If the Obama administration gets its way, food marketers would only advertise their healthiest products to children, possibly including teenagers who have long-been exempt from such restrictions.

The long-awaited guidelines, jointly proposed today by four federal agencies, drew an immediate rebuke from the ad industry, which called the initiative "overly restrictive" and based on "limited and outdated information."

"If companies were to comply with these proposals, the restrictions are sufficiently onerous that they would basically block a substantial amount of advertising," Dan Jaffe, exec VP-government relations for the Association of National Advertisers, told Ad Age. "How much? We still need to find out by digging deeper and talking to our companies on a one-to-one basis."

Indeed, today's announcement by the Federal Trade Commission-led Interagency Working Group on Food Marketed to Children is only an opening salvo in what will be a lengthy debate between government and industry on how to solve the growing childhood obesity crisis. For one, the guidelines would not carry the weight of law and are only recommendations on how the industry should regulate itself. Secondly, the rules will likely to change as both health advocates and companies submit comments during the next 45 days.

Although not binding, whatever emerges in the final report to Congress will likely be adhered to in some fashion because the rules are put forth by a quartet of agencies that have strong sway over marketers, including the FTC, Food and Drug Administration, Centers for Disease Control and Prevention and Department of Agriculture. "Despite calling these proposals 'voluntary,' the government clearly is trying to place major pressure on the food, beverage and restaurant industries on what can and cannot be advertised," the ANA said in a statement.

As written, the rules would start in 2016 and only allow foods that contain no trans fat and not more than one gram of saturated fat and 13 grams of added sugar per "eating occasion" to be marketed to children. Also, the foods could not contain more than 210 milligrams of sodium per serving. The sodium restrictions would tighten by 2021. In a concession to industry, the rules do not include "naturally occurring" nutrients. Additionally, the foods must provide a "meaningful contribution to a healthful diet," including from at least one major healthy food group such as fruit, vegetables, whole grain, fish, eggs and beans.

Among the biggest concerns for advertisers is the proposed expansion of the traditional definition of children in these matters from kids under age 12 to children aged 2-17, although the final rules for teenagers will likely be "narrower in scope and possibly limited to in-school marketing activities and social media, such as online social networking web sites," the FTC said in a statement. The industry remains opposed to any rules that cover teens. Said Mr. Jaffe: "Once you've gotten past 12, we believe kids are fully able to understand advertising and to deal with it."

The FTC said it "recognizes the proposal sets ambitious goals that, if adopted, would be challenging for industry to meet" and that "a significant percentage of the products currently marketed to children would not meet the proposed nutrition principles." The "childhood obesity epidemic, however, cannot be reversed without significant changes in our children's eating habits."

Industry leaders say they have long taken the issue seriously and that companies are continually setting stricter standards. Efforts are led by the 17-member Children's Food and Beverage Advertising Initiative, which includes some of the nation's largest food advertisers, including PepsiCo, Coca-Cola Co., Kraft Foods, General Mills, McDonald's, Burger King, Mars and Hershey Co.

The group "has been both changing what foods are advertised to children and improving the foods themselves," Elaine Kolish, VP of the group, which is housed under the Council of Better Business Bureaus, said in a statement. "While the product names may be the same, what's inside those advertised products has often changed considerably."

Participating companies pledge to devote child-directed advertising to "better-for-you foods," as well as establish nutrition standards governing foods marketed to kids. The companies also limit the use of "third-party licensed characters, celebrities and movie tie-ins in child-directed advertising consistent with the company's advertising commitment or to not engage in such advertising."

But health advocates say the companies have not gone far enough. "A key weakness of the current self-regulatory approach to food marketing to children is that each company has its own strategically tailored standards," Margo G. Wootan, director of nutrition policy at the Center for Science in the Public Interest, said in a statement. "While overall the standards look fairly similar, many have loopholes, like weak or no sodium standards for fast-food companies and weak sugar standards for cereal marketers."

The group is pleased with the government's proposal, calling it "strong and sensible."