The Benefits of Water
Almost everyone knows that you should drink eight glasses of water a day. But
is it really necessary?
"Absolutely," says Cleveland Clinic nutritionist Andrea Dunn.
"Almost every cell in your body needs water to function properly. Many of
the patients I see don’t drink enough water. They aren’t dehydrated, but
they aren’t drinking as much water as they should -- especially considering
how much your body needs."
The human body, which is made up of between 55 and 75 percent water (lean
people have more water in their bodies because muscle holds more water than
fat), is in need of constant water replenishment.
Consider this: Your lungs expel between two and four cups of water each day
through normal breathing - even more on a cold day. If your feet sweat, there
goes another cup of water. If you make half a dozen trips to the bathroom during
the day, that's six cups of water. If you perspire, you expel about two cups of
water (which doesn’t include exercise-induced perspiration).
Ms. Dunn points out that a person would have to lose 10 percent of her body
weight in fluids to be considered dehydrated, but as little as two percent can
affect athletic performance, cause tiredness and dull critical thinking
abilities. Adequate water consumption can help lessen the chance of kidney
stones, keep joints lubricated, prevent and lessen the severity of colds and flu
and help prevent constipation.
"I encourage patients to drink eight to 10 cups of water each day. Those
who do report that they generally feel better," notes Ms. Dunn.
How do you know if you are drinking enough water? "A good test is to
look at your urine," points out Ms. Dunn. "If it’s clear or pale
yellow, you’re doing a good job of staying hydrated. But if it’s intense
yellow or gold, you probably need to drink more water."
But not everyone likes water. Many people prefer soft drinks, fruit juices,
sports drinks, coffee and other drinks. All these drinks can help quench your
body’s thirst for fluids, but they typically contain 100 calories or more per
"The best alternatives to water are diluted fruit juices, non-fat or
skim milk and diet soft drinks," explains Ms. Dunn. "But these drinks
shouldn’t supplant water. Take note of how much sugar is in these
alternatives. Sugar slows down the rate at which fluid is absorbed into the
body. If you have trouble drinking water because you don’t like the taste, try
adding a twist of lemon or lime or a splash of fruit juice. And cold water
Ms. Dunn notes that while bottled waters are very popular, tap water works
just as well and is more economical. It's also safe. The Environmental
Protection Agency (EPA) regulates tap water and requires that it be analyzed for
chemicals and bacteria. The Food and Drug Administration (FDA), which regulates
bottled water, doesn't require that it be analyzed for these substances.
In addition to water and other drinks, many foods are also good sources of
water. Juicy fruits like oranges, grapefruit, grapes, watermelon and apples can
help keep you healthy and hydrated. Carrots, tomatoes, tuna, yogurt, cottage
cheese, soups, rice and pasta also contain plenty of water.
"The key is to think and drink small amounts," suggests Dunn.
"The easiest way to stay hydrated is to drink a half-a-cup of water (four
ounces) each hour you’re awake. When you get in the car, take along something
to drink. When you sit down to watch TV, have something to drink. When you go to
a meeting, take along something to drink."
Copyright 1995-2005 The Cleveland Clinic Foundation. All rights reserved