Updated

The Agriculture Department will allow some schools to delay adding more whole-grains to meals this year, responding to criticism from school nutrition officials and Congress that the standards were too difficult to put in place.

The delay comes hours after a Republican-led House spending panel criticized the Obama administration's healthier school-lunch standards and proposed letting some schools opt out of them entirely.

USDA said schools can put off for two years a requirement that all pastas in schools be whole-grain rich, or more than half whole grain, if they can demonstrate that they have had "significant challenges" in preparing whole-grain pasta. Many schools have complained that the whole-grain pastas don't hold together well when cooked.

"Schools raised legitimate concerns that acceptable whole-grain rich pasta products were not available," said Kevin Concannon, USDA undersecretary for food, nutrition and consumer services. "We worked to find a solution which will allow more time for industry to develop products that will work for schools."

While many students have adapted easily to whole grain breads and rolls, which have been on the market for some time, school nutrition directors say they are having a harder time with pastas, biscuits, tortillas and grits - all popular items on the lunch line. The current requirement is that 50 percent of all grain products be whole-grain rich, but that is set to jump to 100 percent in the next school year.

The School Nutrition Association, which represents school nutrition directors and companies that sell food to schools, said the announcement is a good first step.

"Getting students to accept whole grain pasta is just one of many challenges school meal programs have faced under USDA regulations," said Leah Schmidt, president of the group.

The GOP spending bill for agriculture and food programs was released Monday and would allow schools to apply for waivers to opt out of the standards if they had a net loss on school food programs for a six month period. A House Appropriations subcommittee approved the bill Tuesday.

Championed by first lady Michelle Obama, the healthier standards have been phased in over the last two school years, with more changes coming in 2014.The first lady held a call to rally supporters Monday.

In addition to whole grain requirements, the rules set fat, calorie, sugar and sodium limits on foods in the lunch line and beyond. While many schools have had success putting the rules in place, others have said they are too restrictive and costly.

Rep. Robert Aderholt, the Alabama Republican who is chairman of the agriculture appropriations panel, said the school lunch rules have "upset the economics of the school meals program by driving the cost of the plate up while pushing participation down."

In his statement, USDA's Concannon criticized Republicans for going after the standards.

"With one third of American children fighting obesity, we cannot accept politically motivated efforts to undermine standards and deny kids healthier options," he said.

This is not the first time USDA has tweaked the standards. In 2012, just a few months after they went into effect, the department scrapped maximums on proteins and grains after students complained they were hungry.

A Senate subcommittee approved its version of the agriculture spending bill Tuesday but did not propose changes to school meals. The full Senate Appropriations Committee will consider the legislation on Thursday.

At that meeting, Sen. John Hoeven, R-N.D., is expected to offer an amendment to maintain the current requirement that only 50 percent of grains be whole-grain rich and delay upcoming sodium requirements pending scientific research.