"The gaining and the losing of weight may have had something to do with it because you eat so much bad food and you don't take any exercise when you're heavy," he said at the London Film Festival on Wednesday.
"I've talked to a number of actors who have gained weight for roles and just out of the sheer physical toll on one's knees and shoulders, no one wants to do it again. I think that's more or less a young man's game.
The Oscar winner said he is unlikely to take on such a role again.
"I'm 57 and I don't think I'm going to take on a job, or even go on vacation again, and see to it that I can gain 30 pounds.
He also said his condition could be in part due to genetics.
"But I think I was genetically inclined to get it and I think it goes back to a lifestyle that I have been leading ever since I was seven-years-old, as supposed to 36," the Cast Away actor said ahead of the release of his new action thriller Captain Phillips.
He remained positive about his diagnosis which he revealed on David Letterman's Late Show after the TV chat show host commented on how much weight Tom had lost.
"It's not Type 1 diabetes... it's just eating right, getting exercise and taking the right kind of medicines and I feel just fine. It's part of life and I'm just fine thank you.
"Everybody's going to have some degree of health problem as we get older. I think I'm pretty good on cholesterol, I think I'm pretty good on a lot of those, it just so happens that my body type and my lifestyle gives me a preclusion for high blood sugars.
"I know what to do, I have access to good doctors, I eat good food and after that it's up to the individual."
Despite his admission that body-altering movie roles might have caused his diabetes, he resolutely said he wouldn't warn anyone off such roles.
"And I refuse, refuse, refuse, refuse to tell any of those other celebrities what to do."