During his Monday night guest spot on “The Late Show with David Letterman,” actor Tom Hanks revealed that he’s been diagnosed with Type 2 diabetes – and that weight fluctuations for on-screen roles may have been a contributing factor.

Hanks once put on 30 pounds for his role in “A League of Their Own,” and lost 55 while playing character Chuck Nolan in “Cast Away.” Hanks explained to Letterman, “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.’”

Adult-onset diabetes is a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. It can initially be managed by altering diet and exercising, though some patients require insulin regardless of lifestyle changes. It’s a disease most commonly associated with obesity; In 1985, 30 million people had the disease. Now roughly 285 million suffer from it. Long-term complications from high blood sugar can include heart disease, strokes, diabetic retinopathy, kidney failure and poor circulation in the limbs, leading to amputations.

Hanks added, “My doctor said, ‘Look, if you can weigh as much as you weighed in high school, you will essentially be totally healthy – will not have Type 2 diabetes.’ Then I said to her, ‘Well, I’m going to have Type 2 diabetes because there is no way I can weigh as much as I did in high school.’” Hanks told Letterman he’d weighed 98 pounds during his high school days.

Hanks stars in the film “Captain Phillips,” which opens Friday. Here’s the trailer:

http://www.youtube.com/watch?v=BA6ri9Ip-Ws

In related news, celebrity chef Paula Deen has also been diagnosed with type 2 diabetes, and drug maker Nova Nordisk had “suspended” their activities with her, after the infamous racial epithet scandal.

Image via YouTube.