If the latest U.S. Department of Agriculture (USDA) standards for school meals and food sold in other venues such as vending machines and snack bars are fully implemented, there is potential to substantially improve school nutrition because only a small fraction of students attended schools with five USDA healthy nutritional components in place from 2008 through 2012, according to a study published online by JAMA Pediatrics.

The USDA recently issued updated standards to improve nutrition in federally reimbursable meal programs for school lunches and breakfasts. The USDA standards limit fat, sodium, sugar and calories; final implementation of the standards essentially will remove student access to candy, salty snacks, sugary treats, milk with higher levels of fat, savory foods with high levels of fat and calories, and sugar-sweetened beverages (SSBs). Most lunch standards were implemented at the beginning of the 2012-2013 school year and breakfast requirements were gradually implemented beginning in the 2013-2014 school year. Beginning with the 2014-2015 school year, schools in the meal programs are required to implement nutritional standards for food and beverages sold in "competitive venues," such as vending machines and snack bars. The USDA standards were in response to rising overweight-obesity among American children, but some experts oppose their implementation, according to background information in the study.

Yvonne M. Terry-McElrath, M.S.A., of the University of Michigan, Ann Arbor, and her fellow co-authors analyzed five years of nationally representative data from middle and high school students and from school administrators to examine what percentage of U.S. secondary school students attended schools with specific USDA components from 2008 through 2012, whether the components were associated with student overweight-obesity, and whether there were differences based on sociodemographic characteristics.

The analytic sample included 22,716 eighth-grade students in 313 schools and 30,596 10th- and 12th-grade students in 511 schools. The USDA nutritional components the authors analyzed were no SSBs, no whole/2 percent milk, no candy or regular-fat snacks, no French fries and a fifth component that was encouraged, but not required by the USDA standards, was that fruits or vegetables be available wherever food was sold.

Among the students, an average of 26.4 percent of middle school students and 27.1 percent of high school students were classified as overweight/obese.

The study findings show that 21.1 percent of middle schoolers and 30.1 percent of high schoolers attended schools without any of the components from the 2007-2008 through 2011-2012 school years. Schools with all five of the nutritional components were attended by only 1.8 percent and 0.3 percent of middle and high school students, respectively. The nutritional component most often present in schools was the absence of French fries (57.7 percent of middle school and 44.9 percent of high school students attended schools without French fries).

The authors found no significant associations between the USDA standard components and self-reported overweight/obesity among middle school students overall. However, among high school students lower odds of overweight/obesity were associated with having fruits or vegetables available wherever food was sold, the absence of higher-fat milk and having three or more USDA nutritional standard components. For Hispanic middle school students and nonwhite high school students there was an association between the absence of SSBs and lower overweight/obesity.

"Results illustrate that the USDA standards - if implemented fully and monitored for compliance - have the potential to change the current U.S. school nutritional environment significantly," the study concludes.

Editorial: Considering the Potential Effect of Federal Policy on Childhood Obesity

In a related editorial, Leslie A. Lytle, Ph.D., of the University of North Carolina at Chapel Hill, writes: "School administrators have been slow to adopt the belief and related policies and practices that unhealthy foods that are high in sugar, fat and empty calories do not belong in a school and that providing fruit, vegetables and whole-grain products throughout the school is important."

"The new federal policy may be a carrot at the end of the stick that drives schools to make these important changes. In addition to the stick-and-carrot, substantial tangible help in making the switch and incentives to sweeten the deal from state and federal sources are likely needed," the author concludes.