Improving nutritional value of U.S. school food programs by increasing servings of fruits, vegetables and whole grains could increase the cost of breakfast by as much as 25 percent and lunch by 9 percent, according to a report released on Tuesday.

A report from the Institute of Medicine, an arm of the National Academies, proposed updating school meal programs to meet nutritional needs and foster better eating habits, but recognized healthier, fresher ingredients would boost costs, especially at breakfast where fruit servings would increase.

It will cost a little more, Virginia Stallings, a professor at The Children's Hospital of Philadelphia and chair of the group that conducted the study, said in an interview.

But this will be a very wise investment in children's health, she added.

Most school food providers would need more government money to help pay for food, training and equipment, the report said.

The Institute of Medicine conducted the review of the country's school breakfast and lunch programs at the request of the U.S. Agriculture Department, which oversees them. School meal programs provide 40 million meals daily and more than half of students' food and nutrient intake during the school day.

Child nutrition programs, which cost about $21 billion a year, are due for reauthorization this year but Congress is not expected to approve an overhaul for some time.

Officials at the USDA are updating the nutrition and meal requirements used for school breakfast and lunch programs, and looked for recommendations from the Institute of Medicine. The framework, last updated in 1995, sets food and nutrient standards that must be met by school programs to qualify for cash reimbursements and food from the government.

The new proposal by IOM would focus on types and quantities of food rather than individual nutrient standards.

The 355-page report recommends school meals with higher nutrient targets and proposes to gradually lower sodium levels during the next 10 years. Maximum calorie levels would be capped depending on the grade level.

The proposal said schools should ensure half or more of the grains and breads they provide contain 50 percent or more whole grains.

The report also recommended increasing fruit in breakfasts to 1 cup per day for all grades and in lunches to 1 cup per day for students in grades nine-12. Vegetables should increase to 3/4 cup per day for grades K-eight, and 1 cup per day for grades nine-12, with a focus on a greater variety of vegetables.

If these recommendations are implemented schools would serve a greater amount and variety of fruits and vegetables. Currently, the amount required to be served varies depending on what type of government approved menu plan is being used.

In addition, schools that allow students to decline individual items rather than take a whole meal should require them to take at least one serving of fruits or vegetables at each meal, the report said. The meal programs currently have no such requirement.