Marijuana users less likely to be overweight, obese

By Ana Sandoiu  

Fact checked by Gianna D’Emilio

New research finds that,
despite the common phenomenon of having “the munchies” after using
marijuana, cannabis users tend to weigh less and are less likely to be obese.
Recent surveys estimate that
over 22 million people in the United States ages 12 and above regularly use
cannabis and that more and more adults and seniors are taking up the habit.
Most of the adults who consume
marijuana regularly do so for recreational purposes. Almost 90 percent of U.S.
adult cannabis users say that they use it recreationally, while only the
remaining 10 percent use it for medical purposes.
One of the physiological
effects of marijuana is an increased appetite, or what is popularly referred to
as having the munchies.
Although it may seem intuitive
that an increased appetite would lead to weight gain, current existing
epidemiological studies suggest that marijuana users are less likely to be
So, a team of researchers from
Michigan State University (MSU), in East Lansing, set out to investigate this
matter further, investigating whether people who regularly consume marijuana
are more likely to gain weight.
Omayma Alshaarawy, Ph.D., an
assistant professor of family medicine at MSU, led the new research, which
appears in the International Journal of Epidemiology.

Studying cannabis use and

Alshaarawy and colleagues
examined data from a prospective study called the National Epidemiologic Survey
on Alcohol and Related Conditions (NESARC).
NESARC included 33,000 U.S.
participants ages 18 and older who completed computer-assisted interviews about
their cannabis use and their body mass index (BMI) between 2001 and 2005.
The researchers applied
general linear modeling to study the relationship between BMI and marijuana
By the end of the NESARC study
period, 77% of the study participants had never smoked cannabis, 18% had quit,
3% were just starting, and 2% were “persistent users.”
Marijuana users have lower BMI

The current study found that
overall, marijuana users were less likely to be overweight or have obesity.
“Over a 3-year period,
all participants showed a weight increase, but interestingly, those who used
marijuana had less of an increase, compared to those that never used,”
reports the study’s lead author.
Alshaarawy acknowledges that
the results of the study may seem counterintuitive, given that marijuana
increases appetite. “Our study builds on mounting evidence that this
opposite effect occurs,” she says.
Lower BMI was found among both
new and persistent users.
“We found that users,
even those who just started, were more likely to be at a normal, healthier
weight and stay at that weight. […] Only 15% of persistent users were
considered obese, compared to 20% of nonusers.”
Omayma Alshaarawy, Ph.D.

The researcher goes on to
explain that, while the difference in BMI between marijuana users and nonusers
wasn’t very big, it is significant that the researchers found this trend among
the entire sample size.
“An average 2-pound difference
doesn’t seem like much, but we found it in more than 30,000 people with all
different kinds of behaviors and still got this result,” says Alshaarawy.
Does marijuana help you lose

Although this study is
observational and cannot infer causality, the lead investigator ventures some
opinions as to the mechanisms that may explain the association between a lower
BMI and marijuana consumption.
“It could be something
that’s more behavioral, like someone becoming more conscious of their food intake
as they worry about the munchies after cannabis use and gaining weight,”
she says.
“Or it could be the
cannabis use itself, which can modify how certain cells, or receptors, respond
in the body and can ultimately affect weight gain. More research needs to be
done,” concludes the researcher.
Until we know more about the
underlying mechanisms, however, Alshaarawy warns against the dangers of using
marijuana to lose weight.
“There [are] too many
health concerns around cannabis that far outweigh the potential positive, yet
modest, effects it has on weight gain. […] People shouldn’t consider it as a
way to maintain or even lose weight.”
-Omayma Alshaarawy, Ph.D.

Kayode Ojo
Kayode Emmanuel Ojo is the Co-Founder and Managing Director at SHEFFA Limited. He is presently studying Computer Science at the National Open University, Victoria Island, Lagos.