As we approach the new year, it’s only fitting that bettering ourselves and our wellness routines is top of mind. But that doesn’t mean that you have to join your local CrossFit gym or sign up to run a marathon. In fact, there are much smaller changes you can make to ease into living your best life. For instance, have you tried the cozy cardio trend yet? Or another relatively easy change you can commit to is simply drinking more water.
If you’re thinking, Sure, I could stand to drink a bit more water a day to get to eight glasses a day, we’re sorry to burst your bubble, but that’s not necessarily how much water should you drink each day. While there’s nothing inherently wrong with drinking eight glasses (or 64 ounces) of water a day—and that could be all that you need—it’s not an absolute amount that applies to everyone.
If you’re currently drinking eight glasses a day and feel that your thirst is satiated, you’re probably doing just fine. However, registered dietitian Erin Barnett, MS, RDN, points out that “this guideline is a simplified approach to hydration that overlooks factors that contribute to water intake.” And trust, there’s a lot more that goes into determining it than you might think.
Which raises the question: How much water should you drink a day? The answer is that multiple factors will influence what your own unique body and lifestyle require. Not to mention, drinking isn’t the only way to stay hydrated, since you can get water from food sources as well.
To set the record straight and figure out just how many times you should be filling up your Stanley cup each day, we spoke to Barnett and registered dietitian Laila Ouldibbat for their expert opinions. Read on to find out the daily water intake that’s right for you.
Approximate daily water intake—weight plays a role
Per the US National Academies of Sciences, Engineering, and Medicine, the general recommended amount of fluids a day is 15.5 cups (124 ounces) for men and about 11.5 cups (92 ounces) for women—much more than the widely believed 64 ounces. But of course, it’s not as straightforward as applying these numbers to everyone. Barnett explains that these numbers “were established for generally healthy individuals, taking into account age and gender only,” but these needs can fluctuate based on factors “including life stage, activity level, and overall health status.”
“Fluid needs can also be altered by an individual’s body mass and body composition,” says Ouldibbat, who points out that the Academy of Nutrition and Dietetics bases its recommendation on a person’s weight: “It recommends 30 to 35 milliliters of fluid a day for each kilogram that a healthy adult weighs. Therefore, for a 150-pound (68.2 kg) individual, fluid needs would be 70 to 80 ounces.” This calculation doesn’t separate out water intake from food, so if you’re eating lots of fruits and vegetables with a high water content, the amount of water you need to drink could be lower.
But, she explains, there are instances where weight-based recommendations may not apply, such as in cases of obesity, when it is crucial to use clinical judgment. The same applies to those on the other end of the spectrum. “If an individual is underweight or malnourished, a higher ‘ideal’ body weight may be used to accurately quantify fluid needs,” says Ouldibbat.
Another thing to pay attention to is how you feel. Obviously, if you’re thirsty, drink more water. But if it seems you need an excessive amount to quench your thirst, this could be an indication that something is up; a doctor or nutrition expert can help with specific questions.
Your water intake needs can change daily.
To complicate matters, and prove that there’s no hard and fast amount of water that you need each day, Ouldibbat says, “fluid intake goals can change daily based on your activity level, any losses such as sweating, and the season.” In short, the more you sweat—in which you lose water—the more water you’re going to need to drink. And often your body will tell you this without your having to think about it because you’ll naturally feel more thirsty.
How much you need to drink is also influence by age, health, and life stage. “Increased water intake is typically needed during pregnancy and breastfeeding,” says Bartlett. Ouldibbat points out, “Fluid needs will also increase as individuals approach geriatric age.” And Barlett says other reasons you may need to drink more water are if you’re sick (there's a reason doctors recommend drinking lots of fluids when you're under the weather), have certain health conditions, are taking certain medications, or are experiencing diarrhea.
What about other drinks like coffee, tea, soda, juice, etc.?
If you’re a Diet Coke fiend like I am (just one a day is a nice little treat, right?!), it actually counts toward your daily fluid goal. Caffeine does have a diuretic effect, increasing urination, but per the Mayo Clinic, most research has shown this effect is negligible. But caffeine is technically a drug, and limiting your intake is often the healthiest choice. And of course, sugary drinks have empty calories. Ultimately, Ouldibbat and Barnett stand by water being the best choice for staying hydrated.
How to tell if you’re dehydrated
In addition to the obvious sign of feeling thirsty, there are some other ways to tell whether you’re getting enough water. Ouldibbat recommends looking to your skin for certain indicators. “Pinch some of the skin on the top of your hand; if the skin immediately bounces back, you are likely hydrated.” Dehydrated skin, however, “will take a bit to return to normal. The more hydrated skin is, the more elastic it is,” she says.
Bartlett lists some other signs that can mean that you aren’t getting enough water: dark urine, reduced urination, dry mouth and/or skin, headaches, dizziness, or lightheadedness.
Strategies for incorporating more water into your day
Bartlett gives these easy-to-follow tips for upping your water intake:
- Drink some water first thing in the morning: Get in the habit of drinking a glass of water when you wake up.
- Invest in a fun, reusable water bottle: Look for one that can keep your water cold for 12 or more hours.
- Set reminders on your phone: Have them go off every hour or so.
- Have filled bottles everywhere: Keep bottles in places like your car, bedroom, and office, so you’re never without one.
