School lunch standards received their first overhaul in 15 years Wednesday, as the U.S. Department of Agriculture released standards that would increase the amount of fruits, vegetables and whole grain foods served to 32 million students.

The new rules are the result of the Healthy, Hunger-Free Kids Act championed by first lady Michelle Obama, who has made reducing childhood obesity her signature issue. The new standards will affect government-subsidized meals served to low-income children, and a forthcoming set of rules will for the first time regulate non-subsidized foods like those found in school vending machines.

When we send our kids to school, we expect that they won't be eating the kind of fatty, salty, sugary foods that we try to keep them from eating at home, Obama, 48, said in a press release that accompanied her visit to a school cateferia in Alexandria, Va. We want the food they get at school to be the same kind of food we would serve at our own kitchen tables.

Under the new guidelines, which were based on recommendations issued by the National Academy of Science's health arm, schools will be required to double the amount of fruits and vegetables they serve, curtail the amount of sodium in food and limit calories by reducing portion sizes. Milk will have to be low fat, and chocolate milk will have to be non-fat.

The changes faced stiff opposition from food industry players that included potato farmers and companies that produce frozen pizzas. Congress blocked a measure that would have limited schools to serving potatoes no more than twice a week and passed a bill ensuring that the tomato paste on pizza will continue to be counted as a vegetable, although pizza will be made with healthier ingredients that include whole wheat crusts.

Conservatives in Congress denounced the measures as an example of government overreach they said was consistent with the Obama administration's push for financial reform and an overhaul of the health care system. They joined some school districts in criticizing the cost of implementing the new rules, which the Department of Agriculture said will amount to about $3.2 billion over the next five years.

The Department of Agriculture released a menu with examples of lunches under the new guidelines. A meal of a hot dog, canned pears, and raw celery and carrots would be replaced with whole wheat spaghetti and meat sauce, green beans, cauliflower, broccoli and kiwi.