Although some elementary school students complained about more nutritious school lunches when they were first introduced in 2012, they like them now, according to a peer-reviewed study in Childhood Obesity released Monday.

More than 500 public schools participated in the study with most coming from the southern region of the United States and rural areas.

Researchers at the University of Illinois at Chicago surveyed administrators about the students’ reactions to new meals with standards s presented in the 2012-2013 school year. The new standards required that half of grains offered must be whole-grains, both a fruit and vegetable must be offered daily, milk must be nonfat or low-fat, and no trans-fats. The rules were created to address childhood obesity and were given a public relations push by First Lady Michelle Obama.

The study found that 70 percent of schools reported that students seem to like their new lunches. Fifty-six percent said that students complained at first, while 64 percent of schools agree that few students continue to complain about the lunches. Sixty-three percent of students are no longer concerned about the new changes, according to the research.

“This significant study reinforces what we have known all along:  America’s school lunch program works,” said American Heart Association CEO Nancy Brown.  “We hope this sends a strong message to Congress that schools should not be allowed to withdraw from or delay any federal nutrition standards.  By doing so, we may forfeit the fight against childhood obesity, and jeopardize our kids’ health.”

Urban and suburban elementary and middle schools reported fewer student complaints and less waste than did rural schools. Urban and suburban elementary schools also were less likely to report decreases in the number of students who purchased lunch.

Those with higher socioeconomic standing appear to buy their school lunch less often than those with lower socioeconomic status.

Rural areas generated the highest numbers of complaints and respondents perceived that students in those areas purchased and consumed fewer meals. This highlighted concerns since rural areas have higher rates of childhood obesity and an overall reduced life expectancy. Those same areas often do not have as many policies in place to help provide healthy school environments compared to suburban and urban areas, according to the study.

Pizza seemed to be the igniting factor for complaints. Schools that didn’t serve the lunch time favorite had more complaints.

During the 2006-2007 school year, nearly all schools offered pizza.  That number dropped to 47 percent of public elementary schools now offering regular pizza, while roughly 85 percent of schools offer a healthier version of pizza.

The students were fine with the healthier versions of pizza. Instead, the complaints were generated when children were upset that pizza had fallen off the menu.

The data came from surveys mailed to principals in January of each school year.  The surveys were reviewed and approved by the institutional review board at the University of Illinois at Chicago and were made at the Institute for Social Research at the University of Michigan.  All public elementary schools in the nation that had a third grade class of at least 20 students were eligible for the survey.

An accompanying research brief out of the University of Michigan found similar results in middle and high schools.

The changes to school lunch standards is still under debate in Washington, where opponents have said the program loses money. A hearing on school nutrition is planned on Wednesday before the Senate Committee on Agriculture, Nutrition and Forestry.