Newswise — At a time when American military forces are stretched thin overseas, a growing number of potential recruits are too fat to enlist, according to an analysis by Cornell University researchers.

In the past half-century, the number of women of military age who exceed the U.S. Army’s enlistment standards for weight-to-height ratio and body fat percentage has more than tripled. For military-age men, the figure has more than doubled.

As of 2007-08, 5.7 million American men and 16.5 million women of military age were ineligible for duty because they were overweight or obese, according to John Cawley, Cornell associate professor of policy analysis and management, and a Cornell economics doctoral student Catherine Maclean.

The findings, published in September by the National Bureau of Economic Research in a working paper titled, “Unfit for Service: The Implications of Rising Obesity for U.S. Military Recruitment,” are cause for alarm for the four U.S. military branches, which together must attract more than 180,000 new service members each year.

“Almost one in four applicants to the military are rejected for being overweight or obese – it’s the most common reason for medical disqualification,” Cawley said. “It is well-known that the military is struggling to recruit and retain soldiers. Having a smaller pool of men and women who are fit enough to serve adds to the strain and creates even more problems for national defense.”

The study follows a similar report last spring by retired generals and admirals. But Cawley and Maclean chart the climbing obesity rates over a much longer period, using data from the National Health and Nutrition Examination Surveys spanning 1959-2008. Moreover, the Cornell study estimates the number of civilians who meet the body fat requirements of each military branch, which had not been tracked previously.

“It’s another example of the underappreciated public consequences of obesity,” Cawley said. “We tend to think of obesity as a personal, individual health problem. But the fact that U.S. military leaders view it as a threat to national security and military readiness shows its far-reaching impact.”

The paper is available online: http://www.nber.org/papers/w16408