That's pretty much just another stereotype. When I was using regularly I more than made up for caloric intake when I came around. My lowest weight while abusing was 150. Lowest of all time was 135, and only drank during that period. I think I'm sitting at 275 currently. That's mostly due to eating, drinking, masturbating, and reddit.

If I thought my heart could take it (and felt like being around tweakers) I'd start using a bit just to get back under 200. The reality of it is not so much what I've abused over the years, but more so the lack of exercise. At my lowest weight I wasn't even smoking pot, but I was in a sweltering shop 11 hours a day, busting my ass. I ate, drank, and smoked cigs like a motherfucker.

I can eat, but I can also not eat. I don't get hungry. At my current weight I have to force my self to eat sometimes. I'm currently employed in a restaurant, and if I don't watch my self, it'll be nine o'clock at night without eating for 24 hours.