(CNN) - First Lady Michelle Obama argued Tuesday that it's "unacceptable" for House Republicans to consider making major changes to the 2010 child nutrition law - a hallmark of her "Let's Move" campaign against childhood obesity.
"The last thing we can afford to do right now is play politics with our kids' health," she said. "Now is not the time to roll back everything that we have worked for. Our kids deserve so much better than that."
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The first lady made her remarks at the White House before meeting with school leaders and experts on child nutrition.
Her comments represented a rare moment for the first lady, who stays far away from public disputes with Congress.
She urged attendees at the meeting to hold Washington accountable and "let them know that we're going to follow what's going on here."
The House Appropriations Committee announced last week it plans to let cash-strapped schools opt out of the nutrition regulations via waiver. The change would come through the 2015 agriculture spending bill.
Signed into law in 2010, the nutrition bill established new requirements for the country's free or reduced-price lunch program. More than 30 million children qualify for the federally subsidized meals.
New standards included a reduction in sodium and a requirement that each student choose one fruit or vegetable in order to get the meal for free.
The law increased the reimbursement rate for school lunches as a way to help offset the higher cost of including more produce products.
Critics, however, say schools are struggling to keep up with the new rules.
"We've experienced a lot more food waste," Julia Bauscher, president-elect of the School Nutrition Association, said Tuesday on CNN's "Newsroom."
"Students will pick up what they're supposed to have at the end of the line and then immediately throw it in the garbage," she said, describing trash cans full of oranges and apples.
Bauscher said they're not advocating for a return of junk food to the school lunch line-just looser requirements on vegetables and fruits.
"We just don't want them to have to take it if they don't intend to consume it," she added.
Saying that one in three kids are obese, the first lady emphasized that "folks in Washington should be on our side."
"Moms and dads don't want their efforts undermined when they send their kids off to school," she added.