If anyone wants to gain size, it's not all about roids, if you know what to eat and when to eat then anyone can increase size and strength.
It's knowing when to eat and how to supplement your diet after workouts and next day after to rest and eat accordingly, but one does have to train moderately hard and it's not balls out all of the time.
Also your mental approach has to be positive always. Eating, training resting and eating to recharge and grow all is a chain and you break one of the links then everything else suffers.