BOSTON (AP) - A new study indicates that the Boston public schools' ban on sugary drinks has paid off, with high school students drinking fewer even when they're not at school.
In 2004, Boston public schools banned the on-campus sale of sugar-sweetened beverages, such as soda, sports drinks and fruit drinks.
The study, funded by the Robert Wood Johnson Foundation, tracked ninth- through 12th-graders for two years after the ban began. It found sugar-sweetened beverage consumption, inside and outside school, fell from an average of 1.71 servings per day in 2004 to 1.38 servings in 2006, according to results in a press release Tuesday. The study was released in July.
That's roughly 45 fewer calories daily, enough to eliminate up to 40 percent of the excess calories blamed for the rising average weight in U.S. children, the study said.
By comparison, nationwide there was no statistically significant decrease in teens' sugary-drink consumption between the 2003-04 and 2005-06 school years, according to the study.
"This study shows that a very simple policy change can have a big impact on student behavior," said the study's lead author, Angie Cradock, a senior research scientist at the Harvard School of Public Health. "It also shows that when students couldn't get these unhealthy beverages in school, they didn't necessarily buy them elsewhere."
The study supports what's becoming a broader movement with potentially huge health and cost benefits - if it can reduce obesity and corresponding problems such as heart disease and diabetes, said Dr. Georges Benjamin, executive director of the American Public Health Association.
The idea is "to make the healthy choice the easy choice," Benjamin said. "What you're seeing is that people are drinking the stuff that isn't as sweet and they become comfortable with that, and that becomes a choice."
Helen Mont-Ferguson, who was director of nutrition services at Boston schools when the ban was enacted, said not having the sweet drinks only partly explains their dropping popularity outside school. She said schools also focused on educating students on the abundant amounts of sugar in the drinks they were downing and on pushing alternatives such as water.
"They really did listen and there are behavioral changes that are taking place," she said.
Researchers surveyed more than 1,000 students at 17 Boston high schools for the study, which defined a serving as one can or glass, with a 20-ounce bottle counting as two servings. They also highlighted possible study limitations, including the fact that before the ban Boston students may have had relatively limited access to alternatives for sugary drinks, compared to other communities. Only 14 percent of the city's public schools gave students access to water fountains in 2006-07, though bottled water was available.
Mayor Thomas Menino has expanded the ban on the sale of sugary drinks outside Boston schools to all city property with an executive order in April. Under the order, the expanded ban is scheduled to take effect in October.
And just last month, the Massachusetts Public Health Council passed new nutrition standards that take sugary sodas out of schools statewide and kick an array of other foods off school property, including those with artificial sweeteners, trans fats and caffeine.
The statewide changes go into effect between the 2012-13 and 2013-14 school years.