Obesity and lack of physical fitness in 10 Southern states present a difficulty for the Army in finding recruits there, and pose a risk to national security, according to a new study.

The Army recruits a large portion of its soldiers from the South, but they aren’t as fit as recruits from other regions, says the study led by researchers at The Citadel, a military college in South Carolina.

Obesity and lack of physical fitness in the South are a threat to “military readiness and national security,” researchers said in the study, which was released Wednesday and published in the Journal of Public Health Management & Practice.

Many states in the southern U.S. are already recognized for their disproportionate burden on public health due to high rates of obesity, physical inactivity and chronic disease, according to researchers.

Recruits from Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Texas were found to be significantly less fit and more likely to become injured than recruits from other states, the researchers found.

There were up to 28 percent more injuries in the least fit states compared to the “most fit” states in the U.S., they said.

The South is home to a proportionately large segment of recruits. In 2013, for example, 44 percent of all military recruits came from the South, though it has 34 percent of the country’s 18- to 24-year-old civilians, according to Defense Department data.

The researchers recommend that “active living” policies be promoted as a matter of national security, especially among lawmakers, to put more emphasis on improving the health of the population.

The study was released by The Citadel in collaboration with the U.S. Army Public Health Center and the American Heart Association, according to the college’s website.