Your Best Self Blog

Busting the '8 Glasses a Day' Myth

BY: Susan Crandell

For years, experts urged us to down eight big glasses of water a day. Turns out, that’s just one of those health myths that everyone has heard and no one can prove.

Researchers at Dartmouth Medical School combed through mountains of data and found no evidence to back it up. (They suspect it may have stemmed from an early misunderstanding from national nutrition guidelines.) The new, surprising, conclusion they reached: For most sedentary people who work indoors, 8 glasses may be too many.

Still, water is at the top of the food chain for good health, says registered dietician Wendy Bazilian, who has a doctorate in public health and is the co-author of The SuperFoods Rx Diet. “It’s the most important nutrient we consume. You can survive weeks without food, but only days without water.”

Water plays a role in many bodily functions: delivering nutrients and removing wastes from cells, stabilising body temperature and keeping our skin healthy and glowing. It’s important for oral health as well: Lots of water helps to minimise the plaque that can cause cavities and bad breath.

So if eight 225-ml glasses isn’t the right amount, what is? A good rule of thumb, says Bazilian, is to take in 225 ml for every 9.1 kg you weigh. But it needn’t all be drunk. A National Academy of Sciences report noted that while 80 percent of your daily water should come from beverages for proper hydration; the rest can be from water-rich foods.

How can you be sure you’re getting enough water? Follow these four easy tips every day, recommends Bazilian:

• Eat a fruit or vegetable at every meal. Apples, grapes and tomatoes are excellent water-rich choices.
• Have soup or salad at least once a day.
• Aim for at least six 225-ml beverages. Her favoritess: water (plain or sparkling, flavoured with a slice of cucumber or a squeeze of lime), green tea, low-fat milk and low-sodium vegetable drinks.
• Keep the weather in mind. You’ll be thirstier on a hot day than a cool one.
• Drink for your sport. Physical activity can dehydrate. The Australian Institute of Sport (AIS) recommends beginning your sport in “fluid balance” by drinking regularly throughout the day leading up to training or competition. Then, just before exercising, consume 200 ml to 600 ml of fluid. During your session, “begin drinking early and continue to drink small amounts regularly”. The AIS recommends sports drinks or water as the best options.