New Research Dispels Myth That Cigarettes Make Teenage Girls Thinner, But Smoking May Stunt Growth Of Teenage Boys

New research from the Université de Montréal, funded by the Canadian Cancer Society, shows that teenage girls who smoke cigarettes are no more likely to lose weight than girls who don’t smoke, dispelling a commonly-held belief.

In addition, boys who smoke cigarettes show a decrease in height as well as body mass index (BMI). These findings could have important public health implications, especially since many young girls cite weight control—or the desire to be runway model thin—as a reason for taking up smoking.

The findings, published online in the journal Annals of Epidemiology, are based on data collected from the Nicotine Dependence in Teens study (NDIT). Researchers collected detailed information every three months, over a five-year period, from 1,293 Montreal teens between the ages of 12 and 17.

The research team, led by researcher Dr. Jennifer O’Loughlin at the Université de Montréal, measured the teens’ height, weight, and tricep skinfold thickness. They also gathered information on many other variables, such as levels of physical activity, dietary habits, and teens’ worry about weight.

The study shows that a boy who smokes 10 cigarettes a day from age 12 to 17 will be about an inch shorter than a boy who does not smoke at all. “We were surprised to find that there was no link between smoking and weight among teen girls because it’s something that many of us take for granted,” said Dr. O’Loughlin. “We can only hope that girls will think twice about taking up smoking now, if weight loss is one of their goals.”

Dr. O’Loughlin said teenage boys’ growth may be stunted by smoking because they generally reach puberty later than girls, and are therefore more likely to still be growing when they start smoking. “Maybe teenage boys will see smoking as a bad decision if they dream of being a quarterback or star basketball player,” said Dr. O’Loughlin.

Dr. Barbara Whylie, CEO of the Canadian Cancer Society, says: “This study has enormous potential to prevent teenagers from taking up smoking and has tremendous implications for public health and tobacco control messaging. We are very proud to have funded such a worthwhile project.”