Cannabis Users Less Likely to Be Overweight or Obese

A study found that despite the common trait of experiencing the famous "munchies" (increased appetite) after using cannabis as an adult, users tend to weigh less and are less likely to be obese.

Research estimates that over 22 million people in the United States aged 14 and older regularly use cannabis and that more and more adults and seniors are adopting the habit. 

Cannabis: Adult Use and Medical Use 

The majority of adults in the US who consume marijuana regularly represent 90% of adult users, while only the remaining 10% use it for medical purposes. 

Appetite Gain vs. Weight Gain 

One of the physiological effects of marijuana is increased appetite, or what is popularly known as the munchies. Although it may seem intuitive that increased appetite leads to weight gain, current epidemiological studies suggest that marijuana users are less likely to be obese. 

Investigating the Association 

A team of researchers from the Michigan State University (MSU) in the US decided to delve deeper into this issue, investigating whether people who regularly consume marijuana are more likely to gain weight. Omayma Alshaarawy, Ph.D., assistant professor of family medicine at MSU, led the research, which appears in the International Journal of Epidemiology. 

Alshaarawy and colleagues examined data from a prospective study called the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). 

The NESARC included 33,000 US participants aged 18 and older who completed computer-assisted interviews on cannabis use and their body mass index (BMI) between 2001 and 2005. 

Researchers applied general linear modeling to study the relationship between Body Mass Index (BMI) and marijuana use. At the end of the study period, 77% of participants had never smoked cannabis, 18% had stopped, 3% were just starting, and 2% were "persistent users". 

Marijuana Users Have Lower BMI 

The study found that overall, marijuana users were less likely to be overweight or obese. "Over a 3-year period, all participants gained weight, but interestingly, those who used marijuana had a smaller increase compared to those who never used it," reports the study's lead author. 

Alshaarawy acknowledges that the research findings may seem counterintuitive, given that marijuana increases appetite. "Our study is based on growing evidence that this opposite effect occurs," she says. 

Lower BMI Found Among New and Persistent Users 

"We found that users, even those who had just started, were more likely to have a normal and healthier weight and to stay at that weight. Only 15% of persistent users were considered obese, compared to 20% of non-users." 

The researcher further explains that although the difference in BMI between marijuana users and non-users was not very large, it is significant that researchers found this trend across the sample size. 

Does Marijuana Help You Lose Weight? 

While this study is observational and cannot infer causality, the lead researcher speculates on some mechanisms that may explain the association between lower BMI and marijuana consumption. 

"It could be something more behavioral, like someone becoming more conscious of their food intake while dealing with the munchies after using cannabis and with weight gain," she says. 

"Or it could be the cannabis itself, which may alter how certain cells, or receptors, respond in the body and may ultimately affect weight gain. More research needs to be done," the researcher concludes. 

Until more is known about the underlying mechanisms, however, Alshaarawy warns against the dangers of using marijuana to lose weight. 

"There are many health concerns surrounding cannabis that far outweigh the potential, albeit modest, positive effects it has on weight gain. People should not consider it as a way to maintain or even lose weight," she concludes.