Q: I quit smoking in January, and since then have gained over 20 pounds. Is this because I have also started menopause and my body is changing, or because I've quit smoking and my metabolism has changed_ Is it possible to lose the weight_ -- Carmen Arredondo, Clovis, NM.

A: Menopause by itself does not cause weight gain, although some women become less active after menopause, and the mood swings that commonly occur may lead to increased eating. It is more likely the weight gain is lated to quitting smoking.

It is unfortunate that stopping smoking is associated with weight gain, since the health benefits of stopping are so clear and compelling. It is interesting that the nicotine in cigarette smoke stimulates some of the same receptors in our brains that respond to phentermine and the fenfluramines, the components of the weight-loss medicines that were recently withdrawn from the market because of cardiac side effects. There are so many different chemicals in cigarettes, however, and the effects of just one, nicotine, on our organs are so complex that we may never know exactly why smokers gain weight when they quit. It has been estimated that quitting smoking reduces your body's metabolic rate by about 10 percent.

You have probably spent the last 25 years developing your eating habits as a smoker. When you quit, you continue to eat in accordance with those old habits, but you will be even more hungry, since hunger is a big part of nicotine withdrawal.

Despite the withdrawal symptoms, the health benefits of quitting are overwhelming. So how can you cope with the weight_ There are several things you can do. Talk to your doctor about your menopause. Are you experiencing mood swings and turning to food to feel calmer_ If menopause is having this effect on you, taking the herb black cohosh to regulate hormones may even out your mood and enable you to resist hunger better.

Try to set up a diet with the help of your doctor, a nutritionist, or one of the commercial weight-loss programs, and stick to it. Remember that if that figure I mentioned about the decrease in your metabolic rate is correct, you would have to reduce your caloric intake by about 10 percent just to stay even. Losing the pounds you have already gained will require even more.

Increase your level of aerobic exercise as much as you can. Aerobic exercise has to be intense enough to cause you to puff and sweat. Jogging, speed walking, jumping rope, aerobics classes and even yoga are all cheap ways to exercise. If you can afford it and want to exercise with others, join a club. Work exercise into your daily tasks or work day. Ride your bike on errands instead of taking the car. Use the stairs instead of the elevator for short trips of up to five flights or so. Get a push lawnmower (remember those_) and retire the gasoline one: It's just adding to pollution and global warming anyway.

Analyze your daily life: You'll probably find lots of ways to do things in a way that requires more exertion, and you'll be amazed at how much better the exercise will leave you feeling once you get over the initial sore muscles. Above all, don't even consider going back on cigarettes to lose weight.