Eat Smart, Move More South Carolina

Adolescents in states with strict laws regulating the sale of snacks and sugary drinks in public schools gained less weight over a three-year period than those living in states with no such laws, a new study has found. The study, published Monday in Pediatrics, found a strong association between healthier weight and tough state laws regulating food in vending machines, snack bars and other venues that were not part of the regular school meal programs. Such snacks and drinks are known as competitive foods, because they compete with school breakfasts and lunches.The conclusions are likely to further stoke the debate over what will help reduce obesity rates, which have been rising drastically in the United States since the 1980s. So far, very little has proved effective and rates have remained stubbornly high. About a fifth of American children are obese, according to the Centers for Disease Control and Prevention.

Public health experts have urged local and state governments to remove competitive foods from schools, and in recent years states have started to pass laws that restrict their sale, either banning them outright or setting limits on the amount of sugar, fat or calories they contain.

The study tracked weight changes for 6,300 students in 40 states between 2004 and 2007, following them from fifth to eighth grade. They used the results to compare weight change over time in states with no laws regulating such food against those in states with strong laws and those with weak laws.

Researchers used a legal database to analyze state laws. Strong laws were defined as those that set out detailed nutrition standards. Laws were weak if they merely offered recommendations about foods for sale, for example, saying they should be healthy but not providing specific guidelines.

The study stopped short of saying the stronger laws were directly responsible for the better outcomes. It concluded only that such outcomes tended to happen in states with stronger laws, but that the outcomes were not necessarily the result of those laws. However, researchers added that they controlled for a number of factors that would have influenced outcomes.

Still, the correlation was substantial, researchers said, suggesting that the laws might be a factor. Students who lived in states with strong laws throughout the entire three-year period gained an average of 0.44 fewer body mass index units, or roughly 2.25 fewer pounds for a 5-foot-tall child, than adolescents in states with no policies.

The study also found that obese fifth graders who lived in states with stronger laws were more likely to reach a healthy weight by the eighth grade than those living in states with no laws. Students exposed to weaker laws, however, had weight gains that were not different from those of students in states with no laws at all.

The authors argued that the study offered evidence that local policies could be effective tools.

“Competitive-food laws can have an effect on obesity rates if the laws are specific, required and consistent,” said Daniel Taber, a fellow at the Institute for Health Research and Policy at the University of Illinois at Chicago, who was one of the authors of the study.

Still, many states have no laws at all regulating the sale of such foods, and the group that helped finance the study, the Robert Wood Johnson Foundation, argued that the results made the case for a strong national standard for snacks and beverages in schools. The United States Department of Agriculture has been developing new standards for some time, but they have yet to emerge.

Some experts argue that a real reduction in the obesity rate will come only when many more local governments adopt tough policies to change the food environment. Still others say that school is such a small part of a child’s day that healthier options will make little difference when coupled with a home environment with a lot of unhealthy choices.