Strong State Laws on School Snacks, Drinks May Help to Prevent Weight Gain, New Study Finds

    • August 15, 2012

Princeton, N.J. Children and teens in states with strong laws restricting the sale of unhealthy snack foods and beverages in school gained less weight over a three-year period than those living in states with no such policies, according to a study published online today in the journal Pediatrics. Additionally, students who were overweight or obese in 5th grade were less likely to remain so by the time they reached 8thgrade if they lived in a state with a strong law than if they lived in a state with no such law.

To conduct the study, researchers examined state laws regarding what snack foods and beverages could be sold in schools outside of the federal school meals program. State laws requiring schools to sell only snacks that met specific nutrition standards were classified as “strong” policies. Policies were classified as “weak” if they merely recommended that schools make changes, or if they did not create specific nutritional guidelines, relying instead on general language about “healthy” foods.

Students exposed to strong snack food and beverage laws throughout the three years of the study had the smallest increases in body mass index (BMI), a ratio of height to weight. Those who were exposed to weaker laws over time saw the same change in their BMIs as did students living in states with no policies at all.

“Specific, consistent requirements about what types of snack foods and drinks can be sold at school seemed to have a direct impact on student weight,” said Daniel Taber, PhD, a researcher at the University of Illinois at Chicago and lead author of the study. “This study definitely suggests that states can have an impact on student health when they enact effective school health policies.” Taber is a co-investigator with Bridging the Gap, a research program of the Robert Wood Johnson Foundation (RWJF), which funded the study.

Many schools sell snacks and drinks in vending machines, school stores or cafeteria à la carte lines. These items are sometimes called “competitive foods” because they compete with school meals for students’ spending. In recent years, states have begun to pass laws that prohibit schools from selling certain foods or drinks, or laws that set limits for the fat, salt, sugar or calorie content of items. For instance, schools have begun to replace unhealthy items, such as sodas and candy, with healthier choices, such as low-fat milks and fruit.

Despite state action, today there is only a very limited national standard for snack foods and beverages in schools. Passed in 1979, the standard prohibits schools from selling things like candy or gum in the cafeteria during lunch. The Healthy, Hunger-Free Kids Act of 2010 enabled the U.S. Department of Agriculture (USDA) to update the standard so that it aligns with the 2010 Dietary Guidelines for Americans, but the USDA has yet to do so.

This is the first longitudinal study to examine the impact of snack and drink policies on student weight using completely objective data. Similar past studies have used either self-reported height and weight, or interviews with school principals about policies, either of which could result in weaker evidence.

Taber and his colleagues at Bridging the Gap and the National Cancer Institute used several databases of state laws to analyze the strength of school snack policies. They scored each based on how specific it was and whether it required action from schools or merely made recommendations. To calculate student BMI, they used objective height and weight measurements from 6,300 students in 40 states. The measurements were done in the spring of 2004, when students were in 5th grade, and again in the spring of 2007, when they were in 8th grade.

Students exposed to strong laws in 5th grade gained an average of 0.25 fewer BMI units over three years than did students in states with no policies at all. That equates to roughly 1.25 fewer pounds for a child who was 5 feet tall and weighed 100 pounds. Students who lived in states with strong laws throughout the entire three-year period gained an average of 0.44 fewer BMI units than those in states with no policies, or roughly 2.25 fewer pounds for a 5-foot-tall, 100-pound child.

“It’s encouraging to see that strong state laws can help students maintain healthier weights,” said C. Tracy Orleans, PhD, senior scientist at RWJF. “However, because not all students live in states with effective policies, we need to make sure that we get a strong national policy in place.”

Taber and his colleagues note that the laws that were most effective were those that set strong standards at both the elementary- and middle-school levels. Currently, many states have stronger laws at the elementary level than at middle school. Ensuring that students have healthy school environments as they age is likely to be effective in helping them stay healthy, the authors concluded.

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About Bridging the Gap

Bridging the Gap is a nationally recognized research program dedicated to improving the understanding of how policies and environmental factors influence diet, physical activity and obesity among youth, as well as youth tobacco use. For more information, visit


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The Robert Wood Johnson Foundation focuses on the pressing health and health care issues facing our country. As the nation’s largest philanthropy devoted exclusively to health and health care, the Foundation works with a diverse group of organizations and individuals to identify solutions and achieve comprehensive, measurable, and timely change.

For 40 years the Foundation has brought experience, commitment, and a rigorous, balanced approach to the problems that affect the health and health care of those it serves. When it comes to helping Americans lead healthier lives and get the care they need, the Foundation expects to make a difference in your lifetime. For more information, visit www.rwjf.orgFollow the Foundation on Twitter or Facebook