First lady Michelle ObamaMichelle LeVaughn Robinson ObamaThe Hill's 12:30 Report — Sponsored by Delta Air Lines — Frenzy over Kennedy retirement rumors | Trump challenges DOJ Obamas ink multiyear deal with Netflix Al Sharpton: Royal wedding shows white supremacy is ‘on its last breath' MORE on Tuesday will unveil a new set of proposed rules that would scale back the marketing of sugary drinks and junk food at America’s schools, during an event with Agriculture Secretary Tom Vilsack at the White House.

Under the proposed rules, companies would be limited in what products they could advertise on signs, vending machines, cups and menu boards on school grounds. According to the White House, the food industry spent nearly $150 million in 2009 on marketing in schools, with 93 percent of that money promoting the marketing of beverages.

“The idea here is simple — our classrooms should be healthy places where kids aren’t bombarded with ads for junk food,” the first lady said in a statement. “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.”

 While 38 percent of school districts already prohibit advertisements for unhealthy foods and fast food restaurants, the first lady’s initiative would expand that ban. Schools would require drink companies to promote their diet sodas or water on signs and scoreboards, rather than full-calorie options like Coca-Cola and Pepsi.

In essence, food and drink companies would not be allowed to market products to children that can’t be sold in schools. That list will become smaller after new rules, set to go into effect on July 1, that limit the sale of foods and beverages that are low in nutritional value and high in sugar and fat.

“The food marketing and local wellness standards proposed today support better health for our kids and echo the good work already taking place at home and in schools across the country," Vilsack said in a statement. "The new standards ensure that schools remain a safe place where kids can learn and where the school environment promotes healthy choices.

According to The Associated Press, the USDA will allow schools some flexibility in determining what constitutes marketing, and solicit comments on programs like Pizza Hut’s “Book It” rewards, which promise children free pizza in exchange for reading. The new rules will also not affect off-campus fundraisers, bake sales or after-school concessions.

The announcement on Tuesday comes as the first lady is crisscrossing the country to promote the fourth anniversary of her “Let’s Move” initiative designed to promote child health. Later Tuesday, she’ll travel to Miami for a separate announcement of a commitment by the Boys and Girls Club and National Parks and Recreation Association on a new initiative. Amy Poehler, star of the sitcom “Parks and Recreation,” will participate in the event.

The first lady is also participating in a blitz of media surrounding the anniversary, including an appearance last week on “The Tonight Show" Jimmy Fallon and interviews in the coming days with the “Today Show” and celebrity chef Rachel Ray.

— This post was updated at 9:44 a.m.