Cup of water on pink background

But you can still keep your emotional support water bottle.

You’ve probably been told to drink more water a million times, but a new study is pushing back against a common rule of thumb long held by healthcare professionals.

As it turns out, drinking eight 8-ounce glasses of water per day is far from a hard-and-fast rule, according to new research published in the journal Science. Scientists say there’s so many additional factors at play, and that every person is different in terms of what they need to stay hydrated.

“We have guidelines telling people how much water to drink,” said Herman Pontzer, a co-author of the study. “But the reality is that people have been kind of making it up.”

Understandably, this begs a lot of questions, so here’s a breakdown of where the myth originated and more details on how much water you really need.

Where did this advice originate?

This myth originally stemmed from a widely misinterpreted recommendation that was issued by the Food and Nutrition Board of the National Research Council in 1945. The council advised drinking a total of 64 ounces of water each day, but this intake was meant to also include all foods and beverages. Instead, people thought this meant that they should drink eight 8-ounce glasses of water every day, which wasn’t actually advised. But if you happen to already be drinking this much (or more), that’s completely fine, according to researchers — you just might be making more trips to the bathroom.

How much water do you need to stay hydrated?

The general guideline is to drink when you’re thirsty. And as you’ve no doubt heard, healthcare professionals recommend choosing water over sugary drinks like sodas because these can lead to metabolic problems like high blood sugar or increased blood pressure. But if you don’t really like drinking plain water, coffee and tea are good alternatives (contrary to popular belief, these beverages can be just as hydrating as water, as long as they contain 400 milligrams or less of caffeine per serving).

You can also get water from fluid-rich foods and meals like fruits, vegetables, soups, and sauces. Plus, Dr. Joel Topf told The New York Times that just the process of digesting food produces water, which can help add to your daily intake, too.

What other factors need to be taken into account?

Sex, size, physical activity levels, and climate all play a role in hydration. For instance, someone who has spent the whole day in the office with the air conditioner on blast might not need as much water as someone who just did an intense hike outdoors. You should also keep in mind that how much water you need could change over time. According to The Washington Post, water needs typically peak between the ages of 20 and 50. That said, older people in their 70s and 80s need to make more of a concerted effort to stay hydrated because they may not feel as thirsty.

You should also keep in mind that someone’s health history and personal diagnoses could impact hydration levels, and in some cases, feeling thirsty could be a sign that you’re already nearing dehydration. All that said, it’s important to consult your doctor about your individual needs.

Does the color of your pee really show how hydrated you are?

Despite popular belief, the color of your pee isn’t necessarily a reliable barometer of whether you’re staying sufficiently hydrated. Dr. Tamara Hew-Butler told The New York Times that even though dark yellow urine could sometimes signal dehydration, the issue isn’t so cut-and-dried, because there’s no solid science that backs this up.

After all, many things can impact urine color, such as diet. For example, Dr. Marie Spano told the wellness publication Well+Good that too much vitamin B, or eating certain foods like beets, can make your urine darker.

The bottom line

The good news is that most people tend to get enough water daily already, so dehydration isn’t necessarily something you have to worry about.

“If you’re paying attention to your body and drinking when you feel like you need to, then you should be fine,” Pontzer told The Washington Post.

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