Batista was looking pretty flabby before he left to have surgery. He couldn't work out because of a torn muscle in his back, though.
Then again, Batista will be 40 this year, so he's getting up there in years (for a professional wrestler).
The same thing happened with Brock Lesnar after he won the WWE Championship.
Randy Orton used to be pretty cut, too. Then he became World Heavyweight Champ.
I guess once you become champ, you don't have anything else to prove. That's especially the case with HHH, him begin a 11 or 12 time World Champ.