Do you need to drink more water every day? The answer might be more complicated than you think.
“There’s probably not a one-size-fits-all recommendation for how much water someone should drink, especially given the fact that we’re all shaped differently, have different kind of exercise routines, and live in different climates,” said Benjamin Breyer, MD, chair and professor of urology at the University of California – San Francisco.
In a new study review, Breyer’s team summarized 24 years of recent scientific evidence on increasing water intake. Multiple studies found that drinking more water could boost weight loss (by 44% to 100%) and reduce kidney stone risk (15 fewer events per 100 participants over five years). Boosting hydration could also help prevent migraines, aid blood sugar control, and reduce the risk of urinary tract infections and hypotension – dangerously low blood pressure. However, the quality and quantity of research was limited.
Here’s what we know so far about the benefits of drinking more water – and how to see whether you are getting enough.
How Much Do You Need?
Eight glasses a day is a popular guideline for water consumption, but is it enough?
“Eight glasses per day is not the best recommendation for everyone,” said Stavros Kavouras, PhD, founding director of the Hydration Science Lab at Arizona State University. Think of eight 8-ounce glasses as the bare minimum, not the target.
For optimal hydration, a better guideline is the National Academy of Medicine’s hydration recommendations (about 13 8-ounce cups of fluid for men and nine 8-ounce cups of fluid for women per day). Men also need 3 cups and women need 2 cups of water from food like fruits and vegetables each day.
The Benefits of Drinking More Water
The research team found that upping your H2O intake could improve health in the following ways:
- Weight loss. People who drank 500 milliliters of water (about 17 ounces) before each of their three daily meals lost 44% to 100% more weight than people in control groups. A 17-ounce drink of water “can fill up your stomach and maybe be a natural appetite suppressant,” Breyer said. However, when people drank more water throughout the day, and not just before meals, there was no weight loss benefit.
- Kidney stones. People who increased their water intake had a lower risk of kidney stones and went an average of 13.6 months longer between kidney stones than people in the control group. By drinking more, you might reduce the concentration of stone-forming salts in your pee, the researchers say.
- Blood sugar. When people with type 2 diabetes drank extra water, their fasting blood sugar levels decreased. One theory is that by drinking more water, you can increase your blood volume and dilute the glucose concentration. However, in a study of people with normal blood sugar levels, drinking more water was linked with a slight increase in blood sugar, though not to harmful levels.
- Headaches. One study found that increasing water intake by 1,500 milliliters (about 51 ounces) per day helped people with migraine headaches feel slightly better. Another study showed no effect on headaches.
- Urinary tract infections. When women with recurrent UTIs who drank less than 1,500 milliliters (about 51 ounces) per day were asked to double that amount, they had an average of 1.5 fewer UTIs over the next 12 months. They also went longer between UTIs and required fewer rounds of antibiotics to treat them. By staying well hydrated, you might dilute bacteria in your urine and pee them out before they can multiply and attach to the cells lining your urinary tract.
- Overactive bladder. Decreasing fluid intake by 25% helped people with overactive bladder reduce how often and urgently they needed to pee during the day and at night.
- Hypotension. People who drank an extra 30 milliliters of fluid per kilogram of body weight (about 0.5 ounces per pound) increased their arterial pressure. That can be good for people prone to hypotension – very low blood pressure that can make you feel faint.
Credit: webmd.com
