A New Study Discovered Why Cannabis Gives You “The Munchies”

For years one of the most well-known facts about cannabis has been the extreme spike in appetite that often follows its use. Until now, it has eluded scientists as to why cannabis has this effect on us – but researchers at Washington State University set out to figure out why marijuana causes the munchies.

“We have little scientific evidence for why marijuana can stimulate appetite, but we have many states where marijuana is legal and it’s primary medicinal use is to stimulate appetite and reduce stress,” Jon Davis, Ph.D., the lead author of this study and an assistant professor at Washington State University told Inverse. “Now, I think that this new study indicates that there’s an opportunity to use science to backup the policy of using marijuana as a medicinal drug.”

Their study was conducted on rats, who were dosed with cannabis vapor in controlled doses – simulating the usual form of consumption for medical marijuana patients. Prior to exposure, the rats were separated into three categories – ones who were allowed to eat “normally” (meaning they could eat at their leisure), ones who ate enough to be stuffed, and rats that were starved for 48 hours beforehand.

Surprisingly, researchers found that cannabis vapor had the same effect on the rats, regardless of how much they had – or hadn’t – eaten before the experiment began. They began to eat smaller meals, more frequently – with about a two-hour delay from exposure the rats started eating small portions every two hours or so.

Why would the rats start eating differently? Understanding this better was the reason for the study in the first place – and researchers came up with an answer.

They found that consuming cannabis triggers the release of a hunger hormone called ghrelin, which is normally released when the stomach is empty, signaling the brain to eat. However, introducing cannabis causes a surge of ghrelin that is more than normal – and to prove this, rats were given a drug to prevent the surge, which worked, showing that cannabis was triggering the surge.

“That was pretty powerful to us,” says Davis, “It showed us, okay, this is getting really close to what it would be look like for a patient who hasn’t been able to eat and lost a lot of body weight.”

With the findings of this animal study there is hope that cannabis will one day be an approved treatment for illness-induced anorexia – which is often caused by conditions like cancer and HIV/AIDS. When patients are no longer able to fight nausea and make themselves feel hungry, anecdotal evidence dating back years finds cannabis effective – and anyone who has ever consumed marijuana regularly or even occasionally can tell you “the munchies” exist. This study simply provides the scientific reasoning behind this unique effect.