The growing share of so-called sports drinks are little more than sugar water with added salt, said Margo G. Wootan, director of nutrition policy at the Center for Science in the Public Interest in Washington.
"The good news is that soft drinks sales are declining in schools," Wooten said in a statement. "The bad news is the majority of school beverages are still sugary drinks -- and soft drinks are the No. 1 source of calories in teens’ diets."
The increase in bottled water sales is good news but given that two-thirds of high school beverage sales are still sugary drinks, voluntary industry action coupled with state and local policies aren't enough to solve the problem, said Wootan.