MONDAY, Jan. 4, 2016 (HealthDay News) -- Move over, mystery meat -- students are choosing more nutritious school lunches under the Healthy Hunger-Free Kids Act, new research suggests.
"We found that the implementation of the new meal standards was associated with the improved nutritional quality of meals selected by students," according to study author Donna Johnson, from the University of Washington's Nutritional Sciences Program.
"These changes appeared to be driven primarily by the increase in variety, portion size and the number of servings of fruits and vegetables," the researchers wrote in a report published Jan. 4 in JAMA Pediatrics.
The 2010 Healthy Hunger-Free Kids Act updated nutritional standards for the National School Lunch Program and the School Breakfast Program. The revised guidelines took effect for the 2012-13 school year. They increased the availability of whole grains, fruits and vegetables, and created other food requirements. The national lunch program serves more than 31 million students daily, the researchers said in a journal news release.
The updated nutritional standards appeared to have no negative effects on kids' participation in school meal programs, Johnson's team said.
The study looked at the nutritional quality of the foods students chose. The investigators also looked at how many kids ate school meals before and after implementation of the new regulations.
Overall, the research team examined changes in more than 1.7 million lunches at three middle school and three high schools in an urban school district in Washington state from 2011 to 2014.
The nutritional quality of the foods was estimated using a measure that included calcium, vitamin A, vitamin C, iron, fiber and protein. The researchers also looked at the energy density of foods. Items with lower energy density have fewer calories per gram, the researchers said.
The study found a significant increase in the nutritional quality of the foods. And, the energy density of foods decreased, the study revealed.
Meal participation was 47 percent before the updated guidelines and 46 percent after the changes were made, the research showed. However, the researchers said their findings only showed what foods were selected by students, not necessarily what they ate.
The study authors also pointed out that because the study only included one urban school district, the results may not apply to schools in other areas.
The U.S. Centers for Disease Control and Prevention has more about students' nutritional needs.