Could film roles have caused Tom Hanks' diabetes?

The news of Tom Hanks diagnosis of type two diabetes has led to questions over whether choices made over his 30-year acting career could have been to blame.

Hanks revealed his diagnosis while appearing on the David Letterman show, and admitted that he's been suffering from high blood sugar and other symptoms of diabetes for over two decades.

“I went to the doctor and she 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'," he joked with the veteran host.

[Tom Hanks diagnosed with type 2 diabetes]

However, changes in his size and weight thanks to appearances in films such as 'Philadelphia' and 'Castaway' may have had a bearing on matters.

Speaking on CBS News in the US, specialist Dr Holly Phillips said: “In dramatic weight gain or dramatic weight loss the equilibrium of the body is completely off so that might create pre-disposal to diabetes later.”

In 'Philadelphia', directed by Jonathan Demme, Hanks lost 26 pounds to play AIDS sufferer Andrew Beckett in 1993. He won the Oscar for Best Actor for his trouble.

Two years later, he stacked on 30 pounds to play chunky baseball manager Jimmy Dugan in 'A League of Their Own'.

But it was 'Cast Away' in 2000 that required both his most radical gain and his most radical loss.

He put on a solid 50 pounds to play podgy Chuck Noland, the systems analyst marooned on an island after his plane crashes in the Pacific.

[Jennifer Lawrence 'bullied' over weight]

Director Robert Zemeckis made the film in two stages over a period of 16 months, breaking while Hanks dropped 55 pounds in four months – by eating only vegetables and fish – and growing a huge beard to make it seem as though he had been stranded on the island.

“The hardest thing was the time,” he said at the time. “I wish I could have just taken a pill and lost all the weight but the reality was that I had to start in October knowing that we were going to go back in February.

“The idea of looking at four months of constant vigilance as far as what I ate, as well as two hours a day in the gym doing nothing but a monotonous kind of work-out, that was formidable. You have to power yourself through it almost by some sort of meditation trickery. It’s not glamorous.”

Whether such extreme processes have contributed to his diagnosis may not be known, but other actors have suffered damage to their health in their pursuit of roles.

[Jared Leto talks shocking weight loss for Dallas Buyers Club]

Best known for his yo-yo dieting is Christian Bale, who starved himself on the set of 'The Machinist', losing 62 pounds by drinking coffee, and eating apples and the occasional can of tuna, until he weighed just 120 pounds.

He had wanted to drop to 99 pounds, but producers of the film would not let him, fearing for his health. He then regained the weight plus a further 60 pounds to play Bruce Wayne in 'Batman Begins' just months later.

Jared Leto too has followed Bale's lead. The actor and singer put on 60 pounds to play Mark David Chapman, the killer of John Lennon, in the film 'Chapter 27'. He got gout for his trouble, and at one stage of the filming had to be wheeled on to the set.

He's since gone in quite the opposite direction, dropping 40 pounds to play a transsexual with AIDs in 'The Dallas Buyer's Club'.

Thanks to eating little more than steamed fish and 'lots of melon', Gary Oldman was hospitalised while on the set of Sid Vicious biopic 'Sid and Nancy'.

In Kubrick's 'Full Metal Jacket', Vincent D'Onofrio, who played Private Leonard Lawrence, beat Robert De Niro's weight-gain record for a role (set by 'Raging Bull'), putting on over 70 pounds.

But weighing 280 pounds, as he did, the physical rigour of the role caused him to damage his knee so badly, he needed reconstructive surgery.

Meanwhile, George Clooney gained a considerable amount of weight to play a CIA man in 'Syriana', but the consequences turned out to be very serious indeed, notably when he injured himself during the torture scene.

“I ate myself sick. I put on 30 pounds in 30 days, which really scared me,” he said. “We shot that scene 20 or 30 times and in one take you actually see the desk go over and my head hit it. I think that was the time it happened. I tore my spine.

"It was my own fault. I'm 44, not 34, and I was doing all the things I could do when I was 170 pounds, not 207 pounds, so that was a big difference.”

He said the pain of the injury was so agonising that he contemplated suicide.

Movie making can be a hazardous business, then. But when it starts to adversely affect your health, it has to be questioned whether it's worth it or not.