Most kids and teens in the United States are not drinking enough fluids, leaving them at least mildly dehydrated, according to a new study published in the American Journal of Public Health.

We know that many kids are consuming too many sugary drinks. But researchers were surprised to find out that out of kids ages 6 to 19, a quarter of them reported that they never drink water.

Harvard scientists examined data from the National Health and Nutrition Examination Survey. In addition to a variety of information from participants, urine tests are also examined, which reveal how hydrated people are. The researchers report in the study that more than half of the several thousand students studied between 2009 and 2012 were dehydrated, at least slightly.

“This doesn’t mean we’re saying kids are dropping like flies or that they’re very seriously dehydrated and need to go to the hospital or anything like that,” postdoctoral researcher Erica Kenney at Harvard’s T.H. Chan School of Public Health told NPR. Even if it’s not super serious, Kenney says mild dehydration can affect mood, ability to concentrate or learn and energy levels.

“It was astounding to me,” Kenney said about the fact that so many children said they drink no water at all. “And even among the kids who were drinking water — they weren’t drinking very much of it.”

According to The Institute of Medicine, kids and teenagers should consume about two to three quarts of water a day.

“That’s total water, so that can be from any beverages — any water that’s in your food like soups, juicy fruits and vegetables, things like that,” Kenney said.

Kenney pointed out that drinking more water isn’t always as easy as it sounds for kids. In some schools, older plumbing could eliminate tap water as an option, and bottled water or water in jugs is expensive. While attempting to cut down sugary drinks, schools can ideally put in more effort to provide drinking water – through a fountain drink-type dispenser could be an option.

Photo: Flickr user Andreas Levers