How Much Water Do We Really Need to Drink?

It's summertime and that little voice in your head is telling you:
It's hot out-I need to drink a LOT!
By the time I'm thirsty, it's too late and I'm already dehydrated!
I need to get my eight glasses today!
Coffee and tea are diuretics and don't count toward my liquid consumption!

Confusing? Sure is. Conventional wisdom vs. truth is sometimes a tough thing to conquer.

MORE: Tips for Staying Hydrated in the Heat

The plain truth-and something we all know-is that we all need water. It regulates the temperature of our body, lubricates and cushions our joints, protects our spinal cord and helps get rid of wastes through urination, perspiration and bowel movements. And some researchers have found that it might even help promote weight loss in overweight dieting women by speeding up metabolism-a real bonus! Skimp on fluids and you risk dehydration, which can lead to fatigue, headaches, impaired concentration and memory and mood problems. While mild dehydration can be treated with water, severe dehydration requires immediate medical attention.

MORE: Symptoms of dehydration from the Mayo Clinic

But what if you don't like water? Many people complain that it's tough for them to drink even one glass. There's good news on that front:

The Institute of Medicine recommends women get 91 ounces of total water (men need a bit more: 125 ounces), which is about three cups more than the conventional wisdom of eight glasses a day, but that water doesn't have to all be gulped from a water bottle or glass.

Many foods contain water; that water goes toward your daily requirement. High points go to foods like watermelon, iceberg lettuce and tomatoes; even things like roasted and skinless chicken breasts, bananas and cooked broccoli contain water. In fact, at least 20 percent of the water we need comes from the foods we eat. Even if they contain caffeine, coffee and tea will still hydrate you.

For most healthy people, thirst is a reliable indicator of when it's time to drink. The exceptions: If you do heavy exercising or other activity in the extreme heat or lose excess fluid through vomiting or diarrhea. Sports drinks might be valuable for certain people (if you are a heavy sweater or exercise heavily for more than 60 minutes), since they contain electrolytes, which are lost in sweat, as well as carbohydrates to help your body refuel. But beware: they also contain a lot of sugar and, hence, extra calories. (For the average person, they're usually not necessary.) Adults and children take in about 400 calories per day in the form of beverages other than water.

MORE: Heat Emergencies: Knowing the Symptoms and How to React

And now that we've established some liquid truths, here are some fun ways to perk up your water:
1. Freeze a slice of lemon or small chunk of watermelon in ice trays with water
and add to seltzer or plain water to infuse it with extra flavor.
2. Use herbs like mint, lemongrass or parsley to add aroma and a hint of green to your water, or float some cucumber slices in a pitcher of water, with a generous squeeze of fresh lime.
3. Infuse plain water with valuable antioxidants by adding some crushed
strawberries or blueberries.

Enjoy this special recipe from Brian Preston-Campbell, author of Cool Waters (reprinted with permission from The Harvard Common Press):

SWEET TART
This drink is subtly sweet, mildly tart and definitely refreshing. I try to use
fresh cranberries throughout the fall and winter when I make this recipe, but frozen berries work just fine the rest of the year.

Prep Time: 5 minutes Makes six 10-ounce servings

Ingredients:
½ cup fresh or frozen cranberries, plus more for garnish
1 large red delicious apple, cored and coarsely chopped
1 tablespoon freshly squeezed lemon juice
1 small pinch ground nutmeg 6 cups chilled still water

1. Place the cranberries, apple, lemon juice, nutmeg and 2 cups of the water in a blender. Blend on high speed until smooth, for about 1 minute. Strain through a fine-mesh sieve into a large pitcher.
2. Add the remaining water and stir gently. Garnish the glasses with a few additional whole cranberries (they float!).