A factor can also be the weight and height.. it would be easier to fill up and maintain a 190~195 lbs WW fighter (well now maybe 200~205 or so since MW) then it was with Reem the 6'4 at 275 lbs.
Or you know ehem.
This, a lot of gains from steroids can be maintained if you haven't fucked your body completely. Of course it is easier when you are a lot smallerReem lost some of that weight on purpose.
You don't automatically lose all your gains when you go off steroids.