Smoking and gaining weight?

I smoked for 14 years(from 14 years old to 28) then i stoped for 4 years and gained like 30 pounds...then last year i started again, and lost the whole 30 pounds, but i don't feel so healthy and wnat to try to stop again, however i am afraid to gain all the weight back...my question is...if i stop smoking without changing any of my curent habit (not compensating with food) will i l;ikely gain weight?in other words id the cigarette itself have chemicals that makes you slim OR is it the compensating with the food that make ppl gain weight??Cause i don't want to fix a problem (the smoking) in exanche of another one (being overweight)i am finally at a healthy weight now...