We all need water for a healthy life, but how much?

June 8, 2018

During the summer—and even year-round—our bodies crave water. There's no way to live without it. But just how much do we really need every day to stay healthy?

The answer can get complicated.

"It's hard to find an exact amount because it's variable based on your age, where you live, whether it's hot and humid, or cold and dry. Are you male or female, more active or less active," said Ilyse Schapiro, a registered dietitian with nutrition counseling practices in New York and Connecticut.

Studies have shown that water keeps the mind and body healthy, transporting nutrients, removing waste, regulating body temperature and keeping the cells working.

Although the total amount varies by age, gender and body composition, our bodies are 55 percent to 78 percent water.

The Food and Nutrition Board at the federal Institute of Medicine offers an estimate on a healthy balance of water for adult men and women. It suggests men have about 3.7 liters daily. That's about 15, 8-ounce glasses. Women should have about 2.7 liters, or 11 glasses.

But isn't the only way to stay hydrated. Most people get about 20 percent of their water from food.

Dr. Michael Sayre, an emergency medicine doctor at Harborview Medical Center in Seattle, said most people can—and should—listen to their body and brain.

"Your brain regulates that really well," said Sayre, who teaches at the University of Washington. "In terms of preventing [conditions] like heat stroke, it's generally people who ignored the signals they were thirsty or couldn't respond to them because they were physically impaired, or they were in an environment where they didn't have access to water."

Dehydration can begin within just a few hours of heavy exercise or extreme heat. Often, it happens with little notice, and by the time a person responds to their thirst they already are behind on a healthy water balance. Fatigue, headaches, dizziness, sleepiness and dry mouth can all be signs of dehydration.

"Don't let yourself get to that point of dehydration," Schapiro said. An obvious way to tell is the color of urine.

"We don't want to always talk about that, but it's a good indicator," she said. The clearer the color, the more hydrated a person is.

In many cases, medication and certain conditions such as diabetes or heart disease can impact how much water a person needs.

"A lot of and other types of medications tend to be diuretics," which cause the body to lose more water, Schapiro said. "In those cases, people should work with their doctor to make sure they are paying attention to hydration and keeping a healthy balance."

Sometimes, Schapiro said, people miss cues and mistake thirst for hunger. So, she counsels clients to keep a bottle of water at their side to drink from all day long.

"People forget to include in nutrition," she said. "People are busy and just not thinking about it. … If you are not well-hydrated during the day, you could be more likely to get a snack when you don't need it."

Explore further: Everything you need to know about exercise and hydration

4 shares

Related Stories

Everything you need to know about exercise and hydration

November 21, 2017
(HealthDay)—Working up a good sweat when you exercise lets you know you're working hard, but it's also a sign that you're losing water—water that needs to be replaced.

New research finds thirst is not the best indicator of hydration level

April 5, 2018
When it comes to staying hydrated, "just drink when you're thirsty" has been a rule of thumb for years. Yet a recent study by University of Arkansas researchers may prove that thirst alone is not a reliable indicator of proper ...

No one-size-fits-all for hydrating during sports

May 1, 2018
(HealthDay)—Waiting until you're thirsty to drink during sports could lead to dehydration and poorer performance, a new study finds.

Even mild dehydration can alter mood

July 12, 2016
Most people only think about drinking water when they are thirsty; but by then it may already be too late.

Drink up for exercise, but not too much

August 27, 2014
With students heading back to school, fall sports are in full swing. In addition to training, eating right, and getting enough sleep, a significant key to health and performance is staying hydrated. However, the recent tragic ...

Cranky today? Even mild dehydration can alter our moods

February 17, 2012
Most people only think about drinking water when they are thirsty; but by then it may already be too late.

Recommended for you

Living the high life: How altitude influences bone growth

June 19, 2018
High altitude is a particularly challenging environment—the terrain is physically challenging and the land has a relatively poor crop yield, so food can be sparse. Most importantly, oxygen levels are lower meaning that ...

Risks of cancer and mortality by average lifetime alcohol intake

June 19, 2018
The risk of mortality, and of developing a number of cancers, is lowest in light drinkers consuming an average of less than one drink per day across their lifetime, and the risk of some cancers increases with each additional ...

Bad habits that lead to cancer, chronic disease corrected by simple lifestyle intervention

June 19, 2018
Does this sound like someone you know? He or she spends too much time in front of screens, gets little exercise and eats a diet high in fat and low in fruits and vegetables.

Introduction of alcohol found to adversely impact fertility rates in hunter-gatherer community

June 19, 2018
Fernando Ramirez Rozzi, a research director with the French National Centre for Scientific Research has found that the introduction of alcohol to a Baka pygmy hunter-gatherer society caused fertility rates to fall. In his ...

Graphic warning labels linked to reduced sugary drink purchases

June 18, 2018
Warning labels that include photos linking sugary drink consumption with obesity, type 2 diabetes, and tooth decay, may reduce purchases of the drinks, according to a new study by researchers from Harvard T.H. Chan School ...

Greater levels of vitamin D associated with decreasing risk of breast cancer

June 15, 2018
Researchers at University of California San Diego School of Medicine suggest higher levels of vitamin D are associated with decreasing risk of breast cancer. Their epidemiological study is published in the June 15 online ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.