Less than 2% of middle school and less than 1% of high school students attend public schools that adhere to all five components of the U.S. Department of Agriculture nutritional standards for schools, according to a report published online Nov. 17 in JAMA Pediatrics.

Beginning with the current school year, schools participating in federally reimbursable meal programs must implement the USDA nutritional standards for foods and drinks sold in school stores, snack bars, vending machines, food carts, a la carte cafeteria lines, and at sporting and other events – not just in cafeterias.

The standards, developed in response to the obesity epidemic among American children and adolescents, include five components: eliminate all sugar-sweetened beverages, eliminate all whole and 2% milk (i.e., offer only skim milk), eliminate all candy and regular-fat (as opposed to low-fat) snacks, eliminate French fries, and make fruits or vegetables available in all food venues, said Yvonne M. Terry-McElrath of the Institute for Social Research, University of Michigan, Ann Arbor, and her associates.

To assess adherence to these standards before the requirement takes effect, the investigators analyzed questionnaire responses from nationally representative samples of 22,716 middle school students, 30,596 high school students, and school administrators during a 5-year period.

Only 1.8% of middle school and 0.3% of high school students attended schools that complied with all five components of the USDA nutritional standards. Conversely, 21% of middle and 30% of high school students attended schools that failed to comply with any of the five components. The mean number of components that were adhered to was 1.59 for middle schools and 1.27 for high schools. The components that most schools complied with were eliminating French fries and offering only skim milk, the investigators said ( JAMA Pediatrics 2014 Nov. 17 [doi:10.1001/jamapediatrics.2014.2048] ). High school students whose schools had fruits or vegetables available, offered only skim milk, or complied with three or more of the components had modestly but significantly lower odds of being overweight or obese. For example, the probability that students in somewhat compliant schools would be overweight or obese was estimated to be 25.4%, while that of students in noncompliant schools was 27.7%. Taken together, these findings suggest that fully implementing the USDA nutritional standards would make a measurable improvement in student body mass index across the country, Ms. Terry-McElrath and her associates noted. Ms. Terry-McElrath and her associates reported having no financial disclosures.