Most of us are chronically dehydrated, which saps energy and strains our moods. Follow four tips to make sure you get your daily fill. 
Credit: Illustration: Dante Terzigni

A lot of words are spent stressing the importance of proper nutrition: Eat a balanced diet; more plants, less meat; go easy on salt. But most of them focus on food. Just as important are the liquids you put in your body. Your system depends on adequate hydration to function. Proper hydration levels help keep your body at a safe temperature, lubricate joints for easy movement, remove waste from the body, and maintain a healthy metabolism. But many Americans are chronically dehydrated, even if at low levels, and don't know it.

"It's so easy to get to 1% to 2% dehydration. We're busy, we don't have water with us, and we're rushing around," says Douglas Casa, PhD, a kinesiology professor at the University of Connecticut. "That type of dehydration is very mild, almost imperceptible when it comes to feeling thirsty, but the things people would want functioning well for their general living—cognitive function, mood, and vigor—are negatively affected by that small amount of dehydration."

"So many of us walk around tired, weak, irritable, thinking that maybe we just didn't get enough sleep, which is possible, or maybe we're just in a bad mood. Really it could be subtle dehydration," says Bonnie Taub-Dix, RD, author of Read It Before You Eat It.

So how much water do you really need? Read on for tips to make sure your thirst is quenched at all times.

Smart Water Strategies

Do foods count toward my daily water goal?
Absolutely, and it's a great time of year to eat lots of hydrating foods. "Water is found in fruits and vegetables," says Kate Geagan, RD, author of Go Green Get Lean. "Watermelon is actually 93% water. Cantaloupe, tomatoes, and cucumbers are very hydrating." Soups and stews can be hydrating, as can yogurts and puddings. What about drinks other than water? They're mostly good. "Tea and coffee can hydrate your body," Geagan says. But beware the sips that stack up calories. Mindlessly sipping water all day is a good thing. Mindlessly sipping soda, juices, and sweetened teas or coffees, maybe not. "They all have calories, and if you're drinking them throughout the day, that really adds up," Geagan says.

Can I overhydrate?
Radio show gimmicks aside, it's extremely difficult to overhydrate to an unhealthy extent. "Somebody doing normal activity in their daily living doesn't really have the risk of overhydrating. Your kidneys are going to get rid of anything extra," Casa says. Still, because of the changes to mood, energy, and stamina when you're only 1% to 2% dehydrated, "don't be afraid to drink," he says. "It's better for people to be slightly overhydrated rather than slightly dehydrated." The only real drawback to drinking a bit more water: You may have to take a few more trips to the bathroom. But, hey, that means extra steps toward your daily goal.

Do I really need 8 glasses of water a day?
Maybe. "It has been debunked as some magic number for ultimate health, but it's still a good rule of thumb," Geagan says. "Women actually need about 9 cups a day; men, about 13. Still, as a guide, 8 is a great goal to shoot for." And if you work outside or exercise, drink more.

How can I ensure I'm hydrating properly?

  • Always carry a bottle of water. Have a glass next to you at your desk. Carry one in your bag. Keep one with you at the gym. Access to water will help you increase your intake. "When you're thirsty, it's already a little late," says Taub-Dix.
  • Have a glass of water with each meal. Before you pick up your fork, give yourself the reminder to go ahead and drink a glass. Geagan says studies suggest that people who drink a glass of water before a meal eat fewer calories, too.
  • Know your hydration status. Two things can give you a quick read on how hydrated you are: your urine and your urge to go. You should need to urinate about every three hours. And when you do, your urine should be light, similar to the color of lemonade, not dark like apple juice.