By Cynthia Sass, MPH, RD
July 19, 2011
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Carbs, fat, protein and sugar always seem to be triggering some sort of debate, but good old water? It doesn't seem like it should be controversial at all, but it's been the source of some scuttlebutt recently after a health expert claimed that the need for eight glasses per day is "nonsense." So what's the deal? Here are five hard facts about agua.

TRUTH: Fluid needs aren't the same as water needs

According to the Institute of Medicine, women 19 and over need 2.7 liters of total fluid per day (about 11 8-oz cups) and men need 3.7 (about 15 8-oz cups). But that's total fluid, not just water, and foods can provide a significant chunk. For example an 8 ounce container of plain, nonfat yogurt supplies 7 oz of fluid, a cup of watermelon 5 oz and even a medium banana, which you don't think of as being "watery" provides 3 oz. Now that said, if you racked up 20 percent of your fluid needs from food that still leaves nearly nine cups of fluid to go for women, so if water is the only beverage you drink, eight cups (8 oz each) may not be enough.

TRUTH: We aren't drinking the right beverages

Studies tell us that most Americans drink about 2 liters of total beverages per day, but less than a quarter comes from water. Technically, non-water drinks like soda and lemonade do "count" toward your fluid needs, but of course, those drinks can also provide empty calories (calories that aren't bundled with valuable nutrients), sugar or maybe artificial stuff. So even if we're not all chronically dehydrated our beverage report card isn't earning high marks. In fact drinks are the No. 1 source of sugar in the American diet – eliminating just 1 (20 oz) bottle of soda per day would slash your sugar intake by 6,000 teaspoons a year. Bottom line: we'd probably all be much healthier if we reached for more water.

TRUTH: Coffee does "count" towards your fluid needs

Caffeine is a diuretic, which means it triggers water loss. However, newer research indicates that after about five days of consistent caffeine intake, our bodies adjust, and the caffeine is no longer dehydrating. Buy the key is to stick with "moderate" amounts (not a pot a day) and be consistent. In other words, if you typically start your day with a cup of Joe it can "count" toward your fluid needs, but if you usually stop at one and decide to go for a second one morning, or you're inconsistent, there may be a diuretic effect.

TRUTH: Drinking more water may help you lose weight

A recent study found that adults who simply gulped two cups of water before meals enjoyed a major weight loss benefit – they shed 40 percent more weight over a 12 week period while following a low cal plan identical to a second group of dieters. The same group of scientists previously found that subjects who drank two cups of water before meals naturally consumed 75-90 fewer calories, an amount that could really snowball day after day!

TRUTH: Plain water can be a little boring

I'll admit it – I'm not a huge fan myself. For flavor and added nutrients, toss in a few sprigs of fresh mint, sliced cucumber, wedges of lemon, lime or key lime, fresh grated ginger, or a splash of any type of 100 percent fruit juice. Or freeze juice and bits of whole fruit in ice cube trays and add them to your glass. If you need a little more sizzle go for seltzer or sparkling water – just be sure the only ingredients are carbonated water and natural flavors.


Cynthia Sass is a registered dietitian with master's degrees in both nutrition science and public health. Frequently seen on national TV she's a SHAPE contributing editor and nutrition consultant to the New York Rangers and Tampa Bay Rays. Her latest New York Times best seller is Cinch! Conquer Cravings, Drop Pounds and Lose Inches.