During World War II, at least 40 percent of potential military recruits were undernourished. So after the war, military leaders helped convince Congress to pass the National School Lunch Program to make subsidized meals part of kids' nutritional curriculum.
And, maybe partly as a result, today's soldiers are an inch-and-a-half taller on average.
But now the military has the opposite problem, young people are getting too much nutrition. A growing number of potential recruits are "too fat to fight."
More than 9 million Americans of prime recruiting age are too heavy to join up, says the group, called Mission: Readiness.
"Overall only 1 in 4 of our young adults between the ages of 17 and 24 is eligible for military service," says Rear Adm. Jamie Barnett (ret.). Obesity is one of the main reasons, he says.
The proportion of recruits rejected for being overweight jumped from 12 percent in 1995 to 21 percent in 2008. Other categories for rejection include failure to graduate from high school and having a criminal record.
The group cites federal health statistics that show more than 40 percent of adults from 17 to 24 are overweight or obese in 39 states -- up from only one state a decade ago. In Kentucky, Alabama and Mississippi, more than half of young adults are too heavy, according to the definition used by the Centers for Disease Control and Prevention.
The new report says the military discharges more than 1,200 first-term enlistees each year because of weight problems. That costs the armed services about $50,000 per person -- or $60 million -- to recruit and train replacements.
The average overweight 17-to-24-year-old would have to lose 34 pounds to achieve "normal" weight, the CDC says.
Mission: Readiness unveiled its report at a Capitol Hill press conference designed to nudge Congress toward reauthorization of a school nutrition program that would restrict junk food and high-calorie beverages, improve the quality of menus, expand eligibility for free school meals, and improve nutrition education.
Last year, the National Academy of Sciences' Institute of Medicine recommended an upgrade for school meals that would limit calories and boost the amounts of fruits and vegetables served.
The Obama administration has asked for $1 billion a year in additional funding for school nutrition. The Senate version of the bill, now awaiting action, would add about half that much. The House hasn't yet acted on the issue.