George's St-Pierre is retired from the UFC, and has for sure declined from his competitive best, yet no one would know that from looking at him, and he can still maintain his identity through his appearance.
Meanwhile, IFBB pro bodybuilders simply must reduce in size if they want to maintain any modicum of health or longevity. And by doing that - they lose their identity.
That may be what is driving Cutler to get bjgger by the day now, just as it did for Gary Strydom in 2006.