Widely known for causing the munchies, marijuana may also have obesity-fighting powers, according to a newly released study.

A team of researchers led by San Diego State University economist Joseph Sabia examined public-health surveys nationwide from 1990 through 2012 and found that in states where medicinal marijuana laws have been enacted, obesity rates are 2 percent to 6 percent lower than expected.

It’s a counter-intuitive finding given that cannabis’ reputation is more Cheetos than celery where weight gain is concerned. Past studies have shown that marijuana can be an effective appetite stimulant for HIV and cancer patients whose diseases come with a significant risk of weight loss that can lead to muscle wasting.

But the SDSU study, performed with Cornell University in New York, found that among younger adults, marijuana use can supplant alcohol consumption in states allowing marijuana for medicinal uses. For older adults, use of the drug can lead to greater mobility.


Increases in movement and a decrease in calorie-heavy alcohol use add up to moderate decreases in obesity rates, Sabia and his team concluded.

San Diego State University economist Joseph Sabia led a research team that looked at the relationship between medicinal marijuana and obesity rates. / photo by K.C. Alfred * U-T

Now sit back down.

It’s not time to head out to the closest marijuana dispensary for a weight-loss prescription. Sabia said the observed effects have to do with the public-health effects of marijuana policy on large populations of people. The health surveys his team used to make its estimates do not directly measure marijuana use among individuals, so it’s a little early to imagine a cannabis-fueled version of Jenny Craig.


“We are certainly not arguing that medical marijuana laws are a central tool in the fight against obesity. We are arguing that there is an unintended health benefit of these laws in that regard,” Sabia said.

The new study is perhaps the first to examine how medical marijuana laws affect public-health issues such as body weight, physical wellness and exercise. It comes at a time when many states are are trying to identify and understand the social and health impacts of marijuana legalization, which has now been enacted, in one form or another, in 23 states and the District of Columbia.

Brendan Saloner, an assistant professor at Johns Hopkins University’s Bloomberg School of Public Health who holds a doctorate in health policy, said the findings provide a new data point in the ongoing debate over whether medical marijuana is a net public-health benefit.

And the results certainly are interesting, he added, in light of the well-known munchies factor.


“If you had asked me before reading this study which direction I would have thought the results would go, I would definitely have thought that the munchies effect would have been the bigger factor here,” Saloner said.

He was quick to add that one study is far from conclusive proof that marijuana legalization leads to reduced obesity rates. More definitive proof would require more direct evidence, he said.

“I think this is a novel and important study, and a well-done study. But we still need to zero in on people who are actually consuming cannabis through a state program and more directly measure how their health changes,” Saloner said.

Sabia and his fellow researchers, doctoral students Timothy Young at SDSU and Jeffrey Swigert at Cornell, used health surveys conducted by the Behavioral Risk Factor Surveillance System to estimate the differences between states that have or have not enacted medical marijuana laws. Established in 1985, the system interviews more than 400,000 adults each year, asking them to share a range of personal health information from body weight to exercise habits.


In order to estimate how marijuana use affected body mass index, the researchers built “synthetic” statistical profiles, sampling data from the non-legalization states that most closely resembled each state where medical marijuana is legal.

In this way, by cobbling together the most applicable outcomes from states where medical marijuana is not legal, the team was able to calculate what body mass index would have been had legalization never taken place.

“We allow the data to tell us what combination of states look very similar to the treatment states,” Sabia said. “Imagine a parallel universe where we can observe what would have happened if California hadn’t legalized marijuana in 1996.”

paul.sisson@sduniontribune.com