Quitting Smoking Means Gaining Weight, But Why?

If you quit smoking, you often gain weight. Researchers have now investigated in twins how big the difference is and whether this is also due to genes. They come to an unequivocal conclusion.

Weight gain is one of the great fears of smokers who want to stop smoking. In fact, most ex-smokers gain three to four kilos in the first few days. Studies also show that smokers weigh, on average, less than former smokers. For some, this prospect is reason enough to continue smoking.

But is the combination of cigarettes and weight all about nicotine? Or is there another explanation? To find out, a group of researchers led by Maarit Piirtola from the University of Helsinki (1) now investigated twin siblings, including those who differed significantly in their smoking behavior. Her conclusion: genes and common environmental factors cannot explain it to a sufficient degree.

The connection between cigarettes and weight is not always clear. Smokers do not necessarily gain as much weight as when they smoked before. And not every smoker gains weight when he/she stops smoking; some even lose it. In addition, genes play a role in both weight and smoking. There is even a study in which the same genetic variable was associated with a low BMI in smokers, but with a higher BMI in non-smokers (2).

The researchers, therefore, believe that people who smoke might differ from non-smokers not only in their BMI and health behavior but also in their genotype, i.e. their genetic make-up and certain influences from their environment. In order to find evidence for this hypothesis, the researchers evaluated the international CODACTwins database. The database contains information on smoking behavior and the BMI of almost 157,000 twins from 1960 to 2012.

As expected, smokers had a lower BMI than non-smokers. Also, former smokers weighed more than smokers. These results were regardless of gender. The correlation also applied to both men and women. On the other hand, smokers do not have to worry too much. When comparing twin siblings, one of whom had smoked and quit and the other of whom had never smoked, there was hardly any difference in weight. The work of the scientists also coincides with the results of two other studies in which former smokers only gained as much weight as they were at the level of non-smoking twin siblings (3,4). According to the authors, this information could moderately invalidate the concerns of smokers who wish to quit.

And what do the researchers say about gene involvement? The researchers found no evidence for this. The common environment of the twin siblings is also said not to have played a role. So maybe it is the nicotine itself. Nicotine reduces the feeling of hunger in the brain. A reward system could also play a role. Without cigarettes, many former smokers look for something else, especially at first, that can give them the pleasant feeling of a reward. Not infrequently, these are sweets.

There is also discussion as to whether smokers’ bodies are more energy-wasting. Some small studies suggest that smokers consume about 200 kilocalories more per day than non-smokers. So far, however, the findings are rather contradictory.

The study of these researchers also has weaknesses and limitations. The data on smoking and BMI, for example, comes from the participants themselves. There was also no information on the health status of the participants, although diseases can have a significant influence on BMI and smoking behavior.

This is part 40 of a series covering twin health provided by Paul Enck from the Tübingen University Hospital and science writer Nicole Simon. Further studies in twin research can be found at the TwinHealth website. Translation was done with the assistance of DeepL translator.

Speak Your Mind!

READ THIS NEXT

The Search For Novel Inexpensive And Efficient Non-Noble Catalysts

In the past few decades, the rapid consumption of non-renewable fossil fuels has caused significant environmental and social problems on […]

The COACH Program: Closing The “Evidence-Practice Gap” In The Prevention Of Cardiovascular Disease

Reducing coronary risk factors and taking recommended medications is crucial to retard the disease process in cardiovascular disease (CVD) in […]

Magic Mushrooms Can Chemically ‘Reset’ A Depressed Brain

There are many different kinds of mental illnesses that plague the human condition. Some are from physical problems, like genetics, […]

The Response Of Polar Clouds To The Atmospheric Electric Field And Inputs Of Ionospheric And Extraterrestrial Origin

Background The search for links between variations in extraterrestrial energy inputs to the Earth’s atmosphere and meteorological processes has a […]

Word Learning In Older Children And Adults: When Does Specialization Occur?

By the time you reach adulthood, you are estimated to know as many as 60,000 words. Despite this, vocabulary learning […]

Protein Structures And The Nature Of Life

Our major aim in the scoring project was to update the next generation about the plasticity of protein structures in […]

Intriguing Flexible Devices Based On Mechanoluminescence

Mechanoluminescence (ML), also called triboluminescence (TL), refers to the phenomenon/process that materials could emit light under mechanical stimuli, e.g., friction, […]