The how and why of munchies

Spreading peanut butter on a block of cheese or dipping a banana in a mug of Swiss Miss sounds like five-star appetizing after hitting a bowl for a reason. 

The THC’s effect on the brain can explain the post-pot urge to rummage through kitchen cabinets for unconventional concoctions. Marijuana impairs the ability to analyze ideas, rationalize impulses and inhibit inappropriate behaviors, according to Ethan Block, a Pitt professor who teaches a course called Drugs and Behavior. 

“This can lead to taking risks and outbursts of creativity,” Block said. “Where food preparation is concerned, one tends to do strange and impulsive things that seem like an amazing idea at the time.”

The sudden craving for snacks is popularly known as the “munchies,” which Block defines as “being really hungry, but with a few twists, after smoking marijuana.” 

The drug, he said, travels through brain pathways until it hits a cannabinoid receptor. At this point, THC, the principal psychoactive chemical in marijuana, tricks the brain into perceiving hunger — and the illusory appetitite begins, according to Block.

But a simple case of the munchies is more than just an impulsive culinary concept. 

“Your body has a natural way of signaling hunger and fullness,” Bita Moghaddam, a Pitt professor and researcher of neuroscience and psychiatry, said. “There are a whole bunch of neurotransmitters and a very complicated system that regulates appetite and appetite suppression.” 

Block attributes this hunger signal to THC, which mimics the neurotransmitters that send chemical messages throughout the nervous system, affecting processes such as pleasure, memory, thinking, concentration, movement, coordination and sensory perception. 

“THC works like these natural brain chemicals, except in a bigger dose,” Block said. “THC activates the part of the brain that controls hunger, and it also affects the way we think and feel.” 

In addition to activating the pathways that control hunger, marijuana stimulates the part of the brain that controls repetitive behavior, the “basal ganglia circuitry,” which is a network of nerves in the brain, according to a study published in the Neuroscience and Biobehavioral Reviews Journal.

“One can sort of get stuck in the repetitive act of grabbing Cheetos, crunching Cheetos and swallowing Cheetos until all of the Cheetos are gone,” Block said. 

This reptitive eating process has triggered the false belief that people crave certain types of foods to satisfy their “munchie” desire, according to Moghaddam.

The only consistent impact that marijuana has on users is “enhanced appetite,” Moghaddam said, but food choices are usually based on personal preference connected to genetic structure.

“There’s a huge individual variability when it comes to drug taking behavior. The same goes with appetite, food processes and appetite suppression,” Moghaddam said.

People may reach for sugary and fatty foods, Block added, because carbs and sugar quickly refuel the body. 

Despite the excessive desire to consume unhealthy foods, the “munchies” have some benefits as well. 

A 2010 study in the Current Treatment Options in Oncology journal titled “Cancer Cachexia: Traditional Therapies and Novel Molecular Mechanism-Based Approaches to Treatment,” suggested that marijuana is an effective way to counteract the loss of appetite that comes with chemotherapy. 

Medical practitioners can apply the same idea to achieve an opposite effect. Rimonabant, an anti-obesity drug, acts on the same cannabinoid receptor in the mind but serves an appetite suppressant, according to David Volk, a Pitt psychiatry professor and researcher.

“Rimonabant was studied as an anti-obesity drug, an appetite suppressant,” Volk said. “But it was withdrawn from the market due to harmful side effects.” 

Volk’s research focuses on the relationship between marijuana and schizophrenia, but he was not able to comment on the relationship between marijuana and appetite further.

The only way to prevent excessive eating, Block said, is to “purge” the cabinet of anything that one would eat on impulse.  

Yet, even then, a snack-happy smoker might still get in touch with his or her creative culinary side.

“Even if you purge all the decent snacks and all you have is a jar of pickles and a few stale Red Vines, you’re probably gonna go ahead and dip the Red Vines in that pickle juice,” Block said.