(Reuters Health) - More than half of U.S. high school students still have sports drinks at least once a week and their ranks are growing, although a new study suggests fewer teens have these sugary, calorie-laden beverages every day.

Sports drinks are aggressively marketed to teens to replenish fluids or electrolytes, a message that many adolescents and their parents mistakenly believe, researchers note in Pediatrics. Doctors recommend water instead for hydration, and warn families to avoid drinks with lots of calories and sugar because of an increased risk of chronic health problems like obesity and diabetes.

For the current study, researchers examined data from nationally representative surveys done in 2010 and 2015 with a total of 27,000 high school participants.

Overall, the proportion of teens who reported having sports drinks at least once in the previous week rose from 56 percent in 2010 to almost 58 percent in 2015, a slight but statistically meaningful difference.

“It is possible that this may be because sugar-sweetened sodas are less available in schools and teens are turning to sports drinks instead,” said senior study author Dr. Andrew Adesman of the Steven & Alexandra Cohen Children’s Medical Center of New York and Northwell Health.

“The increase in weekly consumption may also be a result of the aggressive advertising and marketing campaigns that are often focused on teens,” Adesman said by email.

Over the same period, the proportion of teens drinking sports drinks daily declined from slightly more than 16 percent to almost 14 percent, the study also found.

“To the extent that daily consumption is a greater concern with respect to the total amount of unnecessary calories, the downward trend is encouraging and it may be because teens and their parents are increasingly recognizing that the typical teen who is physically active or athletically engaged does not need to rehydrate with sports drinks,” Adesman added.

Daily sports drink consumption didn’t decline, however, for obese teens, and it increased among adolescents who spent more than two hours a day watching television, the researchers found.

The study wasn’t a controlled experiment designed to prove whether or how any shifts in advertising or attitudes about sports drinks might have influenced teens.

“I do think that the marketing of these drinks as part of a lifestyle that is not just active - but includes extreme fitness and excellence in sports - influences teens,” said Jennifer Emond, a researcher at the Geisel School of Medicine at Dartmouth College in Lebanon, New Hampshire, who wasn’t involved in the study.

“It comes across as an aspirational product,” Emond said by email.

Beyond the lure of advertising, sports drinks are also becoming more popular in part because other options popular with teens are becoming scarce in schools, said Dr. Megan Pesch, a researcher at the University of Michigan’s C.S. Mott Children’s Hospital in Ann Arbor.

“During the last decade there has been an increase in bans on sugar sweetened beverages (SSBs) sold in schools,” Pesch, who wasn’t involved in the study, said by email.

“Even though sports drinks are in fact SSBs similar to juice and soda, as they contain added sugars, they have not typically been included in these bans,” Pesch added. “This increase in the rate of sports drink consumption by teens nationally indicates that they may be replacing one type of SSB for another.”

Still, parents can teach children and teens what’s healthy to drink, said Marie Bragg, a researcher at New York University School of Medicine who wasn’t involved in the study.

“Parents can help kids drink smart by teaching them to take a look at nutrition labels or compare the amount of sugar in soda and sports drinks (hint: they both have a lot!),” Bragg said by email. “Parents can also make a statement with their wallets by purchasing no-calorie beverages for their kids and encouraging tap water consumption.”

SOURCE: bit.ly/2wla93J Pediatrics, online May 7, 2018.