But researchers hope to change all that with a new set of guidelines to promote healthier eating habits in American children and stem the rising levels of obesity. Today, the Institute of Medicine (IOM) -- part of the National Academy of Sciences -- released new guidelines in an attempt to change what schools serve for breakfast and lunch.
"What you really will see is the change in nutrient needs," said Mary Jo Tuckwell, a consultant for the food services group inTeam Associates in Ashland, Wis., and a member of the committee that wrote the guidelines. "Instead of targeting nutrients, we're really focusing on foods."
Several guidelines, as doctors have recommended for years, suggest adding more fruits, vegetables and whole grains to the menu.
But perhaps one of the biggest changes -- and one that is supported by both child nutritionists and a celebrity chef -- is an emphasis on adding new equipment and infrastructure to school kitchens to speed the changes along.
British TV chef Jamie Oliver told ABC News through a representative that the largest change schools could make to improve menus was to "teach nutrition services staff how to cook freshly prepared meals." Oliver said this would require training, better ways of storing fresh food, and in many cases adding equipment and facilities.
In early 2010, Oliver will begin starring in "Jamie Oliver's Food Revolution," a show on ABC where he will remake the school lunch menu in Huntington, W. Va. The British chef had previously embarked on a project in the United Kingdom where he remade the meals at a school there to make them healthier.
Oliver had already pushed for people to learn to cook more nutritious meals at home. Taking the issue to the schools, he said, would make a big difference.
"Children are getting diabetes, heart disease, all sorts of diseases that only used to show up in adults, because of the food they are eating," said Oliver. "We can influence this in a massive way by improving at least one daily meal, school lunch."
Researchers backed that assertion.
"One of the ways in which we can stem the tide of obesity is to change what is happening in schools," said Dr. Lori Feldman-Winter, a pediatrician specializing in adolescent medicine at Cooper University Hospital. "Once that becomes the norm, we can actually change the eating habits of kids and teens."
She said that just 10 servings of a nutritious food can lead children to change their diets.
"If you offer healthy options enough, then that becomes the preferred option and kids do incorporate healthy eating into their habits," said Winter. "That is also what they're going to choose as they get older, and they will not select items that will land them in fast food environments, for example.
"I think there is an opportunity in children to change their palate. School has taken on a role that goes beyond just education."
Authors of the guidelines said lifelong habits were among their goals.
"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.