Researchers followed more than 44,000 men conscripted for military service in 1969 and 1970, and found those who were overweight as young men were 64 percent more likely to have serious liver problems and liver-related deaths in the next 40 years compared to normal weight counterparts.

“Most likely, these teens already had non-alcoholic fatty liver disease (NAFLD) at the start of the study, or developed it down the road,” said lead author Dr. Hannes Hagstrom of the Center for Digestive Diseases at Karolinska Institute in Stockholm. “We know that some persons with NAFLD do develop severe liver disease.”

The researchers used national records on 44,248 Swedish men conscripted for military service, which requires a full physical exam, and tracked their health outcomes in medical registries up to 2009.

By that time, 393 men had been diagnosed with severe liver disease, including reduced liver function, cirrhosis or liver-related death. Those who were overweight as teens were at the greatest risk, even after the analysis accounted for alcohol and tobacco use, according to the report in Journal of Hepatology.