He is just extremely thick set. Bone density aswell, maybe? I've met a few guys built like this, and it's ridiculous to see lol.
That's insane, he is really built for a short guy. 190 is big. Must be bone density, hard to get that big and be natural at that height... not easy at all.
He was making 154 as an adult vs Liam Smith 3 years ago. I've never seen Canelo fat so getting down from 190 to 154 seems extreme.