Researchers have investigated the metabolism of smokers who have stopped
smoking. They compared two groups: One group who merely stopped, and one
who took nicotine as a replacement. The nicotine group had a higher
metabolism when they exercised, but when both groups rested the difference
in metabolism was less and was under what they had when they smoked.
This is probably the reason why smokers who stop often go up a few kilo.
Anyway, it is always best to stop smoking as this is far more dangerous
for health than an increase in weight.
You ask for advice on how to avoid going up in weight when you stop
smoking and I suggest that you exercise more, e.g, walk for an hour a day
or take some other exercise which you like. Exercise helps to prevent a
weight increase in several ways. Some energy is used directly for the
exercise, some is used to build up the body so that it gets more muscles
where the metabolism is higher than in fat. Furthermore, most people feel
less hungry if they exercise in moderation every day. It seems that
exercise helps the body's natural hunger regulation system function
better. It is also often much easier to achieve a slimming objective with
daily exercise.
To stop smoking, or, to stop any other addiction, is extremely difficult.
As the body demands immediate satisfaction of its needs, it very easily
happens that one form of addiction is replaced by another. Many previous
smokers feed themselves chocolate, or any other food, as long as they can
stay off cigarettes. There is therefore a risk that a problem of
overweight will be created.