Q: Is it true that everyone needs to drink eight 8-oz. glasses of water daily? —Gwyneth H., Orlando, Fla.
A: Actually, that’s a popular misconception. Some people are more active and need more water. Some need less. Your body is designed to let you know—despite all the advice you see from “experts,” thirst is still your best guide for how much water to drink daily.
That said, many of us do not drink enough water to stay hydrated, partly because we have so many other options. And a Diet Pepsi is often less expensive to buy than water, which is crazy!
Why We Need It
Healthy bodies contain 10–12 gallons of water, which is 50–70 percent of our body weight. Blood is 85 percent water; muscles average about 80 percent water; and the brain clocks in at 75 percent water. Even our bones are 25 percent water.
Besides its contributions to circulation and detoxification, water plays many key roles in the body, including helping proteins to fold (from amino acid chains into their functional structures), helping to make enzymes (the catalysts for all biochemical reactions), and helping our cells respond to environmental stimuli. Without enough HO, none of these systems can be healthy. Low water intake increases risk for kidney stones, bladder and colon cancers, and other health issues.
So, how much water is enough to drink? Again, let thirst be your guide. Contrary to popular myth, you won’t become dehydrated before your thirst mechanism kicks in. Some people, however, confuse thirst for hunger, so beware that urge to start snacking. Try a nice, cold glass of water instead.
In fact, I strongly recommend drinking a big glass of water first thing in the morning to “open” the sense of thirst. Don’t chug water during meals, when you want the full, undiluted force of digestive enzymes working to break down food. If your urine is darker than pale yellow, you may need more water, although it’s normal for the first morning urine to be a bit darker and smellier. And vitamin B (riboflavin) will make the urine a bright yellow color for a while after you take it.
Certain activities are reliably dehydrating, including engaging in strenuous exercise (a great time to drink extra water), travelling by airplane, and eating dry or processed foods. The combination of elevation and high speed is extremely dehydrating while flying. Dried foods require water to be properly digested, and I don’t recommend eating them when there are other options. If you like to travel with dried food, try to rehydrate it in water for 10–12 hours overnight before consuming. Rice cakes and jerky also demand more water intake, so factor that in if you enjoy these snacks.
The ban on water at airport security checkpoints poses a challenge, but many airports now have water-bottle refilling stations that you can take advantage of after you pass through security. This is a better option than buying water (or any other consumable) that has been stored in plastic. Hot beverages in plastic (Styrofoam is the worst) are especially noxious because heat (and freezing) will break down the petrochemicals in the plastic, which will then be absorbed into your tissues.