David L. Katz, MD
Q: I don't like plain water. How much do I really need?
— Nancy Sawyer, Dacula, Georgia

A: Staying well hydrated is important for good blood flow, weight control, healthy kidneys and skin—just to provide the short list. But getting enough fluids is nowhere near as hard as we've been led to believe. The eight-8-ounce-glasses-a-day rule isn't based on science and is about as precise as saying everyone needs 2,000 calories daily.

For the average person on a temperate day, the body loses roughly 10 cups of fluid. The typical diet provides about four cups of water from food alone. If you eat healthfully, you're probably getting more than the average, thanks to fresh fruits and vegetables. One navel orange, for example, contains roughly half a cup (four ounces) of water. As for the rest of your water intake, any liquid you drink—juice, milk, soda, tea, coffee—counts toward your daily total. (Caffeine is a diuretic but doesn't negate the hydration benefit.) Research has found that thirst is an excellent indicator of when to drink, so keep beverages handy, drink when you're thirsty, and you should be fine.

For alternatives to plain water, Polar Beverages (polarbev.com) makes flavored seltzers that have no calories, no sodium, and no artificial sweeteners. You can always mix your own by putting a splash of fruit juice or a wedge of lime in a glass of carbonated or sparkling water. You should be able to keep your palate happy and stay well hydrated.