WASHINGTON – The chairman of a key congressional panel is demanding that McDonald’s, Coca-Cola, General Mills, Kraft Foods and PepsiCo, follow Kellogg’s lead and commit to kids’ marketing limits – or else.

As part of a lawsuit settlement last week, Kellogg announced it would market only foods that meet new nutritional criteria in any medium that has a large audience of children under age 12. Kellogg also pledged to alter product ingredients to meet minimum health standards or quit advertising them to children.

Rep. Ed Markey (D-MA), chairman of the House Energy and Commerce Telecommunications and the Internet Subcommittee, sent letters to those companies asking them to implement similar limits, and said he will hold a House hearing on the issue. AdAge.com reports that Markey said his panel’s hearing on the impact of violent and tobacco-smoking images children see on TV will now also look at repercussions of the food ads children view. The letters ask the companies to respond by June 29.

”I am concerned that the prevalence of advertisements on children’s television for junk food, fast food and other foods wholly lacking in nutritional value is one of the root causes of America’s childhood obesity epidemic,” he wrote in the letters.

An aide to the congressman said the five companies were selected because of their extensive use of marketing to kids.