How Much Water Do You Really Need to Drink?

by | Dec 12, 2022 | Nutrition

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New research contradicts popular belief that drinking eight glasses of water a day is an essential health habit.

It’s not a mistake to think your body needs water — in fact, more than half of it is water, including more than 70 percent of the brain and heart. But do you need a water bottle on hand at all times to stay healthy?

For many, it’s “common knowledge” that one should drink 8 cups of water a day. But a new study in the journal Science finds that, just as is the case in almost every other aspect of diet and metabolism, the need for water varies widely from person to person.

The researchers analyzed data that encompassed nearly 6,000 people in 26 countries, from 8 days to 96 years old. Some were sedentary, some were athletes or farmworkers. Participants in the study drank water with “tracers” that allowed the researchers to estimate how much of the water they consumed was used in metabolism and how much they passed.

They discovered some interesting things. People with more “fat free” mass need more water. Water needs are greatest between the ages of 20 and 30. Not surprisingly, people who live in warmer parts of the world and who are more physically active need more water to keep things in balance.

How do you know how water much you need? The science-based advice is refreshingly simple: you should drink if you’re thirsty and avoid sugary drinks to quench your thirst. Coffee and tea can make you urinate more often, but they are hydrating nonetheless. Foods such as fruits and vegetables are also water rich.

The eight glasses per day rule may have its origin in a 1945 guidance by the U.S. Food and Nutrition Board which recommended daily water intake of 64 ounces (8 cups) from all sources, misunderstood as advice to drink eight glasses of plain water.

There’s no reason to worry if you’ve been consuming water as a duty, whether you’re thirsty or not. “If you drink eight cups of water a day, you’ll be fine — you’re just going to be spending a lot more time in the bathroom,” one of the study’s co-authors told the Washington Post.

You can find out more in this article by eSavvyHealth.

Fundamentals of Health Alliance

Fundamentals of Health Alliance


The Fundamentals of Health Alliance works to publish useful and reliable information about nutrition and health. Their mission is to empower readers to be informed with honest, non-biased information about food, nutrition and the vital components of health.

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