The Science Behind Marijuana's Magical Effect on Our Appetites
By Dario Sabaghi
“Munchies” is probably one of the most common terms in the lexicon of marijuana smokers—and naturally so; it’s one of the most pronounced effects of marijuana on our bodies after getting high.
The munchies experience has been portrayed in countless movies, and recounted in tales from smokers across all walks of life sharing their most unusual munchy cravings. Many of these stories have become etched into stoner culture, and both food brands and retail outlets use the term “munchies” to signify the strong cravings for food.
But why does marijuana give us the munchies? The explanation lies in THC, which as we all know, is the primary compound in cannabis responsible for its psychoactive effects.
The primary reason behind marijuana triggering the munchies is its interaction with the endocannabinoid system. Specifically, THC partially binds to and activates the cannabinoid receptor type 1 (CB1) of the endocannabinoid system, leading to an increase in appetite.
How does this work, exactly? Let’s dive in.
CB1 receptors, central to the mechanism behind the munchies phenomenon, function with subtle distinctions across diverse body tissues, collectively fostering an augmented appetite.
For instance, CB1 receptors can be found in the basal ganglia, a forebrain system that integrates cortical information to coordinate motor activity regulating signals, and can amplify the pleasure derived from eating, possibly intensifying the overall experience of consuming food.
That was a lot of ‘sciency’ terminology, so let’s make it a bit more digestible.
Think of CB1 receptors like the volume knobs on a stereo system located in the brain’s control room. This control room, called the basal ganglia, takes in all the information from different parts of the brain to help you move smoothly. When you eat something tasty, these volume knobs can crank up the “pleasure tunes,” making the entire experience of eating even more enjoyable.
CB1 receptors may also enhance food’s palatability through the limbic forebrain1, where it is present, rendering it more appealing and satisfying.
CB1 receptors are also present in the stomach and small intestine. In these areas, their influence ties into the regulation of ghrelin, an appetite-stimulating hormone that not only augments the desire to eat, but also accelerates the process of digestion.
CB1 receptors are also located within the hypothalamus and rhombencephalon, crucial areas of our brain that play a central role in observing and managing food intake. This suggests that activating CB1 receptors in these regions might potentially result in heightened cravings and greater food consumption.
CB1 receptors influence our appetite through various mechanisms. First, they can reduce a hormone called peptide tyrosine tyrosine (PYY), which stimulates a satiety response, and increase ghrelin. CB1 receptors activate a pathway known as mTOR (mammalian target of rapamycin), which also raises ghrelin levels and thus increases our appetite.
There are additional CB1 receptors that interact with a group of neurons called proopiomelanocortin neurons (POMCs). These neurons have a two-fold role: They can either lessen our feelings of hunger (main pathway) or enhance our appetite (secondary pathway) to varying degrees.
As illustrated, there isn’t one clear answer to the question this article hopes to answer, but an array of them—an entourage, if you will. The causes are legion. The simple explanation is this: The activation of CB1 receptors, prompted by THC in cannabis, ignites a series of effects that collectively contribute to an intensified craving for food.
Another relevant factor that plays a significant role in getting the munchies is the ability of THC to increase dopamine levels. Dopamine, a neurotransmitter associated with pleasure in the body, is released when we engage in activities we enjoy—like eating delicious food. The presence of dopamine amplifies the internal gratification we feel when eating something salty, sweet, or highly satisfying. Hence THC’s impact on the dopamine system amplifies the allure of food’s taste and aroma.
How we use cannabis can also impact the overall munchies experience. The THC content can influence the intensity of these cravings in the strain; strains with higher THC levels tend to result in a stronger appetite.
Contrary to what you may think, the munchies effect doesn’t necessarily lead to greater wait gain. This depends on the type and quantity of food you eat. Be wise in what you consume and you should be fine; polish off a five-pound box of Cheez-its while binging on old Family Guy episodes and you might find your waistline expanding.
Gaining weight could be beneficial for various health conditions, and THC can play a role in that. For instance, an HIV patient could clearly benefit from THC’s appetite boost. Cancer patients too; cannabis may help ease the pain associated with chemotherapy while simultaneously increasing appetite.
But within marijuana, there is also the potential to suppress appetite. This effect can be attributed to delta-9-tetrahydrocannabivarin (THCV), often referred to as “diet weed.” Some studies have demonstrated that cannabidiol (CBD) can contribute to appetite suppression as well, while others suggest the opposite. Both cannabinoids require further research in this area to more definitively understand their influence on how and what we consume.
There are several methods to manage marijuana munchies. For instance, choosing marijuana strains with appetite-suppressing cannabinoids, like THCV or CBD, can help reduce your “hunger attack.” Eliminating junk food in favor of healthier options, such as vegetables, and staying hydrated can also aid in managing your appetite. Other techniques may include engaging in distracting activities when you are high, such as exercising or going out.
The impact of marijuana consumption on weight gain is still under scrutiny. Recent studies suggest that, overall, marijuana users are less likely to be overweight, although the precise cause remains uncertain. It’s possible that specific cannabinoid compounds in marijuana affect metabolism contrary to popular belief, or users might adjust their behavior to counterbalance additional calories. This behavioral adjustment could involve heightened awareness of food intake due to concerns about post-cannabis-use munchies. Alternatively, cannabis itself could modify how certain cells or receptors respond in the body, influencing weight gain.
Whatever the truth turns out to be, researchers emphasize that marijuana should not be viewed as a weight loss aid.
1The limbic forebrain is the part of the brain that manages your emotions, memories, and basic survival instincts like hunger and thirst. It’s key to how you feel and react.