While New York mayor Michael Bloomberg is busy proposing the ban on super-sized sugary drinks to change the food habits of the youth in the city, revelations of a study by University of Michigan may help in strengthening his stand.

According to the study, though only half as many as adolescents in 2006 can still buy high-calorie sodas in schools, but other sugary beverages remain easily available onsite, reports Reuters.

The trend was observed in the survey of more than 1,900 public schools conducted by University of Michigan Ann Arbor researchers. The trend has grown as the institutions banish sodas from vending machines, school stores and cafeterias.

"Public school districts really have been getting the message that regular sodas are not a good thing for our kids to be drinking," said Yvonne Terry-McElrath, the study's lead author and a researcher at the university's Institute for Social Research.

The results reflect a nationwide trend as consumers move away from traditional, carbonated soda to other, noncarbonated drinks that consumers view as healthier but that can still pack excess calories and sugar.

U.S. high schools typically include 14 to 17-year-olds, while middle schoolers are generally aged 11 to 13.

Older students who could buy soda in high school fell to 25 percent in 2011 from 54 percent in 2006, while access by younger middle school students fell to 13 percent from 27 percent, according to the study published in the Archives of Pediatrics & Adolescent Medicine Monday.

But fruit drinks, sports drinks and other beverages with added sugar and calories that could lead to obesity over time can still be bought easily in schools.

The university's study found sports drinks such as PepsiCo Inc's Gatorade and The Coca-Cola Co's Powerade are still a concern when it comes to older students.

"In general, people still perceive sports drinks as a health option for kids," Terry-McElrath said.

More than half of middle school students -55 percent and most high school students -83 percent could still buy the drinks in the 2010-2011 academic year, which ended last June, it showed.

While that is a decline from 72 percent of middle schoolers and 90 percent of high schoolers in 2006-2007, the numbers are still too high, researchers said. Medical experts have said sports drinks should be limited to people doing intense exercise.

The study was funded by the Robert Wood Johnson Foundation, a philanthropic organization aimed at improving U.S. health.