U.S. food companies will include more messages on exercise to youth in their marketing to dispel criticism of their role in childhood obesity, industry executives and experts said.

Food company executives at the Reuters Food Summit this week said they would move beyond changes already under way to market foods with a lower sugar content or limit advertising messages to kids.

“We will continue to expand with our advertising communications about health and wellness,” said Roger Deromedi, chief executive of Kraft Foods Inc.

Kraft has already limited its advertising to children under the age of 12 to brands that fit certain nutritional criteria. Deromedi said newer campaigns would also focus on a balance between “calories in, and calories out,” expended in physical activity.

Ads for reduced sugar Kool-Aid and Capri Sun Sport drinks “are all in active situations, showing kids outside,” he said.

Public interest groups say the U.S. food industry plays a central role in the phenomenon of childhood obesity, bombarding kids with billions of dollars in advertising to promote foods loaded with sugar and fat. An estimated 15 percent of U.S. children and teens are deemed overweight  or obese .

The U.S. government has so far resisted calls to legislate against marketing to children, as the industry pledges to steer its own messages towards healthful lifestyles.

Last week, hamburger chain McDonald’s Corp. unveiled a program to promote exercise featuring Olympic gold-medal winners and new ads touting the benefits of fresh vegetables and fruit. General Mills Inc. has moved to include more whole grains in its breakfast cereals, but stopped short of curbing marketing to kids.

“People’s focus is going to be more and more on” exercise, said Tom Bernardin, chief executive of advertising agency Leo Burnett USA, part of France’s Publicis. “It’s all coming down to one thing: the need to exercise and balance out what they take in.”

Leo Burnett creates advertising for clients like McDonald’s and Kellogg Co.

“We believe advertising to kids is beneficial as part of a balanced and healthy diet,” said David Mackay, president of Kellogg. “If we can do that in the context of showing kids being active…where we actually encourage physical activity, many in the industry believe we can be part of the solution to what is a crisis.”

Mackay cited research showing children who ate a bowl of cereal for breakfast, whether sugary or not, on average had a lower body mass index (BMI) than kids who did not. But he cast doubt on whether more healthful versions of cereal would catch on at the expense of sweeter versions.

A whole-grain cereal called Tiger Power had gained a 0.2 percent to 0.3 percent market share within a few weeks of its launch, but would unlikely gain a much greater share as consumers seemed to prefer cereals like the original Frosted Flakes, he said.

“If you look at the nutritional value of that product, maybe it should be a 3 share,” Mackay said.

But advertisers and nutritional experts have a long way to go to change American eating habits, according to a food industry research expert.

“At home, what is always looked at (in terms of meals) is what is easiest,” said Harry Balzer, vice president of market research group NPD. “Health is not the primary consideration.”

While many consumers say they would like to be eating more fruits and vegetables, the cost and relative inconvenience of finding fresh produce are prohibitive, he said.

At the same time, slower growth in the number of mothers working outside the home may mean a tighter watch on what kids eat, while options of healthier food like milk and fruit at fast-food restaurants also may change eating habits for the better - rather than advertising more or different food, Balzer said