President Bush said Thursday that childhood obesity is a costly problem for the country and puts stress on American families.

"One way for this nation to cope with the issue of obesity is to get people outside — whether it be through sports or hiking or conservation," Bush said while meeting with business leaders working to encourage exercise and healthy food choices through advertising.

He said first lady Laura Bush was on her way to New York to kick off Friday's "Wear Red Day" for the National Heart, Lung and Blood Institute's Red Dress Project to increase awareness that women are at risk for heart disease. Bush signed a proclamation making February American Heart Month.

"Mothers are the ones, a lot of times, who make choices for their children," the first lady said. "They make their choices on the foods they eat. They're the ones at home, many times, who encourage their children to exercise."

Earlier, the president and Mrs. Bush attended the 55th national prayer breakfast at a Washington hotel where he prayed for the safety of U.S. troops, saying: "During this time of war, we thank God that we are part of a nation that produces courageous men and women who volunteer to defend us."

In the Roosevelt Room, the president and Mrs. Bush met with executives from the food, beverage and entertainment industries to talk about improving healthy food offerings and encouraging physical fitness in their marketing and advertising campaigns.

More than 10 million school-age children in the United States — about 18 percent — are now considered overweight. The percentage of overweight children tripled among adolescents during the past 25 years, and nearly doubled for children ages 6 to 12. This increases their risk for adult heart disease and diabetes, lowers life expectancy and creates additional health care costs.

Following the meeting, Health and Human Services Secretary Mike Leavitt was to work with Roger Enrico, chairman of DreamWorks Animation SKG, and Peggy Conlon, president and chief executive officer of The Advertising Council, to launch a public awareness campaign to help prevent childhood obesity. The campaign will include ads featuring characters from the Shrek animated movies encouraging children to "Be a Player" and get up and play for an hour a day.

Representatives from General Mills, Coca-Cola North America, Univision Communications Inc., Kraft Foods Inc., Kellogg Co., PepsiCo Inc., Subway Franchisee Advertising Fund Trust, McDonalds USA and Nickelodeon Television also were at the meeting.