We hate to break it to you, but chances are, you're not drinking enough water. Since childhood, we were advised to drink eight glasses of water—but most of us barely even meet that requirement, and we typically don't even realize how dehydrated we are until afternoon fatigue, headaches, or a major skin change kicks in. We all know the well-documented benefits staying properly hydrated include—assisting proper digestion, improving our complexion, and even revving up our metabolism. But if we told you that you may actually need more than the widely agreed upon "eight by eight rule" (drinking eight, eight-ounce glasses by 8 p.m.)? Don't take it from us, celebrity weight-loss coach Liz Josefsberg advises exceeding the current suggested amount. To fill us in, we tapped Josefsberg as well as internal medicine physician and nutrition specialist Dr. Amy Lee.
Meet the Expert
Keep scrolling to learn how much water you should be drinking for a healthy metabolism.
How Water Helps Boost Your Metabolism
"Hydration is one of the most important pieces of metabolism because your body is over 60 percent water and critical organs like the brain and heart are made up of even more," explains Josefsberg. "Being dehydrated puts a major strain on those important organs, depletes energy, erodes focus, and increases irritability." But here's where it the slopes become slippery. Each of those factors can be mistaken as hunger signals, and those who are dehydrated tend to reach for food instead of water. "Once I can get clients properly hydrated, we can begin really understanding true hunger signals and appetite seems to decrease without the added strain of dehydration," she says. "If you are looking for an almost immediate way to feel better and eat less, begin to properly hydrate."
Think about it like this: Drinking enough water is like giving more fuel to organs like the brain and heart. The result? Increased energy levels and a regular flushing of toxins and inflammation from the body. If you're looking to shed some pounds, staying hydrated will help you make better decisions and stop mistaking hunger for thirst. "To lose weight, use water to replace highly dense caloric liquid drinks," recommends Lee, who lists flavored coffee, sodas, and fruit juices among the usual suspects.
How Much Water Should You Drink Each Day?
The CDC currently recommends 2.7 liters of water a day for women. However, Josefsberg recommends exceeding that amount and aiming for 2.9 liters of water per day, despite your sex. Why? Our bodies can lose up to three to four liters a day just from daily activities like perspiration, urine, bowel movement, and exhalation of hair. But by making the target higher as Josefsberg suggests, you'll get closer to reaching the recommended amount.
Lee's suggestion is a bit less aggressive. "By simple rules, you should drink half of your body weight in ounces," she recommends. "If you weigh 150 pounds, you should drink 75 ounces. But, this is dependent on your level of activity and water loss in a day."
What Other Drinks Help You Stay Hydrated?
While water is the healthiest way to stay hydrated, there are other ways to meet your daily quota of water. Unsweetened teas and club soda are two alternatives Lee recommends. "Do not use diet sodas or drinks with artificial sweeteners," she warns, as these can cause food cravings for some. "Juices with natural sugars can cause you to want to drink more of the same fluid," she notes, explaining that the calories can add up. Josefsberg also emphasizes the importance of just plain water, but says other things like coffee, tea, or seltzer water can make up for some (less than one third) of daily water ounces.
How to Increase Your Water Intake
"Beginning the habit of drinking more water will not just happen because you want it to," explains Josefsberg. "Your habit is not drinking water throughout the day, so in order to trigger a new habit, you should use and set as many triggers for the new behavior as possible." She recommends using your smartphone to set three alarms throughout the day to remind you to drink up. "When those alarms go off, get up immediately from what you are doing a get a glass," she insists. "I encourage folks who work in an office atmosphere to get a water bottle that they begin to fill upon entering the building every morning and refilling at lunch."
For Lee, it's all about the visuals. "Have a water cup, drinking bottle, or mug available at home and at work next to you," she says. "Sometimes, you need a constant visual reminder to take the action of drinking water." And if you find water "boring," she says to drop in non-caloric powder, a few berries, or sliced up lemons, cucumber, or mint.
You'll know you had a good water intake day if you fill up and finish a 1L water bottle three times a day.
Can You Drink Too Much Water?
Lee and Josefsberg both agree that though it's a rare occurrence for most people, it's possible to drink too much water. "The amount of water that is considered too much is the amount that changes one's sodium level in the blood," says Lee. "Our bodies are smart enough to regulate water intake by increasing urinary output, but there are situations when your body cannot catch up due to the speed that you are drinking."
So, just how much is too much? While Lee suggests drinking three to four cups first thing in the morning before breakfast, "too much" can be a range of five to six liters in a short period of a few hours. The risk is most common among athletes, but Lee notes that there are "medical and psychological conditions that cause people to drink a lot due to loss of thirst receptors."
Cleveland Clinic. How much water do you need daily? Updated August 6, 2020.
Rosinger A, Herrick K. Daily water intake among U.S. men and women, 2009-2012 (NCHS Data Brief No 242). National Center for Health Statistics. April 2016.