Schools have already been updating their snack offerings, thanks to a 2013 USDA initiative to overhaul lunches. Vending machines now must offer snacks lower in fat, sodium, and calories. Beverage companies have also reduced the number of full-calorie products in schools by 90% between 2004 and the 2009-2010 school year, according to research published in the American Journal of Public Health last year. But simply shifting the balance of healthy offerings is not enough. Research has shown that marketing junk food to kids is insidious and has a real negative effect on children’s health. First Lady Michelle Obama, as part of her “Let’s Move” campaign to fight obesity, aims to crack down on just that. ”Our classrooms should be healthy places where kids aren’t bombarded with ads for junk food,” Obama 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.” The move follows a White House Summit on Food Marketing to Children this past fall, which brought health and industry experts to the table. The Federal Trade Commission keeps a close eye on food marketing and ads aimed at children, which should not be deceptive or false, and the Children’s Advertising Review Unit of the Beverage Business Bureau provides companies with protocols for marketing to kids. Many companies have volunteered to follow guidelines, but research shows there are still ways around the rules and kids are still seeing too much fast food advertising. A 2013 study showed that between 2009 and 2010, 99% of fast food ads that aired on children’s TV channels like Cartoon Network and Nickelodeon came from McDonald’s and Burger King. Not only that, but 70% included toy giveaways with references to child-friendly movies. A 2010 study from Yale University’s Rudd Center for Food Policy & Obesity looked at fast food advertising and reported that kids were still seeing lots of ads for junk food, and that 40% of parents reported that their child asked to go to McDonald’s at least once a week. Even more concerning was that 84% of these parents said they brought their 2-to-11-year-old kids to a fast food restaurant within the prior week. Children are vulnerable to forming long-lasting emotional connections to brands, especially when items like toys and familiar characters are involved, according to research from the Berkeley Media Studies Group. Since this deep connection made at a young age makes a one more likely to become a lifelong customer, such attachments can also be passed on to these children’s children. The American Academy of Pediatrics advises limited TV for young people, not just because it keeps them sedentary, but because it exposes them to junk food marketing that encourages poor eating habits that can have lasting impacts, like obesity. Thankfully, some companies are willing to make major changes, like Disney, which promised to drop junk food advertising on all its TV channels, websites, and radio programs by 2015. Big companies like Coca-Cola and PepsiCo are also on board with the new “Let’s Go” regulations, the latest in efforts that will hopefully pave the way for a leaner and healthier generation. This article was written by Alexandra Sifferlin and originally appeared on Time.com.