Ripcode, the hero Preds in P1, P2 and the upcoming AVP-R are actually pretty lean looking. Only the AVP Preds were built like football players.
The Predator costuming community is practically a complete reversal of the Star Wars costuming community (which in itself is way larger). In the Star Wars costuming clubs, most everyone is trying to match up to a movie suit, with only a small number of costumers making custom or EU characters. In the Predator costuming world, almost every costumer is making a generic member of their race, with only a few people trying to match their costumes up with a particular movie suit.