WASHINGTON - Too fat to fight? Many American children are so overweight from being fed french fries, pizza and other unhealthy foods at school lunchrooms that they cannot handle the physical rigors of being in the military, a group of retired officers say in a new report.

National security is threatened by the sharp rise in obesity rates for young people over the last 15 years, the group Mission: Readiness contends. Weight problems are now the leading medical reason that recruits are rejected, the group says, and thus jeopardize the military's ability to fill its ranks.

In a report released Tuesday, the group says that 9 million young adults, or 27 percent of all Americans ages 17 to 24, are too fat to join the military. The retired officers were on Capitol Hill advocating for passage of a wide-ranging nutrition bill that aims to make the nation's school lunches healthier.

The military group acknowledges that other things keep young adults out of the armed services, such as a criminal record or the lack of a high school diploma.

Although all branches of the military now meet or exceed recruitment goals, retired Navy Rear Adm. James Barnett Jr., a member of the officers group, says the obesity trend could affect that.

"When over a quarter of young adults are too fat to fight, we need to take notice," Barnett said. He noted that national security in the year 2030 is "absolutely dependent" on reversing child obesity rates.

Recruitment isn't the only problem posed by obesity. According to the report, the government spends tens of millions of dollars every year to train replacements for service members discharged because of weight problems.

This isn't the first time the military has gotten involved in the debate over school lunches. During World War II, military leaders had the opposite problem, reporting that many recruits were rejected because of stunted growth and inadequate nutrition. After the war, military leaders pushed Congress to establish the national school lunch program so children would grow up healthier.

The program was established in 1946, "as a measure of national security," according to the original bill language.

Today, the group is urging Congress to eliminate junk food and high-calorie beverages from schools, put more money into the school lunch program and develop new strategies that help children develop healthier habits.

The school lunch bill, currently awaiting a Senate vote, would establish healthier options for all foods in schools, including vending machine items. The legislation would spend $4.5 billion more over 10 years for nutrition programs.

The Army is already doing its part to catch the problem earlier, working with high schoolers and interested recruits to lose weight before they are eligible for service, says U.S. Army Recruiting Command's Mark Howell. He added that he had to lose 10 pounds himself before he joined the military.

"This is the future of our Army we are looking at when we talk about these 17- to 24-year-olds," Howell said. "The sad thing is a lot of them want to join but can't."