Obesity

Individuals whose fathers were obese before age 45 were more likely than those whose parents were not obese to have high levels of alanine aminotransferase (ALT) in their blood, an enzyme that signals liver injury.

High ALT levels in the general population can be associated with non-alcoholic fatty liver disease, an obesity-related condition. One severe, progressive form of non-alcoholic fatty liver disease is nonalcoholic steatohepatitis, which can lead to cirrhosis and even liver cancer.

Having a father with early-onset obesity increased a person's likelihood of having elevated ALT levels, regardless of their own weight, the researchers found. But there was no link between maternal obesity and ALT levels, and no relationship at all between parental obesity and AST levels.