I tell them its not about what you take, its about busting your ass in the weight room. which is true. people in prison eat slop but workout all day and they get built for example.. its a dumb example but you can tell them that and hopefully they will get it.
i was doing inclines and i put on 225 and this scrawny high school kid doing inclines on the bench next to me at 85 pounds goes to me "you need a spot?" i say nah i'm good. he says "but your inclining 225??!!" i say yup ... i then rip off 10 reps. then he asks me "have you always been this strong???" i tell him look you have to bust your ass everyday in the weightroom for an hour a day and eat cals, carbs, vitamins/minerals, and protein... his reaction on his face was "ugh thats sounds like too much work" i never saw the guy again. either you are gonna commit to this, or you can be like him and show up a couple times a month