Does smoking weed make you lose weight? The unexpected link between cannabis and metabolism

• A study published in 2019 found lower rates of obesity in those who smoke cannabis.
• Research has found a link between the endocannabinoid system, appetite, and metabolism.

Smoking weed is often associated with an increased appetite, i.e. the "munchies." That extra snacking is surely a precursor to weight gain, right?

One large 2019 study tells a different story.

The study indicated lower rates of obesity, on average, in those who smoke weed. This raises questions around how cannabis could play a role in combating the negative health effects of obesity.

Research looking at cannabis and its effects on appetite, weight, and metabolism is ongoing, but there appears to be a connection.

Here's what you need to know about weed and weight loss.

Does cannabis directly cause weight loss?

The 2019 study did not indicate a clear causal relationship between cannabis and weight loss. In fact, the study's authors cautioned that weed should not be relied upon as a weight loss aid.

Jordan Tishler, a medical doctor and Instructor of Medicine at Harvard Medical School, says the 2019 study doesn't prove anything, but it is interesting. "There are no studies on using cannabis to cause weight loss," he says.

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 cannabis is not one of them.

Note: The FDA has approved orlistat (Xenical, Alli), phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), liraglutide (Saxenda), and semaglutide (Wegovy) for long-term use against weight loss.

Evidence that cannabis can indirectly lead to weight loss is weak. But, there are some ways that researchers say it could influence weight loss:

• Better sleep, which leads to better metabolic health
• Better mobility due to pain relief
• Reduced calories from alcohol, for people replacing alcohol with weed

Cannabis and metabolism

As the science around cannabis continues to advance, it's becoming clearer to researchers how it may affect appetite and metabolism.

In fact, a small 2020 study of regular cannabis users found multiple blood markers related to metabolism in participants' blood after they either smoked, vaporized, or ingested cannabis vs. a placebo.

This may be because cannabis affects the endocannabinoid system, which is integral to regulating bodily functions like memory, sleep, pain, immune responses, and appetite.

THC activates a receptor in the endocannabinoid system called cannabinoid receptor type 1. Here's how researchers theorize that it affects body weight:

• An overactive receptor may promote obesity and elevated fat levels.

• Blocking this receptor may reduce body weight and fat levels, according to animal studies on obese mice.

However, while THC activates the receptor, research has found that another cannabinoid compound may have the ability to block it without causing psychoactive effects.

"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.

So, unlike THC, THCV may have appetite suppressing qualities. However, more human research is needed to draw a connection between THCV, appetite reduction, and weight loss.

Note: THCV is present in some strains of weed.

Cannabis may cause you to eat more, not less

The "munchies" is when people who have used cannabis experience a surge of hunger thought to be caused by the chemical THC in the drug.

There is scientific research to indicate that cannabis 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.

In fact, cannabis is used to boost appetite and weight gain in people who struggle to eat, such as people with HIV/AIDS or people undergoing treatment for cancer.

But there's a catch: Despite the fact that initial, or acute, THC use boosts appetite and drives eating, animal studies have found that chronic (daily or near-daily) THC use also seems to prevent weight and fat gain.

This phenomenon is also reflected in humans: While cannabis use is associated with a higher intake of calories, regular users, on average, still have lower BMIs and reduced rates of obesity.

Scientists are still trying to make sense of this juxtaposition, and more research is needed before they can draw hard conclusions.

The "munchies" issue

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.

If you're using cannabis for a medical issue, then Tishler recommends making sure you have plenty of healthy foods around for when the munchies hit.

Fruits, vegetables, whole grains, and lean proteins, like chicken, fish, and yogurt, are more satiating and healthy options than processed, high-fat junk foods.

"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.

Insider's takeaway

Smoking weed does not seem to directly cause weight loss. In fact, using weed causes a spike in appetite — the munchies — which could contribute to weight gain.

However, as scientists continue to study cannabis and the endocannabinoid system, it's becoming more apparent that it is linked to appetite, energy regulation, and metabolism.

Despite some promising findings around the endocannabinoid system and obesity, scientists still haven't made a direct link between using weed and weight loss.