Scientists from Cornell University in New York has found in their study that a gene called AZGP1 (alphazincglycoprotein1) is the reason behind the weight increase when smokers quit their fix.
AZGP1 is a gene that which makes a protein that speeds up the breakdown of fat.
When compared between the genes of smoker and non-smokers, AZGP1 is more prevalent in smokers.
It is when your exposed yourself to smoking that AZGP1 genes starts to become more active.
But however researchers are quick to retort that their study didn’t prove that smoking helps burn off fat.
So I reckon when a smoker stops smoking, AZGP1 seizes to function, thus weight gain.