Lead author Juliana Cohen, research fellow in the Department of Nutrition at the Harvard School of Public Health, said the study, the first to examine school food consumption both before and after the standards went into effect, contradicted criticisms the new standards increased food waste.
"There is a push from some organizations and lawmakers to weaken the new standards," Cohen said in a statement. "We hope the findings, which show that students are consuming more fruits and vegetables, will discourage those efforts."
The researchers collected plate waste data among 1,030 students in four schools in an urban, low-income school district both before and after the new standards went into effect.
The study, published in the American Journal of Preventive Medicine, found following the implementation of the new standards in 2012, fruit selection increased by 23 percent; while entree and vegetable selection remained unchanged.
However, consumption of vegetables increased by 16.2 percent; fruit consumption was unchanged, but because more students selected fruit, overall, more fruit was consumed after the implementation of the new standard.
The new standards did not result in increased food waste, contradicting anecdotal reports from food service directors, teachers, parents and students that the regulations were causing an increase in waste due to both larger portion sizes and the requirement that students select a fruit or vegetable.
However, high levels of fruit and vegetable waste have always been a problem -- students throw out some 60 percent to 75 percent of vegetables and 40 percent of fruits on their trays.
"The new school meal standards are the strongest implemented by the U.S. Department of Agriculture to date, and the improved dietary intakes will likely have important health implications for children," the study authors wrote.