Satisfying the pot-induced munchies is almost as an important part of the experience as the bud itself. But despite its ability to ignite an insatiable craving for sugar and grease, researchers have been aware of the inverse relationship between cannabis use and obesity since 2010. The science reveals two seemingly inconsistent facts about cannabis’ effect on weight: cannabinoids can reduce nausea and stimulate the appetite, but the chronic use of cannabinoids may also block appetite-stimulating signaling as well as reduce obesity causing inflammation. When it comes to weight, cannabis is associated with both gain and loss depending on the frequency of use.
The Endocannabinoid System And Metabolism
- Cannabinoid Receptors, the molecular pathways including CB1 and CB2 that allow chemical compounds to send signals to the brain;
- Endocannabinoids, the chemical compounds such as anandamide that are produced by the brain and interact with cannabinoid receptors; and
- Enzymes, the catalysts that facilitate interactions between endocannabinoids and cannabinoid receptors
The ECS is responsible for regulating an array of processes including mood, sleep, appetite, pain sensation, memory, and fertility. When the ECS is performing at optimal functionality, the body is operating at homeostasis. However, when the ECS is under- or overperforming, the physiological processes it regulates exhibit abnormalities.
For example, research suggests that obesity may be, in part, a result of overactivation of the ECS. A 2007 review by Dr. Jean-Pierre Després found that the activation of the CB1 receptor by endocannabinoids like anandamide may stimulate the appetite enough to induce weight gain. Després’ also found evidence that blocking CB1 receptors may both reduce food intake and increase weight loss beyond what would be expected from decreased calorie consumption.
What does this have to do with cannabis? Cannabis contains at least 100 known cannabinoids, chemical compounds that act very much like the endocannabinoids that our brains produce. In fact, cannabis also seems to affect the ECS’ facilitation of processes related to weight gain in disparate ways: it can be an appetite stimulant but may also be linked to a reduced BMI.
Cannabis As An Appetite Stimulant
One of cannabis’ oldest therapeutic uses has been as an anti-emetic. THC and CBD, the most abundant cannabinoids in the plant, alleviate nausea and vomiting by suppressing the release of serotonin from the small intestine. Because of this effect, researchers have consistently identified cannabinoids as efficacious in the treatment of chemotherapy-induced nausea and vomiting.
In addition to mitigating the severity of appetite depressing symptoms, cannabinoids have also been identified as appetite stimulants. A 2018 Supportive Care in Cancer randomized, double-blind, placebo-controlled clinical trial determined that Nabilone, a cannabis-derived medication, was a safe and effective therapy for the treatment of cancer-induced anorexia. Participants who took it consumed more calories than those who took a placebo.
These findings seem to corroborate the culturally embedded belief that THC gives its consumers the “munchies,” or an intense craving for food. According to the authors of a 2015 Nature study, here’s how that works: cannabinoids cause neurons that normally signal satiety to signal hunger. That means that consuming cannabinoids will cause a person to eat even when they are full. The obvious ramification of this would be a trend of elevated BMI infrequent cannabis users, right? Turns out cannabis is not so obvious.
Cannabis Users Are Less Likely to be Obese
A 2019 International Journal of Epidemiology study by Dr. Omayma Alshaarawy built on pre-clinical research conducted in the past 10 years found that there is an inverse relationship between cannabis use and elevated BMI. That’s right—if you consume cannabis, the plant that tells you to eat more food than your body needs, you are less likely to be overweight or obese than if you didn’t consume cannabis at all.
The study collected data from a survey completed by almost 35,000 participants aged 18 years and older from all 50 states and the District of Columbia. Alshaarawy categorized participants based on their cannabis use with the following labels: non-users, quitters, recent initiates, and persistent users. She found that participants in all of the cannabis-using subgroups had a reduced BMI 36 months after their baseline interview. The decrease in BMI was greater in proportion to the amount of cannabis consumed, so persistent cannabis users had the greatest decrease in BMI.
Alshaarawy offered a few suggestions that would explain the perceived relationship between cannabis and weight-loss. For one, she referred to older research associating chronic cannabis use with the down-regulation of CB-1 receptors, the ECS receptors responsible for stimulating the appetite. This may be why the greatest reduction in BMI was seen in the persistent cannabis use subgroup.
She also referenced research associating inflammation with obesity as a possible explanation. This research identifies inflammation as a trigger of obesity-related insulin resistance and type 2 diabetes. Alshaarawy suggests that cannabis’ anti-inflammatory effects may contribute to the reduced BMI trends she discovered in her own research.
Don’t Count on Cannabis for Weight Loss
While this recent evidence suggests that there is an association between cannabis and a healthier weight, the limits of the research are significant. Alshaarawy noted that concluding a causal relationship between cannabis and weight loss is difficult given the study’s lack of randomization, use of self-reported data, and failure to control for variations in food intake or physical activity. Basically, Alshaarawy’s study doesn’t draw conclusions about weed’s weight-loss attributes, but it does make this suggestion: the relationship between cannabinoids and weight management should continue to be researched.
So does cannabis cause you to lose weight? Maybe. The trends identified in the research suggest that cannabis may help reduce BMI. At the same time, research also points to weed’s appetite-stimulating attributes. So if you’re looking for marijuana to be the answer to your weight question, chances are you’ll discover it plays a much smaller and more complex part than the combined efficacy of diet and exercise.