The “Munchies.” That merciless, unrelenting craving for whatever you can chow down on when you’re enjoying cannabis. It’s perhaps the most well-known and quintessential symptom of getting high. Even folks who prefer to pass rather than puff, know about the Munchies.
So virtually everyone knows about the munchies, but what about why cannabis users get them? What’s going on there?
The munchies, like most bodily phenomenon, can be attributed to a series of related chemical and biological processes.
They’ve looked at the research in an effort to determine why smoking marijuana makes you crave, well, everything in sight.
Their findings point to an interaction between the endocannabinoids released due to THC’s pyschoactivity, and the hormone leptin that your brain uses to send hunger signals.
Essentially, the munchies are a consequences of THC’s effects. When you smoke, THC activates neurotransmitters in your brain known as endocannabinoids, which regulate metabolism and activate hunger, among other things.
“Chemicals in marijuana, especially THC, activate this false sense of hunger when they interact with hormones like leptin, a main player in sending out hunger signals,” Ryan Vandrey, a behavioral pharmacologist at Johns Hopkins, told BuzzFeed. “Then you get the munchies. If you hadn’t smoked, you probably wouldn’t have gotten hungry then or eaten as much food.”
But according to ATTN: there could be other factors involved. Getting high increases our sensitivity to taste and smell, so food may just appear more appetizing to people just after smoking cannabis.
A 2014 study published in the journal Nature Neuroscience found that THC operates on receptors in the brain’s olfactory bulb, which means that smoking causes increased sensitivity to smell and taste.
Unlike the sober lab mice included in the study, those that were dosed with THC showed significantly greater interest in the bananas and almond oils that were placed before them. They continued to sniff and eat the food for much longer than those who weren’t given the cannabis supplement.
Another study discovered that THC can have the effect of making the part of your brain responsible for telling you that you’re “full” switch its signals to a chemical that stimulates appetite. In other words, cannabis tricks your brain into thinking you’re not full when you really are.
The science behind this one is a bit more complicated. Yale scientists looked at how marijuana use affected a cluster of neurons they thought was responsible for making you feel full. This cluster is known as POMC neurons, which are located in the hypothalamus.
“The team discovered that when they injected cannabinoids into mice, the drug was turning off adjacent cells that normally command the POMC neurons to slow down,” NPR reports. “At the same time, the cannabinoids activate a receptor inside the POMC neuron that causes the cell to switch from making a chemical signal telling the brain you’re full to making endorphins, a neurotransmitter that’s known to increase appetite.”
Of course these studies have their limits: they were done on mice, and reproduced in ideal lab conditions. Still, given the similarity between mice and human metabolism, these studies put some real science behind the haunting phenomenon of “The Munchies.”