By Diane Bartz, Washington | Thu, April 28, 2011, 3:09 PM CEST Washington (Reuters) - The U.S. government on Thursday put food companies under pressure to stop aggressive advertising of junk food to children, saying it contributes to a severe health crisis among young Americans. The administration issued proposed voluntary guidelines that would turn children's food advertising on its head by demanding that any advertised food "be a meaningful contributor to a healthy diet" and minimize ingredients that negatively impact weight and health. This could be the Obama administration's way of addressing the rising costs in healthcare by emphasizing the health of children. First Lady Michelle Obama’s "Let's Move" campaign has pushed children to exercise more and eat better. The interdepartmental working group setting these principles includes the Federal Trade Commission, the Center for Disease Control and Prevention, the Food and Drug Administration, and the U.S. Department of Agriculture. They compiled the proposal at the request of Congress. If implemented, the guidelines would mean a revolution in food advertising for children, which is now dominated by ads for salty chips and sugary cereals, drinks, and yogurt. "The FTC commissioners are aware of the significant impact the proposal would have on the current market. A significant percentage of products currently marketed to children do not meet the proposed nutrition principles. Some foods would likely require substantial reformulation," said the five FTC commissioners in a statement. While obesity has largely ceased to rise, 10.4 percent of U.S. children aged 2 to 5 are obese, 19.6 percent of 6-11 year-olds are overweight, and 18.1 percent of 12-19 year-olds are obese according to 2007-2008 CDC data. Nearly one-third of U.S. children are overweight. Children were defined as up to the age of 17, and the principles are intended to be implemented by the year 2016. "On a daily basis, children across the country are bombarded with advertisements for junk food, and it is long overdue that we set certain limits on the advertising of this unhealthy food. Armed with these guidelines, it is now my hope that companies will voluntarily adhere to them," said Senator Tom Harkin, a Democrat from Iowa and chairman of the Senate Health, Education, Labor, and Pensions Committee, in a statement. The Association of National Advertisers and the Grocery Manufacturers Association released a study on Thursday showing that television advertising to children under 12 for junk food like cookies and soft drinks had been nearly eliminated. Meanwhile, ads for fruits and vegetables had almost doubled, the groups found. "The advertising community has actively engaged in the challenge of obesity in the United States, and this study once again confirms that food and beverage industry advertising to children under 12 has significantly shifted," said Bob Liodice, ANA President. Margo Wootan of the Center for Science in the Public Interest agreed that there was improvement in food marketed to children – especially the reduction in ads for sodas. She also praised candy company Mars for stopping television ads targeted at children for cereals and some companies for cutting their sugar content. "They should get credit for making some progress in the last five or six years. But the problem is, it's not nearly enough," she said. "It's quite astonishing, given the alarming rate of childhood obesity, that the overwhelming majority of ads aimed at children are still for fast food," Wootan said her hope was that companies would either reformulate foods to make them healthier or end ads aimed at children. (Edited by Gerald E. McCormick, Bernard Orr)