I've given up smoking a few times. I tried patches, then I tried gum, then I went cold turkey. On all three occasions I found myself sitting on the bridge of my ship, twiddling my thumbs, until I remembered that there was an essentially endless supply of biscuits at my disposal, and all of a sudden I'd replaced smoking with biscuits. The patches made me feel sick, and I inevitably threw up whatever I ate, so I didn't gain weight there, and the gum was increasing my nicotine intake by a frightening amount, and didn't kill the cravings at all, but when I quit cold turkey I put on 8kg (over a stone) in two weeks.
Since I started Vaping, I haven't felt the need to have the biscuits, so initially I lost 10kg, but now I'm putting it back on in the form of muscle, since I can go to the gym without dying in the first five minutes. Vaping has made an enormous difference to my life, and so far it's all positive. I only really have desserts when I'm eating out or on special occasions now, otherwise a nice sweet flavour gives me as much pleasure as a dessert could, and without the dietary effects.
Hope this helps.