This Is What Weed Does for Weight Loss

THE MARIJUANA STEREOTYPE doesn’t exactly scream “health.”

If you remember smoking a little too much in college, you probably also remember the midnight run to McDonald’s that inevitably followed. You probably ordered one of everything off the menu (and proceeded to mix all condiments together to put on your fries—or whatever strange flavor combination your high-self dreamt up).

Weed-induced fast food binges aren’t going to aid in weight loss—no one expects you to crave a salad or green juice when you’re high. Strange eating habits, like the kind that can surface when you’re high, typically lead to overeating, causing weight gain. Obesity adds a whole additional list of health complications to a person’s life, including heart disease, diabetes, and certain cancers.

Yet the link between cannabis and weight goes the other way, too. A 2018 meta-analysis shows a lower BMI for cannabis users than non-cannabis users. And a 2023 study from UC Irvine hinted that marijuana use in adolescence could mess with your body’s energy balance and ability to store fat. Extrapolating from a mouse study, the researchers suggest that using weed when you’re young could alter your fat cells on a molecular level, ultimately leading to a disruption in key nutrients getting to your brain and muscles.

So, exactly what is it about cannabis that might be keeping the pounds off? The answer is unclear. The 2018 meta-analysis has found that cannabis users actually consume more calories than non-users, but still have a lower BMI. Counterintuitive, to say the least. Cannabis may, though, inhibit appetite after users are done using. Cannabis causes a reduction in CB1R, a hunger receptor and thus may decrease appetite after consumption has stopped.

So, is weed the unsung weight loss tool you’re missing? Or is it a dangerous drug that will leave you raiding the fridge and sabotaging any semblance of a healthy approach to eating?

While the research on all this is still relatively new and limited, some interesting findings are coming to light.

Will Weed Help You Lose Weight?

Not directly.

“Cannabis may indirectly help with weight loss,” says Abby Langer, R.D., author of Good Food, Bad Diet, “for example, in people whose mobility increases with cannabis, or in those who switch from alcohol use to cannabis use.” Meaning, replacing alcohol with weed may lead to reduced calorie intake.

As far as cannabis-induced weight loss, some researchers speculate that weight loss may be stimulated by tetrahydrocannabinol (THC), the compound in marijuana that causes people to feel high. However this study was done on mice, not people.

Other studies on mice and rats in Poland, Italy, Hungary, Canada and the UK have also replicated these findings, leading some researchers to conclude that there is “a correlation between cannabis use and reduction in the BMI,” says Sunil Aggarwal, M.D., Ph.D., 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 using marijuana to begin with (so for instance, a cancer patient who uses marijuana as a method of pain relief).

In addition, a new study from a team of Brazilian and Iranian researchers found that cannabis and its subproducts shrank BMI and reduced body weight and weight circumference. The researchers suggest that cannabis could potentially be an adjunct in the treatment of obesity if used in a plan overseen by their doctors.

It’s important to note that cannabis isn’t a prescription for weight loss: If you don’t exercise and you have unhealthy eating habits, then weed probably won’t help you have a lower weight.

Plus, you also want to consider that smoking weed is tied to breathing problems, and can lead to chronic bronchitis even injure the cell linings of your lungs, according to the American Lung Association. Cannabis use is also linked to psychosis and mania-like symptoms in people with bipolar disorder.

Will Weed Cause You to Gain Weight?

So what about the “munchies?” The research isn’t that clear cut on whether having the munchies directly leads to weight gain or obesity. In fact, people who regularly partake in marijuana are actually less likely to be overweight or obese compared to those who don’t, according to a study in the International Journal of Epidemiology.

“The effect on [increasing] appetite is also not as straightforward as you might think,” says Brian St. Pierre, R.D., a Men’s Health nutrition advisor. “THC, the psychoactive compound that produces weed’s ‘high,’ can trigger hunger. Yet on the other hand, CBD [another compound in cannabis] seems to counteract the appetite-boosting effects of THC.”

Research has shown that marijuana may affect the mechanisms that trigger hunger in the brain, specifically receptors that release hormones. But even though there’s evidence to support the Cheetos-munching stoner stereotype, other studies have shown that marijuana use doesn’t lead to weight gain.

There is some interesting evidence that weed can indeed bother your stomach. A 2023 research review found that cannabis use is associated with a range of gastrointestinal disorders, including gastroesophageal reflux disease, pancreatitis, and peptic ulcer disease. Two cannabinoid receptors in the human body, CBR1 and CBR2, appear to interact negatively with GI function, as well as potentially affecting the sphincter and tissues in the pancreas. The review also found that cannabis can impede gastroduodenal ulcers from healing, and that chronic users of weed are more likely to end up in the hospital with complications related to peptic ulcers. If you have any GI disorder, your appetite is most likely going to suffer–leading, perhaps, to weight loss you don’t want.

The bottom line: There’s no evidence suggesting weed will help with your physique goals. The best way to lose weight is by following a healthy eating plan that works for you.