What you are asking me is if you will replace a habit with another habit.
Remembering we are 100% solution oriented, I would answer your inquiry with another, seeking a resolution to your question rather than merely an answer. Is smoking harming your body more than putting on 20 pounds would (1 in 5 people die from causes that may be directly linked to smoking, 1 in 7 from complication from being obese)? Will you remain a non-smoker if you gain 5 pounds? If you answered no to either of these questions you are not ready to give up smoking. You are setting yourself up for failure by imparting a secondary gain on your smoking. “If I continue to smoke, I will not gain weight.” But is that really true?
How much did you weigh when you began smoking? How much do you weigh now? Are you currently at you ideal weight?
If, however, you answered yes to my first two questions then I would tell you that, no, you will not replace a habit with another habit any more than a child would crave snacks because he stopped sucking his thumb.
Habit formation in adults begins with actions we are aware of. Only through purposeful repetition does an action become a habit. You chose your habits, they don’t chose you.