Health: 6 Myths About Hydration

July 2nd, 2021

You may not be as thirsty as you think!


Little girl with a glass of water practicing hydration Image

As the weather warms, you’ve probably got your water bottle out. And that’s a good thing. “Every single cell in your body needs fluid to function properly,” says Angie Eakin, M.D., a family medicine physician in Spokane, Washington. “That’s why even mild dehydration can make you irritable, foggy-headed and headachy.” But while it’s smart to keep sipping, a lot of conventional wisdom about hydration is just plain false. Read on for the eye-opening scoop.

Myth: We’re all chronically dehydrated.

Fact: Not if you eat a healthy diet.

Moisture in food contributes about 20% of the fluid you need. So if you avoid “dry” foods like heavily processed crackers, fill up on fruits and veggies and drink when you’re thirsty, you should stay well hydrated, even if you’re not chugalugging, explains Barbara Rolls, Ph.D., a nutrition professor at Pennsylvania State University.

Myth: It’s easy to mistake thirst for hunger.

Fact: Your body knows the difference.

You’re unlikely to mix up true thirst and hunger because the sensations aren’t even similar. “They feel different and are regulated by separate mechanisms in your body,” says Rolls. When you’re low on fluids, your cell and blood volumes decrease, and you get an unpleasantly dry, tacky-feeling mouth. Hunger, on the other hand, is driven by gut hormones, nutrients and glucose, and it’s heralded by stomach rumbles and a sensation of emptiness.

Myth: You need to drink 64 ounces of water a day — at least – for good hydration.

Fact: That’s a random number.

“There’s not a lot of hard-core evidence that you have to drink this amount,” says Eakin. You might need more if you live in a hot and humid climate, exercise a ton or are pregnant. Most healthy adults will hit the right amount by following their own thirst cues.

Myth: Thirsty? You’re already dehydrated.

Fact: You could use a drink, but it’s not a crisis.

Folks who tout this myth would have you believe that thirst is something you should never feel, ever. But thirst is simply your body’s way of saying, “Hey, maybe you ought to take a swig from your water bottle.” It’s OK to feel a little thirsty — just don’t wait too long to grab a drink. Actual dehydration (the kind that endangers your health) comes with more serious ill effects, like migraines and dizziness.

Myth: You should drink a lot during exercise.

Fact: Let thirst be your guide.

You may think it’s good to glug loads of water during spin class — or that it can’t hurt. But there is such a thing as overhydration. Hyponatremia, in which the level of sodium in your blood gets too low, can be caused by drinking large volumes of fluid, even with electrolytes. It’s rare, but it can be deadly. “There is no reason to drink more than your body needs, and the sensor that tells us how much we need is thirst,” says Mitchell Rosner, M.D., professor of medicine at the University of Virginia Health System.

Myth: Drinking water will curb your appetite.

Fact: Maybe, but not for the reason you think.

Though eating soup or another water-rich food at the start of a meal will fill you up and help you consume fewer calories overall, “plain water empties out of your stomach quickly,” says Rolls. However, she points out, research shows that if you believe water can tame your appetite, it might.


And for even more wellness tips, visit our health page!


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