The old eight glasses a day adage doesn’t add up.
Hydration sometimes takes a backseat to other health goals or priorities. Yes, there’s likely more instant gratification in taking the stairs instead of the elevator, but drinking enough water is a great goal. Here’s everything you need to know to answer the question “how much water should you drink a day” and easily stay hydrated.
Why is water good for you?
Doctors and dietitians always talk about the importance of hydration—and the hype is real. The cells, tissues, and organs of your body need water to function and carry out basic processes. “Water is a part of every bodily fluid, and plays many vital roles which include transporting nutrients, helping to remove waste, cushioning organs, lubricating joints, and moistening tissues,” says Malina Malkani, MS, RDN, CDN, a media spokesperson for the Academy of Nutrition and Dietetics. Water is so important that the average human body only lasts about three to four days without it, Business Insider reports. That makes sense as water makes up more than 50 percent of a person’s body weight, adds Kris Sollid, RD, the senior director of nutrition communications for the International Food Information Council Foundation.
Hydration is more than just a basic necessity. According to Nesochi Okeke-Igbokwe, MD, a physician and health expert, proper hydration improves everything from cognition and mood to body weight, and it promotes high energy levels, too.
How much water should you drink a day?
There is no perfect calculation to determine how much water you should drink a day, Malkani says. There are too many contributing factors, such as altitude, climate, activity level, diet, and personal medical history. Someone with a history of kidney stones, for example, may need to drink more water to prevent future stone formation, Dr. Okeke-Igbokwe says. If you eat a high-fiber diet, your body needs more fluid to process the food.
So, if it’s not the proverbial eight glasses, how much water should you drink a day? Malkani says that eight glasses of water a day isn’t a hard, fast rule—but it does remind people to drink more water, which is something many people need to do. There’s also no scientific evidence behind the eight glasses of water suggestion.
On average, Sollid says 80 percent of our water intake comes from fluids. If you like having number goals for how much water you should drink a day, note that the daily recommended fluid intake for women is around 11 glasses of water and 13 glasses for men, according to Sollid. Plain water is ideal for hydration, but all fluids contribute to water intake. The other 20 percent of water intake comes from foods with a high water content like strawberries and watermelon, he says. That’s why there are 7 ways to stay hydrated—besides drinking water.
How can I tell if I’m drinking enough water?
An easy way to see if you are drinking enough water is to check your urine. “If you are only producing small amounts of urine infrequently and it’s dark in color, you need to drink more water,” Malkani says. “If your urine is clear or light yellow, plentiful, and frequent, it’s likely you are getting enough fluids.” Of course, if you have dry mouth or thirst, you should drink more water, too, Dr. Okeke-Igbokwe says. The answer to how much water should you drink a day changes depending on other situations—like being outdoors, doing physical labor, and exercising—that require more water intake than usual.
How can I drink enough water?
Worrying and wondering how much water should you drink a day won’t happen if you break up your water intake. Alyssa Pike, RD, manager of Nutrition Communications at IFIC, suggests drinking 18 ounces of water at 7:00 a.m., 12:00 p.m., 3:00 p.m., and 7:00 p.m. Don’t rely on your thirst to remember to drink water. “By the time you’re thirsty, you’re likely already dehydrated,” Malkani says. “And thirst isn’t always a reliable indicator of fluid needs, especially in children and the elderly.” You’ll have no excuse for not drinking enough water if you invest in a big jug that you won’t have to get up and refill throughout the day.