Sugary soft drinks and juices linked to bulging waistlines have all but disappeared from Boston’s public schools after a major push began years ago to banish the drinks, according to a study published Thursday that calls the city’s strict rules a model for the nation.
Only 4 percent of Boston students have access to sugar-sweetened beverages, said researchers, who examined compliance with a 2004 policy banning the sale of soft drinks, fruit drinks, sweetened teas, and sports drinks in schools. Consumption of such beverages has been strongly linked with obesity.
“The Boston public schools have always been ahead of the curve, particularly on health and nutrition,” said Rebecca S. Mozaffarian, lead author of the study and a nutrition researcher at the Harvard T.H. Chan School of Public Health.
Boston’s success, she said, can guide school districts across the nation as they roll out federal rules on sugary beverages that took effect during the 2014-2015 school year.
Published in Preventing Chronic Disease, a publication of the US Centers for Disease Control and Prevention, the research took place in 2013, nine years after the Boston School Committee adopted the standards.
Mozaffarian said she was surprised at the magnitude of the difference between Boston and the rest of nation regarding access to sugary drinks in school. Nationwide, only about 40 percent of school districts ban soda, and fewer than 20 percent of elementary and 10 percent of middle or high schools ban other types of sugar-sweetened beverages, such as fruit drinks, according to the study.
As a result, 89 percent of high schoolers nationwide have access to sugar-sweetened beverages at school — compared with only 10.5 percent in Boston’s high schools, Mozaffarian said.
The researchers did not examine whether the policies affected obesity rates. But they cited other research suggesting the ban did affect the amount of sugary beverages Boston students drink.
In 2006, two years after the ban went into effect, a study found that Boston high schoolers had reduced their consumption of sugar-sweetened beverages, while no such decline was happening nationally. In 2013, a national survey showed that 17 percent of Boston high school students had one serving or more of sugar-sweetened beverages, compared with 27 percent of high schoolers in 42 states.
Boston’s policies apply to beverages sold outside of the school meals programs, in vending machines, a la carte lines, school stores, and snack bars. The rules allow only water to be sold in elementary schools. Middle schoolers and high schoolers can also buy milk and 100 percent fruit juice, but only in certain sizes and with limitations on fat content and flavoring for milk.
The study found 90 percent of the district’s 115 schools comply — most simply by not selling beverages at all, even bottled water, the rest by selling only those that meet the rules. Only three schools were found to be selling sugar-sweetened beverages; they were not identified. Nine were out of compliance by selling 100 percent fruit juice, milk that didn’t meet the standards, or artificially sweetened waters.
Boston’s policies are stricter than the new rules from the US Department of Agriculture, which allow milk and juice in elementary schools and low-calorie and caffeinated beverages in high school.
The city kept its policy working, the researchers said, through a sustained education and training effort that included a “tool kit” containing letters, fliers, posters, and other materials helping each school implement the program. Schools that violate the rules are given refresher training.
“It’s amazing that after 10 years, Harvard [researchers] went in and were able to document such outstanding compliance,” said Jill Carter, the Boston School Department’s executive director of health and wellness. “That only happened because everybody was on board” — teachers, principals, and parents.
Carter said no state or federal guidelines existed in 2004 when Boston adopted its first set of nutrition policies in an effort to combat obesity. Updating the policies over the years, the school department worked closely with the Boston Public Health Commission, which shared federal grant money.
“We had support from the top. We had collaboration from the health community,” Carter said. “We’ve tried to take a public-health approach to this, not just telling people about the policy but helping them understand why this is important.”
Dr. Caroline M. Apovian, director of the Center for Nutrition and Weight Management at Boston Medical Center, read the study with delight. “Sugar-sweetened beverages should be considered poisonous substances just like tobacco,” she said. “There is absolutely no place for sugar-sweetened beverages in a healthy diet.”
Evidence suggests sugary drinks affect perceptions of fullness and make people want to consume more, while usually providing no nutrition, Apovian said.
Michael Leidig, clinical director of the Center for Youth Wellness at the Floating Hospital for Children at Tufts Medical Center, said the Boston district’s ability to sustain the strict policy over nearly a decade can show the way for schools across the country.
“Everyone can agree we don’t need any more sugar in our diets,” Leidig said.
Leidig, who heads a weight-management program for 11- to 18-year-olds, said participants are urged to reduce consumption of sugar-sweetened beverages to just one a day. If such beverages are not available in school, that task is made much easier, he said.
The study did not address whether schools were hurt by losing income from beverage sales, a concern that has deterred other districts. Carter had no information about any such losses, except they were clearly not a problem in Boston.
Correction: An earlier version of this story misspelled Michael Leidig’s name.