You know that an ongoing punchline that stoners always have the munchies? Well, it’s not totally untrue. Research shows that smoking marijuana actually does affect the mechanisms that trigger hunger in our brain: receptors in our brain trigger the release of hormones that make us feel famished, causing us to gobble up everything in sight.
But even though there’s a grain of truth to the flabby, Cheetos-munching stoner stereotype, that doesn’t mean it’s 100 percent legit. Some studies have shown that smoking pot doesn’t lead to weight gain — in fact, it might actually help you loseweight.
It’s important to note that cannabis is not a be-all, end-all prescription for weight loss: If you don’t exercise and have unhealthy eating habits, then smoking weed probably won’t help you have a lower BMI. But according to a 2011 study from the American Journal of Epidemiology, even if cannabis consumption increases appetite, “people using cannabis are less likely to be obese than people who do not use cannabis.” Other studies have also shown that many cannabis users have trimmer waistlines than non-users, as well as lower cholesterol levels. What’s more, these results have proven to be true regardless of sample size or factors like age and gender.
So why might this be the case? Researchers speculate it’s because of tetrahydrocannabinol (THC), the compound in marijuana that causes people to be “high.” To test the link between THC and weight loss, researchers at the University of Calgary examined obese mice and mice at a regular weight, both of which were given THC daily. The researchers found that while THC did not have any effect on the size of the mice who were already at a regular weight, it did cause the obese mice to lose weight. The researchers hypothesized that this was because THC caused changes in the gut microbiome that helped regulate weight loss and digestion.
Other studies in Poland, Italy, Hungary, Canada and the UK have replicated these findings, leading some researchers to conclude that there is “a correlation between cannabis use and reduction in the BMI,” said Dr. Sunil Aggarwal, a Washington-based physician and cannabis researcher. “This association holds even after controlling for other variables,” such as age, gender, or why a person is smoking marijuana to begin with (so for instance, a cancer patient who uses marijuana as a method of pain relief).
That said, there’s also some evidence indicating that marijuana’s effects on weight fluctuation are more complicated than Aggarwal would suggest. Didier Jutras-Aswad, a professor of neuroscience at University of Montreal, has studied how cannabis affects the functions of neurobiological circuits controlling appetite.
“It is known … that cannabis causes temporary increase in appetite,” which can indeed lead to weight gain, he said. Yet he conceded that “as to whether it actually causes weight gain in the long term, the available data is limited.”
Bottom line: we still have a long way still to go in terms of research. But stay tuned. Maybe one day, if you want to lose a few pounds, the advice from the Surgeon General will be: “Just Say Grow.”