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Healthy Living · article

Do we really need eight glasses of water a day?

Woman drinking water

Gone are the days of drinking water from a garden hose or public water fountain when we’re thirsty. Today, our insulated water tumblers are always within reach for hydration-on-demand, day and night. 

So, is constant water intake really necessary? And should everyone adhere to the same consumption guidelines? According to John Saldarini, MD, a nephrologist at Atlantic Health System, the answer is no.

A dependance on water bottles

“Staying hydrated is always a good idea, but the blanket recommendation to drink eight glasses of water every day is not supported by strong data or rigorous academic studies,” says Dr. Saldarini. “For most people, drinking this much water only increases the amount of urine they excrete.”

Dr. Saldarini explains that while it’s rare for healthy people to experience side effects from consuming too much water, the benefits of excess consumption tend to be exaggerated. Here are a few tips to guide your water intake.

  • Foods help hydrate your body.  Most of the foods you consume have high levels of water that contribute to your daily water requirement. For example, beef is about 50% water, and fruits and vegetables are 70 to 90% water.       
  • Your kidneys are workhorses. Kidneys are exceptional at conserving water while pulling out essential nutrients and electrolytes. If you are in good health, drinking more water doesn’t make your kidneys work better. In fact, excessive water intake can deplete your body of important electrolytes.
  • Salt helps you stay hydrated. That’s right, consuming a healthy amount of salt is as important as consuming water. Salt helps your kidneys maintain your internal fluid balance. It helps your body absorb and retain the proper amount of water to keep it functioning optimally—especially during physical activities and extremely hot weather.

The answer is in moderation

Dr. Saldarini cautions that when it comes to water—and salt—it's important not to overdo it. He says, “The ill effects of excessive salt intake are well recognized, while the health issues that develop from overhydration, although less well known, are equally real.”

He explains that when it comes to water consumption, your body knows best. And diet and nutrition are just as important as water consumption.

“Drink up if you’re thirsty. That’s your body telling you what it needs,” he says. “There’s nothing wrong with carrying around a water bottle. But forcing water into your system all day long is not a recipe for good health. To feel great, you might want to focus on a healthy meal along with that glass of water.”

Published: January 28, 2025

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Staying up to date on annual wellness exams and screenings is important. So too, are the occasional trips to specialists to address sleep issues or any other health concerns that are nagging you.

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