i was on Serquel for 2+ years, i ate healthy, small meals, i went to the gym 3 - 4 times a week, i was a laborer ( i would come home dripping with sweet ) yet i STILL gained weight, not due to over eating ( i wasnt always hungry like i was on other anti psy's that i went thru before settling on Seroq )
A month after quitting Seroq, i no longer go to the gym ( doh! ) i no longer labour ( carpenter now so still physical but much much less so ) and i can literally eat bucket loads of fatty shit like MC d's, Inidian takeaway, chinese takeaway, Cafe full english fryups.. all day, every day and now i stay around the same weight, if not lose weight.. so yea, for me id say it RELAY fucked with something that creates weight gain. But now im off it, i can eat more fatty food and do less exercise and maintain a decent body mass/shape etc. with no effort.. its easier than before i ever took Seroq..
Im also generally much happier now i don't take any Anti Psy's ( altho i wouldn't recommend quitting them if you still have ANY psychotic symptoms, better to be a bit fat than permanently paranoid with multiple voices arguing with each other inside your own head, IMO anyway.. )
Anyway, it seems ( especially with Anti psy's ) each person has totally different side/longterm effects, i went through most of them before finding a tolerable one ( Seroq ) And im also entirely sure it ( combined, im sure, with the god knows how many other things iv taken in my time ) has changed not just my psychology but also psychically changed my body's workings ( metabolism deffo seems to be just one obvious example ), happens to be for the better for me, but... who knows for someone else...