"Studies have shown students may take multiple times to be exposed to something, but with those [exposures] they can…be more receptive to greater variety in the diet," said Helen Jensen, a professor of economics at Iowa State University and one of the members of the committee that wrote the new guidelines.
While nutrition advocates praised the new guidelines, some said a few steps appeared to have been left out.
Only half of fruit servings in the new guidelines can be met through juices, and half of all grains served must be whole grains.
But some say more steps could be taken.
"In keeping with the concept of the fresh fruit and vegetable program, it would serve to reinforce that, that half of these fruit and vegetable servings should be in the form of raw fruits and vegetables," said Laurie Tansman, coordinator for the Department of Clinical Nutrition's Weight Control Initiatives at the Mount Sinai Hospital in New York.
With fruits and vegetables, "At least half of the offerings should be in the raw form," she said.
Tansman expressed concern that when schools were unable to give juice, they might give apple sauce. Also, she said, she would have liked some guideline included to ensure that fruit juice and canned fruit not have any sugar added.
But overall, she said, the guidelines help combat obesity in children if they are followed. "We do a lot of talking. We need to do more action," she said.
Jensen said changing school meals could be expensive. "I think this is certainly a challenge to schools."
She noted that the Department of Agriculture (USDA) reimburses schools for some of their expenses and would be looking into the price of implementing the new plan.
"There may be some upfront costs as schools work to incorporate a greater variety of foods and meet the recommendations," said Jensen.
"Experts at the USDA are engaged in a thorough review of the IOM recommendations and will develop a proposed rule to determine the best ways to improve the national school lunch program and school breakfast program based on IOM's final report," said Agriculture Secretary Tom Vilsack in a statement released early today. "Stakeholders and the public will have ample opportunity to comment on USDA's proposed rule."
Part of what has held back school lunch programs in the past has been providing nutrition without exceeding school budgets.
"There's a saying, 'you get what you pay for,' and I think that's a very apt description of what exists for the school meal program," said Phyllis Bramson-Paul, director of the nutrition services division for the California Department of Education.
She said that the new guidelines provide a good map, including the need for equipment and training to provide better meals for students, but the onus would be on Congress to pass funding to help schools modernize their kitchens.
Overall, Bramson-Paul said the new guidelines deliver.
"We absolutely think revisions are necessary and we're thrilled to the release of this report," she said.
"We wanted to see increased attention to whole grains, more fruits and vegetables, lower fat milks. We wanted to see a maximum number of calories, and we wanted to see some sort of recognition that making these kinds of changes, which is absolutely necessary for good public health…that making these changes would cost something, and it's good to see the report recognizes that," said Bramson-Paul.