Does weed make you lose weight? How one study sparked the debate
A study published in 2019 found lower rates of obesity in those who smoke marijuana.
However, the authors of the study said that the link did not mean a causal relationship and weed shouldn’t be used as a weight-loss tool.
Marijuana is used at least once a month by 8.4% of Americans aged 15 to 64. Of these, 37% use cannabis for medical reasons.
While smoking weed is often associated with an increased appetite, i.e. the “munchies,” a study in 2019 sparked the question: Could smoking marijuana help people lose weight and combat the negative health effects of obesity? Here’s what you need to know about weed and weight loss.
Using marijuana does not directly cause weight loss
A three-year study published in the October 2019 issue of the International Journal of Epidemiology indicated lower rates of obesity, on average, in those who smoke marijuana.
However, the authors of the study cautioned that weed should not be relied upon as a weight loss aid as their study did not indicate a clear causal relationship between marijuana and weight loss. To find out more about the science behind weed and weight loss, Insider spoke to Jordan Tishler, a medical doctor, an Instructor of Medicine at Harvard Medical School.
Regarding the October 2019 study’s results, Tishler says “Clearly, this is not proof of anything, but is interesting.” He adds that, “there are no studies on using cannabis to cause weight loss.”
In fact, there are only five FDA-approved substances that have been scientifically proven to directly cause people to lose weight beyond basic calorie-restriction, and marijuana is not one of them.
Evidence that marijuana can even indirectly lead to weight loss is weak. “There is one cannabinoid, which is relatively rare, called THCV that does seem, in rodents, to decrease appetite. However, this has not been shown in humans,” says Tishler.
Cannabis may cause you to eat more, not less
Using marijuana can cause behavioral changes, such as munchies, that can, on an individual level, lead to weight gain. The “munchies” refers to the phenomenon where people who have used cannabis experience a surge of hunger thought to be caused by the chemical THC in the drug.
And while the munchies is largely a phenomenon shown in Hollywood films and known simply through personal experience, there is some scientific research to indicate that marijuana can, indeed, increase appetite and, as a result, may increase body mass in individuals who consume excess calories beyond their energy needs on any given day.
So, for some, not smoking weed may be a better choice when it comes to weight loss. “If cannabis use for you leads to munchies, and you have a tendency to satisfy those munchies with high-calorie foods, then stopping cannabis may be necessary,” says Tishler.
And if you can’t stop because you’re using marijuana for a medical issue, then Tishler recommends making sure you have plenty of healthy foods around for when the munchies hit. Fruits, vegetables and lean proteins, like chicken, fish, and yogurt, are more satiating options than the stereotypical junk foods often used in these scenarios.
“I always tell my patients that if they have a bag of Doritos, they will eat it. If, on the other hand, they only have access to carrots, they’ll eat those instead. Hence, buy carrots, not Doritos,” says Tishler.
A study published in 2019 found lower rates of obesity in people who smoked weed. But that doesn't mean weed makes you lose weight. Here's why.
The Truth About Losing Weight With Weed
I was never much of a weed smoker, but when I moved to L.A., the local post-legalization zeitgeist rubbed off on me, and I began smoking several times a week. Since I’m a pretty healthy eater and don’t really crave sweets or junk food, I was a bit concerned to find that when I smoked, my stomach suddenly became a bottomless pit that only powdered donuts (and sometimes macadamia nut cookies) could fill. Even so, I didn’t gain weight — I actually lost a bit.
It seemed almost too good to be true, but others have noticed the same. Danielle Simone Brand, a 40-year-old writer in Boise, Idaho, lost 10 pounds after she started using cannabis daily. “One possible reason is that I enjoy food so much when using cannabis that I find myself savoring bites and going for quality and not necessarily quantity,” she said.
There’s a tenuous connection between weed and weight loss
Research suggests that experiences like mine and Brand’s might not be unusual. One 2019 study of 33,000 Americans in the International Journal of Epidemiology found that cannabis users weighed two pounds less than non-users on average, and were overall less likely to be overweight or obese.
Still, this study doesn’t necessarily mean weed makes you lose weight or doesn’t make you gain weight, said Jordan Tishler, a former ER doctor and current cannabis specialist on the medical advisory board at cannabisMD. Maybe stoners eat less than they think, or maybe they’re genetically less prone to weight gain, he explained.
There could be other habits smokers have that account for their lower weight. One 33-year-old engineer in Silicon Valley, who wishes to remain anonymous for professional reasons, said he lost weight when he started smoking because it decreased his desire to drink alcohol. While Tishler doesn’t know of any data proving this connection, he has also had patients who drank less after they started using cannabis.
“There are hypotheses that there might be something in cannabis that increases metabolic rate, which would decrease the weight gain,” Tishler said. “There have been some suggestions that cannabis could help protect against diabetes and excessive blood lipids [which are connected to excessive weight]. However, these are just observations that may be accounted for by many other explanations and have not been studied enough to draw any reasonable conclusions.”
Could weed actually cause weight gain?
Even if stoners are lighter on average, that doesn’t mean you can smoke as much as you want without gaining weight, said Marina Yuabova, family nurse practitioner and Assistant Professor at the City University of New York, pointing out that in the aforementioned study, in a sub-group of people who smoked weed occasionally but didn’t smoke cigarettes, the heavier the cannabis use, the heavier the people. So, even though smokers were thinner overall, it depended on how much they smoked. “When cannabis is used over a long time, it will influence weight gain due to munchies and cravings for sweets and salty snacks,” she suggested.
Joan Conklin, a 32-year-old writer in New York City, can attest to this. “Using cannabis made me gain weight because I got the munchies and I was lazy,” she said. “I got so much enjoyment out of music and reading and just existing that I didn’t get out of the apartment much.”
Jason, a 36-year-old teacher in the UK, gained around 30 pounds over two years after he started smoking. “For me, it increased unhealthy diet decisions,” he said. Meanwhile some people specifically use weed to gain weight, pointed out June Chin, a doctor on the medical advisory board at cannabisMD. So there’s really no consensus about what kind of effect weed has on weight.
There might be a biological purpose for the munchies
Regardless of weed’s impact on weight, it’s possible that the munchies serve a purpose, said James Giordano, professor of neurology and biochemistry at Georgetown University Medical Center. Cannabinoids can suppress your appetite, he explained—to put it scientifically, it causes changes in the neurotransmitters dopamine and serotonin, as well as appetite-regulating hormones like leptin and ghrelin, which may make you less hungry and more easily satisfied.
So, the munchies often show up not right as you get stoned but after some time. “When most people are stoned, they’re not eating,” Giordano said. “As they start to come out, they get a rebound in appetite.” Often, people will crave high-fat meals when they have the munchies because they need the calories, he said.
But Tishler disagrees with this characterization, saying that cannabis does not suppress appetite, and the munchies can set in during the acute intoxication phase.
Ok, regardless: How do you prevent weight gain from weed munchies?
If you’ve eaten an edible, you’re less likely to get the munchies for obvious reasons: you’ve already taken in some calories, so your body releases leptin, which suppresses your appetite, said Giordano. If you want to avoid the munchies, then an edible may be the way to go—it not only will fill you up but also will have a more prolonged appetite-suppressant effect because it’s metabolized more slowly.
But beware that regardless of your method of ingestion, it is absolutely possible to gain weight from the munchies, Tishler said. “Calories are calories. If your intake exceeds your metabolic expenditure, you will store that energy as fat,” he said. “Even if cannabis is somehow mildly protective against weight gain—again, this is entirely unproven—it can certainly be overwhelmed by high calorie intake.”
If you’re concerned about gaining weight from the munchies, Tishler recommends avoiding high-calorie cannabis products like brownies, which are about 250 calories on average. And if you get the munchies, try to satisfy them with nutritious, lower-calorie foods. Your discipline may not be at its highest when you’re stoned, so you may want to have foods you’ll feel good about eating available before you get high. “If you have Doritos in the house, likely you’ll eat them,” he said. “If you don’t and have baby carrots, you’ll eat those instead. Plan to have abundant healthy, crunchy snacks on hand, and be sure you do not have the option for making less-good choices while under the influence.”
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The relationship between cannabis, snacking, and weight is complicated.