I dunno. My sister is a heroin addict. At the start of use (first year or two) she was easily 300lbs. It wasn't until she started that slippery slope to rock bottom that she lost the weight (mom stopped letting her live in a rental for free, no car, no job, etc.). I think she's down to 110lbs at 5'6".  I don't talk to her anymore, but friends have seen her in public and say she looks like a skeleton with stretched out skin hanging off of her. Also looks about 60 according to these sources (she just turned 30). Odd thing is, she used to always say she couldn't lose the weight unless she subbed a hard drug for her food addiction; she was right.