First lady Michelle Obama and Food Network chef Rachel Ray discuss lunches with students from the Eastside and Northside Elementary Schools in Clinton, Miss., on Feb. 27, 2013. (Rogelio V. Solis/AP)

For the first time, the federal government plans to regulate how food is marketed in public schools, part of first lady Michelle Obama’s efforts to reduce the allure of unhealthy foods to the nation’s children.

The White House and the Agriculture Department on Tuesday proposed marketing regulations that would ban in-school advertising for foods that are high in sugar, fat and salt and do not meet new federal nutrition rules for foods served in the country’s 100,000 public schools.

“The idea here is simple: Our classrooms should be healthy places where kids aren’t bombarded with ads for junk food,” said Obama, who announced the proposal with Agriculture Secretary Tom Vilsack at the White House. “Because when parents are working hard to teach their kids healthy habits at home, their work shouldn’t be undone by unhealthy messages at school.”

The first lady, who this week is marking the fourth anniversary of her “Let’s Move!” campaign to reduce childhood obesity, has spoken in the past about her own struggles to reduce the junk food consumed by her daughters, Malia and Sasha.

The proposal would affect all kinds of advertising that has become ubiquitous in schools — plastered across scoreboards, vending machines, posters and even cups in the cafeteria.

Health and Human Services Secretary Kathleen Sebelius, FDA Commissioner Margaret Hamburg and first lady Michelle Obama unveil new plans for nutrition labels at the White House on Thursday. (Sarah Parnass/The Washington Post)

More than 90 percent of that advertising is for soda, sports drinks and other beverages, according to the Federal Trade Commission. Food companies spent $150 million marketing to children in schools in 2009, according to the FTC.

“Basically, this means no junk-food marketing in schools,” said Margo Wootan, nutrition policy director at Center for Science in the Public Interest, which supports the ban. “Addressing food marketing is so important because it’s so pervasive. It helps define for kids what they want to eat and even what they think of as food.”

Currently, there is food and beverage advertising in 70 percent of elementary schools and middle schools and 90 percent of high schools.

Noelle Ellerson, of the School Superintendents Association, said the proposed regulations are redundant.

“When you look at the shift in schools over the past 10 years, you don’t see huge Coca-Cola billboards going up on football fields anymore,” Ellerson said. “The market is already correcting itself. We just question the proper role of the federal government. Do we need a regulation here?”

Under the proposal, schools could still allow marketing for beverages and foods that meet nutritional standards, such as 100 percent fruit juice, low-fat milk and water.

One gray area is what to do about marketing for food-related events held off campus, such as a fast-food outlet holding a fundraising night for a school, or programs such as Pizza Hut’s “Book It,” which gives free pizza to elementary students who meet reading goals.

The government is seeking public comment about how to handle that kind of advertising and on the proposed rule itself for 60 days, after which it will issue a final rule. Observers expect the new regulations to take effect by the 2015-16 school year.

The American Beverage Association — which represents the Coca-Cola Co., the Dr Pepper Snapple Group and PepsiCo., among others — supports the changes. In a statement, the association called them “common-sense efforts.”

It also said that the industry already has been replacing sugary drinks with healthier alternatives.

Schools don’t earn much revenue from advertising, according to a 2012 study by Public Citizen. It found that less than 1 percent of schools that participated in commercial advertising earned more than $50,000 and that two-thirds of schools that had advertising received no income.

The proposed rules about marketing come on the heels of a new federal law requiring public schools to improve the nutritional content of school meals starting this school year.

A second requirement of the 2010 Healthy, Hunger-Free Kids Act also raises nutritional standards for food sold in schools but away from the lunch line — snacks and drinks in vending machines, school stores and fundraisers. Those items will have to meet calorie, fat, sodium and sugar limits and one of the following requirements: be a whole-grain-rich product; have as the main ingredient a fruit, a vegetable, a dairy product or a protein; be a combination of food that contains at least one-quarter of a cup of fruits or vegetables; or contain 10 percent of the “Daily Value” of such nutrients as calcium, Vitamin D or dietary fiber. Those changes will take effect in July. Some school districts have said they worry they will lose revenue because of the changes in what can be sold in vending machines and school stores.

As part of the marketing regulation proposal, the Obama administration has announced guidance for school wellness policies, which state a school’s goals for student nutrition and physical activity and map strategies to achieve them. The guidance requires schools to involve parents in setting the policies and calls for periodic assessments to measure progress.

And starting in July, the USDA said it will provide free breakfast and lunch to all students in schools where at least 40 percent of the children are low-income. The move is designed to increase participation in the free meals program and to relieve the paperwork burden on schools and is expected to affect 22,000 schools nationwide, officials said.