Researchers at the University of Illinois at Chicago looked at the association between established policies and laws and the availability of candy, baked goods, ice cream, chips, sugar-sweetened beverages, and soda sold outside the school meal program. More than 1,800 elementary schools in 45 states responded to surveys during the 2008-2009 and 2010-2011 school years.

The researchers found that in schools without district or state guidelines limiting sugar content in foods, 43.5 percent sold sweets. When both district and state guidelines restricted the sale of sweets, only 32.3 percent of schools -- nearly a quarter fewer -- sold these foods.

The study shows that "policies can improve the elementary school food and beverage environment, and state and district policies are often reinforcing one another," says Jamie Chriqui, lead author of the study and senior research scientist at UIC's Institute for Health Research and Policy.

Sugar-sweetened beverages were available in only one-fourth as many schools that had a district-wide ban as in those that had no policy (3.6 percent and 13.1 percent of schools, respectively). But the availability of sugar-sweetened beverages was not influenced by state policies.

Public elementary schools are required, through an unfunded federal mandate, to have a wellness policy with nutritional guidelines for "competitive" foods and beverages -- those that vie with items in the school meal program.

"Given the problems we have with overconsumption of sugar-sweetened beverages by children and youth, the fact that unfunded district policies are actually helping to change the availability of sugar sweetened beverages in elementary schools is a really positive sign," said Chriqui.

However, the study also revealed that the policies are not being fully implemented. For example, the researchers found that of the 121 surveyed schools that were in states with laws prohibiting sale of sugar-sweetened beverages in elementary schools, 22 schools -- all in southern states -- still sold sugar-sweetened beverages despite state-wide bans.

The U.S. Department of Agriculture is working to implement nationwide standards governing competitive foods and beverages in schools as part of the Healthy, Hunger-Free Kids Act of 2010.

"There is a lot of room for continued progress," said Chriqui, who noted that the study provides promising data to guide the USDA's efforts to impose new federal standards for competitive foods and beverages.

Co-authors include Lindsey Turner, Daniel Taber and Frank Chaloupka, all of UIC.

The study was supported in part by the Robert Wood Johnson Foundation to the Bridging the Gap Program at UIC.