Tom Hanks has shocked fans revealing on US television that he suffers from Type 2 diabetes.
The 57-year-old actor revealed his diagnosis after chat show host David Letterman commented on his slim appearance.
Hanks admitted that he had been experiencing symptoms of the disease — which is the result of the body not producing enough insulin — for 20 years.
"I went to the doctors and they said, 'You know those high blood sugar numbers you've been living with since you were 36? Well, you've graduated. You've got type 2 diabetes, young man," he said.
"It's controllable through diet. My doctor said, 'If you can weight what you weighed in high school you'll essentially be completely healthy and not have type 2 diabetes.
"And I said, 'Well, I'm going to have type 2 diabetes then," he said, noting that he was a "very skinny boy".
The Oscar-winning actor regularly adjusts his weight for his roles, most notably for his role in Cast Away for which he reportedly lost 25kg, only to bulk up again for his next role. He is currently promoting his new film Captain Phillips.
The strain of diabetes from which the actor suffers is the most common form, affecting almost 90 per cent of people with diabetes.
The actor assured his fans that he could manage his condition.
"Yep, I have #2 diabetes," he tweeted.
"Type 1 is VERY SERIOUS! Type 2 I can manage with good habits. I shall!"
Hanks made light of his illness speaking about it on the TV show.
"Something going to kill us all," he said.