.

Well, you may be hearing less of that in the future. Brenna Thompson is a registered dietitian at Nutritional Weight and Wellness.

"Ultimately it comes down to the fact that everyone is an individual. Someone who is older and very sedentary is going to need a lot less water than some of my clients who are younger and doing triathlons, and you've got everyone else in between," Thompson said.

The article published in the Harvard Health Letter in July recommends drinking about four to six glasses of water a day. That's enough because certain foods, like fruits and vegetables, count towards your daily water intake.

"Ultimately, if we are eating lots of those during the day then that can aid in us staying more hydrated," she said.

Brenna says it's very important to drink water every day because it enables your body to function efficiently, flushing out bacteria and preventing dehydration.

"The effects that people feel immediately when they start drinking more water, staying hydrated in general, is that they notice they have more regular bowel movements, they may not have that afternoon headache any more, just more energy, better brain function," she said.

Other liquids we drink help hydrate us as well, but beware of those sugary drinks like pop and fruit juices.

"Let's keep reminding people to drink water, to stay hydrated, but to get into a huge debate over exactly how much we need seem futile, because again, everybody is different," she said.

So, what's the source of the belief that eight glasses of water a day is what's needed?

The New York Times references a recommendation made in 1945, by the Food and Nutrition Board. Apparently what got lost in that announcement was a sentence that stated, most of the recommended quantity of water is contained in foods.

Yes, in general, but as you heard that dietitian say it really depends on the individual. If you are eating a healthy amount of fruits and vegetables each day, or drinking tea or juice, eating soups, you are adding to your daily water intake so that four to six glasses is fine.

But folks who actively exercise or do physical labor, or eat poorly, probably need more.

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