Living in the mountains may help with weight control. So says a new four-year study of overweight military personnel that found those stationed at high altitudes are less likely to progress to obesity The New York Times reports.

Past studies have shown obesity rates are four times higher in low-altitude counties than high-altitude ones, though it is unclear why.

For this six-year study, published in the Public Library of Science journal PLOS One, researchers reviewed the records of 98,009 military members with at least two years of service as they moved between assignments at high altitude (such as around Colorado Springs) and low.

After adjusting for weight at enlistment, sex, race, age, and other factors, they found that overweight people serving at high altitudes had a 41 percent lower risk of becoming obese than those serving at low altitudes.

“These results suggest that moving to high altitude would protect an overweight person from moving to obesity,” said the lead author, Jameson D. Voss, M.D., a consultant with the United States Air Force School of Aerospace Medicine.