Specifically, states will be able to grant exemptions to schools experiencing hardship in meeting the 100% whole-grain-rich standard although, even with the changes, at least half of the grains offered in schools must be whole grains.Schools will no longer need to hit the strictest target (PDF) for lowering sodium in foods offered to students. And meal programs will be able to serve students 1% flavored milk instead of fat-free flavored milk.

What kids are willing to eat

The National School Lunch Program and the School Breakfast Program are federally assisted meal programs that provide nutritionally balanced lunches for children each school day. Both programs are administered by the Department of Agriculture, though local schools set the prices for meals, offering a sliding scale to students based on family income, as required by federal regulations.

In 2012, under the Healthy Hunger-Free Kids Act (PDF), former Agriculture Secretary Tom Vilsack and first lady Michelle Obama established new standards to raise the overall nutritional requirements for school meals. It's not the only program championed by Michelle Obama that saw changes this week: The Trump administration also discontinued Let Girls Learn, an education initiative for teen girls in developing countries that started in 2015.

Perdue said in a news release that Monday's proclamation 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." According to USDA figures, school food requirements cost school districts and states an additional $1.22 billion in fiscal year 2015, but most states reported a decrease in student participation in the school lunch program.

2013-14 school year report (PDF) sponsored by the USDA found that over 60% of school food authorities observed more waste in terms of salad/raw vegetables and cooked vegetables after implementation of the updated standards.

Perdue said that when kids don't eat, they don't get the nutrition they need, and this undermines "the intent of the program."

"A perfect example is in the South, where the schools want to serve grits," said Perdue, who worked as a veterinarian before serving as a Georgia state senator and governor. "But the whole grain variety has little black flakes in it, and the kids won't eat it. The school is compliant with the whole grain requirements, but no one is eating the grits."

Marlene Schwartz, director of the Rudd Center for Food Policy and Obesity at the University of Connecticut, said the argument that food is ending up in the trash "is not supported by the research. There have been studies, ours included, that have found plate waste has not increased."

"What I've studied is whether or not children are eating the lunches, and we found that they are," Schwartz said. "I think what people don't understand about plate waste is if kids are eating, let's say 70% of the fruits and vegetables that they're taking, that means 30% of those are getting thrown away."

Naturally, the volume of waste goes up when fruits and vegetables are added to every plate, she says, but consumption of this important food group has increased as well.

Perdue's proclamation, Schwartz believes, is "slowing down the progress but not completely undoing what's been done."

"My impression has been that the food companies and the school service professionals have been working extremely hard for the last five years to try and improve things and meet these standards," she said.

"The reformulations have been done, is my point. The companies that sell pizza crusts and buns or other grain products to schools, many of them have already reformulated, so they're whole-grain-rich."

Many changes are likely to continue. Although they might allow flexibility for local school districts, Perdue's adjustments to the nutritional requirements also take pressure off the food industry, Schwartz suggests.

"There's not that much that individual food service directors can do to change the sodium in the foods they serve, because they're getting them from companies," she said. "So I feel like this is more of a gift to companies to give them more time to make those changes."

The impact on children's diets

Schwartz believes the impact on an individual child's diet will be small and amount to a slightly higher intake of saturated fat due to the higher fat content in flavored milk.

"But it's not a big jump. It's pretty small," she said. With regard to whole grains and sodium, she believes any gains made in the past will hold with no further improvements made.

"If this really helps, you know, food service directors have more flexibility and stay in the program and continue working towards improving the quality of the food they're serving, then that's OK with me," Schwartz said.

Dr. Tanya Altmann , a California pediatrician and spokeswoman for the American Academy of Pediatrics, said children get a third to half of their daily calories at school.

"So school lunch programs are critical for helping a child reach their nutrient goals throughout the day," she wrote in an email. "I'm fine with 1-percent (fat), flavored milk since all milk has important protein, calcium and (vitamin) D that growing kids need."

When it comes to loosening standards that regulate salt, which "has no nutrition benefit and can contribute to unhealthy diet as a whole," and those regulating grains, Altmann is a little less "fine."

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"We already know that kids don't eat enough whole grains," she said. "Whole grains are important for growth and development, and I think that all of the grains kids eat should be whole grains whenever possible."

A new USDA report on the nutritional quality, cost and acceptability of school meals as well as student diets will become available by 2018.

"It will be important to assess how much difference these changes make," Schwartz said. "It could have been a whole lot worse from a nutrition standpoint."