If you look at some of his videos of him in the gym working out he isn't actually that big of a dude. I think it's possible he "could" be natural. When I was in jail there was a black guy who I would have sworn was juicing but obviously couldn't have been while locked up (and I asked folks in there what he looked like when he came in and they said he was skinny and strung out when he did). Point being, some of these guys are freaks.