Miami Dolphins legend Dan Marino revealed in a People magazine interview that he was diagnosed with liver disease 18 years ago but is doing well after adjusting his diet and sticking to a regular exercise routine.

Marino turned 64 on the day of the interview. He said that during a routine checkup in 2007, doctors diagnosed him with nonalcoholic fatty liver disease (NAFLD).

Understanding NAFLD

According to the Mayo Clinic, nonalcoholic fatty liver disease is a liver problem that affects people who drink little to no alcohol. In NAFLD, too much fat builds up in the liver. It is most often seen in people who are overweight or obese.

According to the Mayo Clinic, NAFLD is becoming more common, particularly in Middle Eastern and Western nations, as obesity rates rise. It is the most common form of liver disease worldwide.