Some of that chub may have been a result of the bloat that certain steroids can cause in some people.
Hogan had that in the 80’s.
Remember when he went off and slimmed down around WM9? He looked good, but a lot smaller.
Then he looked fantastic when he came back for 18 - bigger & leaner – probably with better diet and better juice.
Rock doesn’t need the bulk now unless he wants to do another Scorpion King type roll, so maybe he figures it’s not worth putting his body through all of that.
He’s got good genetics and still has a good physique.
He may still be taking a little something now, but like a lot of his Hollywood buddies, maybe it’s more along the lines of GH to stay lean and maintain some decent muscle.