Dehydration

Preventing dehydration. (a healthy adult should
drink 8 to 10 cups of water per day)

Author/s: Lee Reilly
Issue: Jan, 1998

Q How easy is it to get dehydrated? And what are the symptoms? I drink water when I'm exercising, but the rest of the time I depend mostly on coffee, tea and diet sodas. My sister keeps warning me that I'm going to get sick. Is she right?

Modern life is like a marathon: sustained activity punctuated by opportunities to drink water. Unfortunately, in America, we tend to forego those opportunities more than we should, and a lot of us walk around in a state of mild dehydration. If you're the type to take a two-hour plane flight, drink a cup of coffee on the way, and head to a meeting in an airtight high-rise, by the time the work day's over, you will have lost as much as 1 percent of your body weight. This fluid loss is significant enough to affect your body's internal thermostat. "The plane ride alone could do it," notes Ann Grand-jean, Ed.D., director of the International Center for Sports Nutrition, a nonprofit education and research institute located in Omaha, Neb. "That recycled air is very dry."

Water is our essence, our very lifeblood, the most important nutrient in our body. It makes up 70 percent of our muscles and 75 percent of our brains; oxygen is the only thing the body craves more than water. Yet every time we exhale, we lose it--as much as two cups a day. Water evaporates invisibly from the surface of our skin too--an additional two cups a day; and each time we urinate, we lose even more--probably as much as 2 1/2 pints in a 24-hour period. During the course of a regular day, a healthy adult can lose eight to 10 cups of water--and that's before shoveling snow off the sidewalk or working out at the gym.

When we fail to replenish the losses, we set up a physiological chain reaction. Reading a "water shortage" message, hormones tell the kidneys to conserve water by urinating less; the urine passed is amber-colored (healthy water intake produces light-tinted urine). Along with contributing to constipation and bloat, dehydration trips up other body systems: At a 3 percent loss of body weight, muscular endurance diminishes; at 4 percent, dizziness occurs, and physical labor capacity declines by as much as 30 percent; at 5 percent, you'll experience problems with concentration, drowsiness, impatience and headache; at 6 percent, the heart is racing, and the body's temperature regulation system starts to fail (athletes may notice that they've stopped sweating); at 7 percent, there's a good chance of collapse.

To prevent dehydration, experts recommend that everyone drink six to eight glasses of water a day. But even Grandjean admits that determining water intake is not an exact science. "There are variations in individual needs and variations in diets." For instance, she points out that the recommended drinking water quotient takes into account the 3 to 4 cups of water typically consumed through foods (fruits and vegetables are about 80 percent water; bread is one-third water), but not everyone gets this amount.

So the eight-glasses-a-day rule is essential--and that means water--and not most other fluids. If you regularly fill your tank with coffee or cola, keep in mind that a mere two-thirds of a caffeinated drink counts toward your daily water intake--just 8 ounces of that 12-ounce diet soda. And alcohol actually depletes water reserves. It takes 8 ounces of water to make up for drinking 1.5 ounces of alcohol. Instead of ordering another glass of wine, consider seltzer; it's as good as water. And thankfully, 90 percent of your morning class of orange juice or milk counts toward your quotient.

"Eight glasses is doable," confirms fill Nussinow, R.D., a vegetarian cooking instructor in Santa Rosa, Calif., "The best way to make it doable is to make it available." She suggests keeping bottled water on your desk at the office. At home, try jazzing up tap water with a slice of lemon or other types of fruit, then drinking a glass with meals and snacks. And absolutely everyone should drink before, during and after exercise. Think of drinking as akin to breathing, and water as the purest, most replenishing oxygenated air--a critical element of life itself.

Lee Reilly is a frequent contributor to Vegetarian Times.

Prevention of Dehydration