How Much Water Do You Really Need? (Video)

Have you noticed more friends or co-workers walking around with a bottle of water, determined to meet their quota for the day? The practice is becoming more common as more health-conscious people have adopted the age-old rule about drinking at least eight glasses of water a day.

But that old advice is mostly myth. Even dietitians don’t know much about its origin. To be precise, it refers to consuming eight glasses of eight ounces of water a day, or the “8 by 8 rule,” as the popular slice of wisdom goes.

But most healthy people can stay properly hydrated simply by following their thirst levels. The bottom line: There are several factors involved when figuring out how much water to drink each day, including a person’s weight, overall health and whether they spend a lot of time outdoors in a warm climate. Of course, working extensively outdoors, prolonged physical activity or exercising to stay healthy and maintain a proper weight requires additional fluid intake to prevent dehydration.

“Water is one of those topics that can be very controversial — how much you should have?” says Natalie Castro, chief wellness dietitian for Corporate Wellness at Baptist Health South Florida. “We used to have that recommendation of eight cups of water throughout the day, with each cup measuring eight ounces. That sounded really good, but there are so many factors that are involved.”

Video here

(Video: The Baptist Health South Florida News team hears from Natalie Castro, chief wellness dietitian for Corporate Wellness at Baptist Health, about proper hydration. Video by Dylan Kyle.)


Castro advises patients concerned about water intake to monitor changes in the number of times they have to go to the bathroom, and even the color of their urine, if necessary.  “If it’s (the urine) a pale yellow, that indicates a good hydration level,” she says. “If it has a very dark color, then that indicates dehydration.” (See chart at left)

There is no hard “8 by 8” rule for most people, but the most important factor for those who are overweight or have other health issues is to diminish the amount of sugary drinks, sodas or alcohol consumed in favor of water.

“If you’re currently drinking a lot of (high-sugar) sodas, juices or teas throughout the day, for example, you should try and replace at least one of those with plain water and then increase from there,” Castro says.

And when it comes to the “8 by 8” rule, Castro says you can use it as a goal to help you adopt healthier nutritional habits.

“How much do you need? It can be a little less than eight cups a day, or a littler more,” she says. “But you should be listening to your body to determine how much water you should be having or how thirsty you are.”

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With internationally renowned centers of excellence, 12 hospitals, more than 27,000 employees, 4,000 physicians and 200 outpatient centers, urgent care facilities and physician practices spanning across Miami-Dade, Monroe, Broward and Palm Beach counties, Baptist Health is an anchor institution of the South Florida communities we serve.

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