If you ask the internet how much water you need to drink every day, you’ll get guidelines all over the map. Many Americans seem to think more water is better. Our water bottles are not only getting larger, they’re getting smarter, with models that track fluid intake to help sippers drink more.
“Water is essential, it’s true, but how much water each person needs to maintain optimal health and wellness varies,” says Ashlee Carnahan, MS, RD, a registered dietitian nutritionist at Henry Ford Health.
The Benefits Of Water
When you consider that approximately 60% of your body weight is water, it makes sense that we need sufficient fluid to survive and thrive. Water lubricates your joints and tissues, improves circulation and eliminates waste through perspiration, urination and bowel movements.
There’s even research linking optimal hydration to longevity. One study reported that people who remain hydrated develop fewer chronic diseases, including heart disease and lung disease, and live longer than their less hydrated counterparts.
“Without sufficient water, several of your body’s processes take a hit,” Carnahan says. Even mild dehydration can make you feel slow and wiped out.
Other signs of not drinking enough water include:
- Bright yellow urine
- Constipation
- Dizziness
- Headache
- Low energy levels
Achieving Optimal Hydration
Not everyone requires the same amount of fluid to stay hydrated. How much water you need depends on a variety of factors, including your age, health status, activity level and even where you live.
Once you know what your body’s needs are—how much water you lose through breath, perspiration and eliminating waste—you can boost or reduce your fluid intake.
According to the National Academies of Science, Engineering and Medicine, sufficient daily fluid intake for people in a mild climate region is:
- 3.7 liters (15.5 cups) for men
- 2.7 liters (11.5 cups) for women
These guidelines take into account that most people drink about 80% of their water and get the other 20% from water-rich foods like watermelon, grapes and tomatoes.
Who Needs To Drink More Water?
You may lose significant water through exercise, sweating because of environmental heat, or even time spent in a sauna or hot tub. If so, your water needs will be higher than someone who doesn’t exercise.
Water needs also depend on your age and overall health status—and they can change from day to day. We need more water as we grow older, since our ability to regulate fluid and detect thirst declines with age.
You may also require more water to achieve optimal hydration if you are:
- Clearing an infection like a urinary tract infection (UTI) or yeast infection
- Fighting a cold, flu or stomach bug
- Pregnant or breastfeeding
If you need to hydrate better, spread your sipping throughout the day. Drink water with and between meals as well as before, during and after exercise. “It’s best not to let yourself get thirsty—that’s a sign that you’re already becoming dehydrated,” says Carnahan. She suggests taking a sip of water every 10 minutes throughout the day.
Can You Overhydrate?
Overhydration is rare, particularly among healthy adults. But it is possible to drink too much water. Athletes who engage in extreme sports or endurance exercise may be especially vulnerable as they attempt to avoid dehydration during long training sessions and competitions.
If you drink too much water without the accompanying electrolytes (minerals such as sodium that help regulate fluid in your body), your kidneys may not be able to eliminate the excess. When that happens, your blood sodium level gets watered down, resulting in a life-threatening condition called hyponatremia.
“People who have kidney disease or who need to restrict their fluids because of a condition like heart disease or congestive heart failure are at the highest risk of overhydrating,” Carnahan says.
Wondering if you’re getting enough (or too much) water? Watch your urine, suggests Carnahan. If your urine is nearly clear or pale yellow, you’re well hydrated, she says. If you’d like a more scientific assessment, check in with your doctor or dietitian to help determine the right amount of water to drink for your unique circumstances.
Reviewed by Ashlee Carnahan, a registered dietitian nutritionist who sees patients at Henry Ford Hospital.
