The US Children's Advertising Review Unit (CARU) is reviewing its self-regulatory guidelines following an Institute of Medicine report criticising how food companies advertise and market products to kids.

Administered by the Council of Better Business Bureaus, CARU acknowledged its guidelines are over 30 years old and need to reflect a changing environment. The review will examine interactive online games, paid product placement in children's television and use of third-party licensed characters.

The Institute of Medicine report said ads aimed at kids push mostly high-calorie, low-nutrition food and drinks, supporting a recent lawsuit launched by the Center for Science in the Public Interest targeting the Nickelodeon TV network and Kellogg Co.

The network insists it has pushed advertisers for more balance, and Kellogg said it is proud of its contributions to healthy diets. The lawsuit seeks to stop companies from marketing junk food when 15% or more of the audience is aged eight or younger, and targets commercials, websites, giveaways, contests and other marketing activities.