Water seems to have 8 rules. Popular and oft-repeated advice says he drinks eight 8 ounce glasses per day for good health.
But is it really so? Here’s what you need to know about how much water you really need.
What are the health benefits of water?
“There is a fairly long list of reasons why maintaining proper hydration status is important to keep someone healthy.
A registered dietitian, Davey studies how water and beverage intake affect health. Adequate hydration is associated with good cognitive function, optimal energy levels, weight management, and a reduced risk of urinary tract infections and kidney stones, she says.
According to the Centers for Disease Control and Prevention, water also helps regulate body temperature, lubricate joints, and remove waste products through urine, sweating, and bowel movements.
According to a National Institutes of Health study published in 2023, adults who don’t drink enough water are more likely to die younger, as measured by higher levels of sodium in their blood.
“These results suggest that adequate hydration may slow aging and prolong disease-free living,” said study author and researcher at the National Heart, Lung, and Blood Institute. One Natalia Dmitrieva said in a statement.
But research doesn’t prove drinking more water prevents chronic disease, experts told NBC News. Lawrence, director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins University Dr. Appel says the relationship between drinking water and age-related chronic diseases remains “highly speculative.”
What is the recommended amount of water intake?
There are no recommendations from the CDC on how much plain water anyone should drink each day. However, for his total daily fluid intake from various beverages and foods, the agency consults the recommendations of the National Academy of Medicine.
It recommends that women drink 9 watery drinks a day and men 13 watery drinks.
These recommendations take into account that you get about 20% to 30% of your daily water needs from foods such as fruits and vegetables.
There are some studies back in the 1930s and 1940s that support the rule of drinking eight 8-ounce glasses a day, but that’s just a “rough guideline,” Davy says.
But a 2022 study published in Science raises questions about whether people need to drink that much water.
“Most people will find that they don’t need eight cups a day,” study co-author Herman Ponzer, a professor of evolutionary anthropology at Duke University, tells TODAY.com.
“Our research shows that ‘one size fits most’ doesn’t work for hydration. A person should listen to his body and drink when he is thirsty. In general, larger people need more water. Athletes and people in physically demanding jobs need more water, as do people in hot environments.”
You may also need to drink more if you have a fever, or if you have diarrhea or vomiting.
There’s no harm if you want to drink eight glasses of water a day, but there’s no obvious benefit either.
Does it have to be water?
Hydration doesn’t have to mean just water, but “many people recommend water as the ideal drink for hydration because it contains no calories,” Davey says.
Beverages such as unsweetened coffee and tea are also good ways to maintain adequate fluid intake. Studies show that drinking moderate amounts of coffee daily (3-6 cups per day) does not dehydrate you.
Can you rely on thirst to know if you’re drinking enough fluids?
Our natural thirst-sensing mechanisms may be functional enough to avoid more severe dehydration, but may not be sensitive enough to avoid mild dehydration.
Studies show that it’s common for adults to fall 1% to 2% below optimal hydration levels, which can affect cognitive function and lead to brain fog, she adds.
It can become a particular problem later in life. Older people are more prone to dehydration than younger people, says Davey, because our thirst mechanisms decline with age.
Besides being thirsty, how does the body signal dehydration?
Check urine color. Usual shades are usually straw or light lemonade. The darker the color, the more you need to drink. This is a very simple and practical method, but be aware that some vitamins and supplements can affect urine color.
Also, try the pinch test. Squeeze and release the skin on one knuckle for about 3 seconds.
With sufficient moisture, the skin will snap back into place within seconds. However, when it lacks moisture, the skin loses its elasticity and becomes pinched for a while.
Is it better to drink tap water or bottled water?
“I like to promote tap water as the ideal water source because it is accessible, affordable and safe for most people,” says Davy.
“Tap water also has the advantage of being fluoridated in most areas, which is important for dental health.”
How does water intake affect weight?
Davy and her colleagues conducted a study showing that drinking about two cups of water before meals may help middle-aged and older people manage their weight.
It may help promote satiety, so people can eat less and drink less calorie-containing beverages.
This story first appeared on TODAY.com. More from today: