While promoting his new film Captain Phillips on The Late Show with David Letterman, actor Tom Hanks announced that he was recently diagnosed with type 2 diabetes. After years of dramatic weight gains and losses, Hanks will now adhere to a strict diet and workout regimen to treat his condition.

According to the American Diabetes Association, type 2 diabetes is caused by an insulin deficiency in the body or cellular failure to recognize insulin production. Roughly eight percent of U.S. population has been diagnosed with type 2 diabetes, making it the most common type of diabetes.

Hanks admitted that 20 years of raising and lowering his blood sugar levels may have led to him developing the condition. Failure to monitor glucose levels in the future could result in various health concerns related to diabetes.

“I went to the doctor and he said, ‘You know those high-blood-sugar numbers you’ve been dealing with since you were 36? Well, you’ve graduated. You’ve got type 2 diabetes, young man,'” Hanks told host David Letterman.

The Academy Award winner is known for his dramatic weight fluctuations while preparing for movie roles. In 1992, he gained 30 lbs. to play a 225-lb. Jimmy Dugan in A League of Their Own, only to drop 55 lbs. in 2000 to play a 170-lb. Chuck Noland in Cast Away.

"He'll have to watch what he eats very closely, he'll need to exercise regularly but there's no reason he can't live a perfectly normal life," explained Dr. Holly Phillips, CBS News medical contributor. "In dramatic weight gain and dramatic weight loss, the equilibrium of the body is just completely off. So that might predispose him to developing type 2 diabetes later."