Often someone who has stopped smoking will rapidly gain 5 to 7 pounds and then lose it very slowly. A few will gain a greater amount when they stop smoking.
However, heavy cigarette smoking is much more harmful to health than marked obesity. Depending on your age, a pack of cigarettes a day may have statistically the same deleterious effect as 50 to 100 pounds of excess weight.
Yes. Don't let the though of gaining a little bit of weight deter you from quitting smoking. Not only does smoking put you at risk of developing cardiovascular disease, but various types of cancer as well.