I don't think he's had work done. Despite all his unhealthy living, he's always had good skin with very few wrinkles. I think it's genetic. Some people just genetically age less than others. Plus, he wears tons of makeup so you can't see wrinkles he does have. He claims to have quit smoking.
I just think he had work done as his face was massive before, and when you lose weight on your face its ages you more,..especially as I remember he had these weird lines on his cheeks when he was heavy. Also his jowls are gone, totally gone.