First off, hello I choose life! Second off, I first didn't worry about any weight gain. Smoking does speed up metabolism, because our lungs have to work harder to oxygenate our bodies. So when we quit smoking, our metabolisms slow down. The average former smoker gains 9-10 lbs. But there's good news, too. You can be overweight and healthy. It's just not likely that you can be obese and healthy. You also would have to put on about 70 lbs to put the same amount of stress on your body that smoking does. I put on 10 lbs when I quit. After the first year, I went to work getting it off. Once you quit smoking, you can do anything. Over the past year, I've lost 70 lbs. For the most part, smoking did not make me fat; it made me gain some weight. However, not being able to breathe made it nearly impossible to take off the weight because I couldn't exercise at full capacity. So as I have aged and my metabolism has naturally slowed down, smoking keeps me fat. To some things up: (1) There is no safe level at which to smoke, but there is a safe level at which to be overweight. (2) Smoking rarely makes people fat, but in the long run it stops people from losing weight. I don't know how old you are, but you may find smoking to be a weight handicap at some point.