The food on school lunch trays might not look a whole lot different next year.

But there’s a high probability the foods will have more salt, more fat, and fewer whole grains.

That’s the conclusion from nutrition advocates who are sharply criticizing the changes made in school lunch nutrition standards announced on Monday by the secretary of agriculture.

The agriculture secretary and supporters of the changes say the new standards will give schools more flexibility, allow for cultural-based meals in certain regions, and discourage children from throwing away a lunch they don’t find tasty.

“This announcement is the result of years of feedback from students, schools, and food service experts about the challenges they are facing in meeting the final regulations for school meals,” Agriculture Secretary, Sonny Perdue, said in a press statement.

Nutrition advocates, however, say the assertions by Perdue and supporters of the changes aren’t true.

“It’s disturbing to say the least,” Katie Ferraro, a registered dietitian and assistant clinical professor at the University of San Diego and the University of California San Francisco, told Healthline. “We’re undoing seven years of work that almost everyone agrees is a good idea.”

Read more: Battle intensifies to keep junk food out of school lunch programs »

What the new rules change

The new guidelines make changes in the regulations set forth in the 2010 Healthy Hunger-Free Kids Act.

The act was strongly endorsed by former first lady Michelle Obama.

Those rules required schools to reduce calories, fat, and sodium as well as increase the amount of whole grains in their lunch programs.

The programs feed 32 million schoolchildren who qualify for federally subsidized meals.

The new rules will allow schools to apply for exemptions beginning this fall to some of those regulations.

The exemptions include daily sodium limits, whole-grain food minimums, and a mandate on serving nonfat milk. Schools will now be able to serve 1 percent flavored milk.

Perdue, who was confirmed as agriculture secretary last week, announced the changes while visiting a school in Virginia.

Perdue said the government regulations cost school districts $1.2 billion in fiscal year 2015.

In addition, he said, the rules limit the flexibility schools have in what they serve. As an example, Perdue mentioned schools in the South that want to serve grits. However, the whole-grain version has small black flakes that schoolchildren don’t like.

“The school is compliant with the whole-grain requirements, but no one is eating the grits. That doesn’t make any sense,” said Perdue.

The agriculture secretary also said schools are reporting more students are not participating in lunch programs and are throwing away their less-tasty food.

“If kids aren't eating the food, and it’s ending up in the trash, they aren't getting any nutrition,” he said.

Perdue’s assertions were applauded by the School Nutrition Association (SNA), which represents school nutrition officials as well as companies that supply schools with food.

“I commend Secretary Perdue for taking this important step,” Patricia Montague, the association’s chief executive officer who visited the Virginia school with Perdue, said in a statement. “We have been wanting flexibility so that schools can serve meals that are both nutritious and palatable.”

Elizabeth Cowles Johnston, a spokeswoman for the SNA, told Healthline the rules were “limiting menu planning” at schools.

Besides the Southern grits, Johnston said schools in the Southwest should be able to serve flour tortillas and not be hampered by the whole-grains requirements.

She said providing flexibility to the schools is the key. She noted schools have the option to use the exemptions, but they don’t have to take them.

“I don’t think you’ll notice any significant changes,” she said. “This is not intended to go backward on the good things that have happened under this program.”

Read more: Is school lunch program a success? »

Criticism of the changes

However, going backward is exactly how school nutrition advocates describe the guideline changes.

Nancy Brown, chief executive of the American Heart Association, told The New York Times that extra sodium and sugar in school lunches will increase students’ blood pressure and put them at greater risk of heart disease and strokes.

“We’re very disappointed that the U.S.D.A. has decided to put special interests back on the school menu,” she said.

Others noted that looking out for children’s best interests is a major role of schools.

“Just because children would rather eat heavily salted, processed foods at school doesn’t mean they should,” Ken Cook, president of the Environmental Working Group, told the Times. “The president’s fondness for Big Macs and KFC is well known, but we shouldn’t let Colonel Sanders and McDonald’s run the school cafeteria.”

Officials at The Alliance for a Healthier Generation also criticized the changes.

Howell Wechsler, EdD, MPH, chief executive officer of the alliance, told Healthline that 97 percent of schools were on track to implement the guidelines specified in the 2010 act.

He said his organization has “great faith” in school nutrition officials as well as food companies in being innovative enough to provide nutritious yet tasty meals.

“We strongly believe schools can implement the nutrition standards,” he said. “Our nation and our children are better served if we stay the course.”

Wechsler also dismissed the claim made by Perdue and the SNA that more children are tossing their lunches rather than eating them.

“Children were throwing away a lot of food before this,” he said. “To act like this is a new phenomenon isn’t very credible.”

Perdue and SNA officials did not cite any data when they included food waste in their remarks on Monday.

When asked by Healthline about that data, Johnston researched the matter and sent an email with a link to a 2013-2014 U.S. Department of Agriculture study.

In the report, 60 percent of participating schools reported an increased waste of vegetables, 47 percent more waste of fruit, and 49 percent more grain waste.

However, Wechsler, who has studied the issue in the past, said most of the studies are small in scale and most show students are tossing the same amount or even less food than in the past.

Ferraro said the most important issue is what will be on school lunch trays.

She predicted children will be served more processed food with higher salt content as well as fewer items with whole grains.

She said the exemption to allow flavored milk is particularly upsetting because liquids like chocolate milk have added sugar.

“It’s a problem,” she said.

The dietitian also criticized the SNA for representing the food industry and not schoolchildren.

“They should be called the School Processed Food Association,” she remarked.

Indeed, the SNA has done an about-face on school nutrition standards.

In 2010, the association backed the Obama administration’s efforts on school lunch guidelines. However, in 2014, the group switched, leading a lobbying effort to allow schools to get exemptions.

At the time, critics and former SNA officials told The New York Times the reversal was because dozens of food companies had paid millions in sponsorship fees to help cover half of the SNA’s $10 million annual budget.

Ferraro said all of this is particularly disturbing at a time when childhood obesity is a crisis. More than 12 million children in the United States are obese, according to the Centers for Disease Control and Prevention (CDC).

Ferraro also cited a study out this week that concluded more than half of the babies in the United States aren’t getting any breast milk and many toddlers don’t eat enough vegetables and fruits.

She said this is setting up a system where children get poor nutrition in their early years and then the pattern continues when they enter school.

“We are moving backward. This is so unnecessary,” she said.

Wechsler agrees.

“Not complying with nutrition standards that were compiled with the best science?,” he said. “Yeah, I’d say that’s a step backward.”