Marijuana can effect metabolism so depending on how and when it is used then i assume you can lose weight using marijuana.
I have never lost weight due to smoking a bit of puff and I do smoke a fair bit, Its hard to lose weight when you have the constant munchies and are eating all the time, I get the hump and sulk if I don't have at least 3 cooked meals a day, none of this half portion healthy bollocks, Im talking real food,, Bacon, eggs, bangers, chips, pie,,,,, love it. Saying that, I stay around the ''16-0 ''16-7 stone mark so I don't put much weight on either?