New government guidelines would put restrictions on television ads and marketing by the makers of sugary breakfast cereals for kids.

Only cereals low in fat, sugar and sodium would be able to be marketed to children from ages 2 to 17. The products would also have to contain specified healthy ingredients. According to reports from The Associated Press, the government is planning to propose the voluntary guidelines Thursday.

The guidelines set parameters that are stricter than many companies have set for themselves and, if the companies agree, would eliminate much of the advertising consumers see today—on television, in magazines, in stores and on the Internet—for foods that appeal to children.

If many companies sign on to the guidelines, children could see much less of the colorful cartoon characters used to advertise cereals or other gimmicks designed to draw their attention. Under the guidelines, if the companies wanted to continue that advertising, they would have to reduce unhealthy ingredients in their products.

The food industry already has been successful in reducing the number of television ads aimed at children in recent years and much of that advertising has moved to magazines, the Internet and social media. Public health advocates have argued that the industry's self-regulation is not enough and has pushed the government to set guidelines.

In 2009, Congress directed the Federal Trade Commission, Agriculture Department, Food and Drug Administration and the federal Centers for Disease Control and Prevention to develop the recommendations. The guidelines they wrote are broad, applying to almost any promotion a child might see for a food - including text messages, product placement in video games and celebrity endorsements.

In a statement to be released Thursday, the agencies said the proposal, which would be phased in over five years and would be up for public comment until the summer, is "to encourage a marketing environment that supports, rather than undermines, parents' efforts to get their children to eat more healthfully."

Specifically, the agencies recommend that companies only market foods that have a significant amount of fruits, vegetables, whole grains, low-fat milk products, fish, extra lean meat, eggs, nuts, seeds or beans. Foods that have any trans-fat, more than 1 gram of saturated fat, 13 grams of added sugars or 210 milligrams of sodium in a serving would not be eligible for marketing to children under the guidelines.

The agencies suggest the industry focus its efforts on foods that are most heavily marketed to children, including breakfast cereals, carbonated beverages, restaurant foods and snack foods.
Sen. Tom Harkin, D-Iowa, who authored the original bill asking for the guidelines, said Wednesday he is pleased with the agencies' recommendations.

"Kids are being bombarded daily with ads for unhealthy foods and it is long past time that we limit the amount of junk food advertising," he said.

It is unclear whether government pressure will be effective enough to get many companies to sign on. Some of the country's largest food companies, including McDonalds, General Mills Inc., Kellogg Co., Kraft Foods Global and PepsiCo Inc., already have joined an initiative sponsored by the Better Business Bureau to limit their marketing to children. The standards are similar but not as strict.

Scott Faber, lobbyist for the Grocery Manufacturers Association, says many companies already have reformulated foods to reduce unhealthy ingredients.

"While the outside of the box hasn't changed, what's in the inside the box has changed dramatically," he says.

The food industry's efforts to change recipes and limit advertising have come as consumers are increasingly educated and aware of what they are eating. The president's wife, Michelle Obama, also has been leading a campaign to fight childhood obesity.

Still, public health advocates say they believe a lot of work remains. Margo Wootan, director of nutrition policy at the advocacy group Center for Science in the Public Interest, says advocates hope the guidelines will make a greater impact.

"As a mom watching television with my daughter or walking through the aisles of the supermarket, it seems like nothing has changed," she says. "If companies applied these standards it would get rid of almost all junk food marketing to kids."

The Associated Press contributed to this report.