quitting cigs and weight gain

[OrhanPamuk]

Hey guys,
I'm 22, 6'2", 220 lbs. I've lost 50 lbs since January from working out and eating well. I've been smoking the entire time (around 15/day), but I've decided to call it quits. I've read online that quitting smoking causes weight gain, not simply because of a change in eating habits, but because your metabolism slows down. Is this true? Do any of you have experience quitting smoking? Thanks.