Why Quitting Smoking Makes You Fat?

Over the years, smokers have noticed that when they quit, or at least attempt to, they gain a few extra pounds more times than not. Why is that? What makes the body overcompensate for the lack of smoking with eating? A study published in the June 10 issue of the online journal Science has recently found the answer, and it’s because of, you guessed it, nicotine.

The Research

While attempting to discover new drugs to treat depression, scientists accidentally found that nicotine directly affects a person’s appetite. Yann Maneur, an associate research scientist at Yale says that they were initially “not looking into feeding behavior but depression. We were trying to find new drugs to treat depression. And, as I was testing these drugs, I realized that the animals were not eating as much.” The drug that was being tested at the time, of course, was nicotine. When it enters the brain, nicotine “activates specific nicotine receptors that are located on specific neurons known to decrease feeding and increase energy expenditure when activated.”

This means that whenever there is nicotine in a person’s system, it signals the person to stop eating, and functions as an appetite suppressant.

Study leader Marina Picciotto, MD, adds that “nicotine reduced eating and body fat through receptors implicated in nicotine aversion and withdrawal rather than reward and reinforcement,” which means that suppressing the appetite via nicotine doesn’t necessarily create or increase cravings for tobacco.

Don’t Try This at Home!

Scientists are being careful about how to relay this information, though, since they may inadvertently tell people to start smoking more in order to lose weight. Since this is a very recent discovery, scientists have yet to figure out how to use it practically. A new and effective appetite suppressant drug could come about from all this, which could allow people to lose weight, or at least not gain any more when they quit smoking. Piccioto says that nicotine-based medicine that only target cells that stops eating but not trigger the need for tobacco is highly possible.

That said, though, drugs like that would still have to be developed through a very lengthy process, as the study used only mice, and not humans. Possible side effects such as increased blood pressure need to be carefully addressed first.

[box type=”important”]People also should not use this news as a device to continue smoking. Continuing to smoke in fear of gaining weight is an illogical way of thinking, as smoking is more unhealthy. Smoke not only causes cancer, but highly increases the risk for heart attack, stroke, and various other health problems.[/box]


  2. WebMD
  3. Time.com
  4. LA Times
  5. BBC News
  6. Times of India
  7. Google News

Noel Blanco

Hello, I'm Noel Blanco and I write Fitness Philippines. I have been involved in physical fitness for more than 10 years now and am currently taking up graduate studies on Exercise and Sports Science at the University of the Philippines.

5 thoughts on “Why Quitting Smoking Makes You Fat?

  • June 22, 2011 at 9:29 pm

    I can see it now. Some smokers looking for an excuse to continue this unhealthy habit will cite this study. We would not condone a drunk who points to the fact that wine is good for you, and we should not give a smoker such slack. Smoking is bad for you, period. If any one is worried about weight gain after quitting smoking, s/he should embark on a regimen of good nutrition, exercise, and stress reduction, to stay slim and weather the initial, difficult consequences of quitting.
    It may not easy, but the alternative is more scary.

  • June 15, 2011 at 2:53 am

    Thnx for the share, Nice post…!!!
    I will make people read this artile who says Quit smoking..!!!

  • June 13, 2011 at 5:42 pm

    I quit smoking and gained about 40lbs!! I do not eat that much more than I did while smoking but I think because I have entered middle age, that might have something to do with it.

  • June 13, 2011 at 8:04 am


    Thank you for the very informative post. I do smoke and recently I gained a certain disciplined control over my eating habits.

    I think it would be good if scientist can use this new discovery and create a supplement or alternative for smoking.

    In that way, we can get a dose of nicotine and the same time control our weight.

    Armand Polanski

  • June 11, 2011 at 5:35 pm

    Great info about smoking and nicotine. To avoid weight gain during quitting smoking, instead of smoking one can take nicotine chewing gums when trying to quit smoking.


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