Tom Hanks has been looking pretty darn good.

Peter Kramer / NBC / NBC NewsWire
And noticeably thinner...

Peter Kramer / NBC / NBC NewsWire
When Letterman asked him about his weight loss, Tom revealed that it's because he went to the doctor and found out he had Type 2 Diabetes. Here he is discussing it only as Tom Hanks would.
Watch the whole episode here.
And this is the hair we hope he's talking about:
