You’ve probably heard you’re supposed to drink at least eight 8-ounce glasses of water daily. But the classic advice is not the end-all-be-all of water intake. In fact, it’s pretty misleading.
“Fluid requirements vary among individuals based on age, sex, activity level, and even where you live,” Jessica Fishman Levinson, M.S., R.D., C.D.N., founder of nutrition counseling company. Your personal fluid requirements also can vary each day, depending on the other things you’re doing, eating, and drinking.
The Institute of Medicine recommends that women get 2.7 liters—that’s 11 cups—of water per day. Note, they don’t say you need to drink 11 cups of water a day. That includes all sources of water—from a basic glass of tap, to a cup of coffee, to the water content of the foods you eat.
All fluids count toward your daily intake, not just plain old H20.
According to the Mayo Clinic, the benchmark should really say “eight 8-ounce glasses of fluid,” not water, because drinking things like milk, tea, and juice contribute to your total. “Good options for hydration without added calories are waters infused with fruit and herbs, unsweetened tea, and sparkling water,” Levinson says.
So does the water you get from the foods you eat.
“Your body absorbs water in foods just like it would liquids,” Levinson says. Many fruits and vegetables have high water content. Some good options: watermelon (duh), cucumbers, lettuce, celery, tomatoes,strawberries, oranges, and grapefruit. Even soup, Jell-O, and ice pops count as fluid.
On the flip side, some foods and drinks can increase how much water you need.
“Foods with a diuretic effect, such as alcohol and asparagus, may cause you to excrete more water so you may need more,” Levinson says. If you eat high-sodium foods, your body likely will retain more water, leaving you thirstier. Drinking more fluids will help dilute your system and get fluids moving regularly again.
Since you’re not always keeping track of sources of fluids, the best way is by how your body feels.
If you’re thirsty, your body’s telling you that you need more water. “You might already be dehydrated,” Levinson says. Another good way to determine your fluid status is by taking a peek inside the toilet after you pee. “If your urine is light yellow, you’re probably getting enough fluids. If it’s dark or smells strongly, you probably need more water.”
Some of the signs of dehydration are fairly obvious—but others aren’t.
If you’re thirsty, you should drink. That’s a no-brainer. But did you know that hunger can also be a sign of thirst? Thirst and hunger cues come from the same part of the brain, so it’s easy to confuse the two. If you feel hungry even when you know you’ve eaten enough, there’s a good chance your body’s actually telling you it needs water, not food.
It’s also important to make a conscious effort to drink more whenever you’re getting sweaty.
Along with food, water is the fuel that powers your workouts. As you sweat, you’re literally losing water, and you have to replenish it as you go. Aim to drink one or two cups of water before you exercise, and sip about a half to one cup of water every 15 minutes while you’re working out. If you’re sweating really hard, or if you’re out in the heat, you might need more—listen to your body.