Given that this is the health and fitness forum, I think SC's response was appropriate. If someone came in here and mentioned - even tangentially - something they do that seems unhealthy, there is nothing wrong with mentioning that in a reply. For example, there are constantly posts on this forum where people mention trying to "spot reduce", or describe their extreme diets, or talk about some incredibly ineffective workout routine. IMO, even if it isn't the primary focus of the thread, it is completely reasonable to try to help them out by explaining that spot reduction is a myth, that extreme diets usually fail, that there are more effective training routines, etc. If the original poster can defend their decisions, then so be it. If not, then maybe the reply will help affect a positive change. In either way, we all can learn something from it. I do understand your concern about the possibility of the post going totally off topic, but I don't think what SC is writing is that outlandish.