Another recent study is dismantling marijuana stereotypes, with researchers finding that adult-use legalization is actually associated with decreased levels of obesity despite the fact that cannabis is well-known appetite stimulator.
The study—published this month by the Journal of Health Economics—analyzed obesity data in Washington State, one of the first states to legalize recreational marijuana, from 2002-2018.
Researchers at North Dakota State University, the Center for the Study of Public Choice and Private Enterprise and the Metropolitan State University of Denver said that despite marijuana’s munchies factor and overall concerns about obesity, the relationship between legalization and excessive weight gain “remains an open and under-investigated question.”
To help fill that gap, the study set out to investigate what happened in Washington State in the years after adult-use retailers opened in 2014, compared to the rest of the country after controlling for other factors.
The experiment showed that “the opening of recreational marijuana dispensaries led to decreases in obesity rates relative to a counterfactually constructed Washington State.” Specifically, the state’s obesity rate “is an average of 5.4 percent lower than the synthetic counterfactual throughout the post-treatment period” compared to an average -0.01 percent difference in the pre-legalization years.
“Our primary experiment revealed recreational marijuana legalization, which allowed for recreational marijuana dispensaries to open, resulted [in] decreases in obesity rates for Washington State,” the authors wrote. “This is somewhat surprising given previous literature finding marijuana use is often associated with increased unhealthy food consumption and lethargy.”
While some studies may have identified that association, other researchers have similarly found that stoner stereotypes don’t hold water.
For example, one recent study challenged the idea that cannabis consumers are lazy and unmotivated, with researchers finding no difference in apathy or reward-based behavior between people who use cannabis on at least a weekly basis and non-users.
“As more states gravitate to decriminalization, expanded medicinal use, and legalized recreational use of marijuana, our findings provide important insights into contemporary drug policy,” the new obesity study says. “Providing a more robust understanding of the relationships between recreational marijuana use and obesity rates also provides insights for public health policy examining the determinants and behaviors that can increase obesity.”
“Our findings also provide insights for health economics and health policy more broadly as obesity rates continue to pose health and financial concerns across the US,” it says.
One of the key limitations of the study is that it doesn’t determine exactly why legalization seems to be linked to decreased obesity rates, and so future research should seek to identify those potential mechanisms.
“The cumulative effect on obesity depends on the of impact marijuana use on a host of factors including physical health, mental health dietary changes, physical activity, and consumption patterns,” the study authors wrote. “Ultimately, how marijuana legalization affects obesity is an empirical question that requires further investigation.”
Past research has also considered the relationship between cannabis use and weight, with one study 2018 study concluding that the average marijuana consumer actually has a slimmer waistline compared to non-users.
The following year, a study published in the International Journal of Epidemiology determined that people who use cannabis are less obese on average compared to those who don’t consume marijuana.
In a separate stereotype-busting study that was published last year, researchers found that frequent marijuana consumers are actually more likely to be physically active compared to their non-using counterparts.
In 2020, a study of older Americans found that cannabis consumers tended to do more formal exercise and engage in more physical activities than non-consumers during the course of a four-month trial.
Most people who use marijuana report that consuming before or after exercising improves the experience and aids in recovery, a 2019 study separately concluded. And those who do use cannabis to elevate their workout tend to get a healthier amount of exercise.