When people are high, they often reach for the junk food. But why? And why junk food specifically?

The munchies stem from how tetrahydrocannabinol (THC) interacts with the body’s own endocannabinoid system. 

Among many other functions, the endocannabinoid system regulates appetite. Cannabis that is consumed modifies this system in several key ways.

THC binds to cannabinoid type 1 (CB1) receptors throughout the brain. The primary suspect causing the munchies is the CB1 receptors in the hypothalamus, a brain region that is about the size of an almond. The hypothalamus has an important role in many brain-body interactions including temperature control, thirst, and, yes, hunger. THC stimulates the release of hormones that signal hunger, even when you’re physically full.

Cannabis also enhances the sense of smell and taste of certain foods by acting on receptors in the olfactory bulb — the first stop in smell processing. Brain imaging studies show increased responses to THC in areas of the brain involved in processing sensory information about food. THC also triggers dopamine release in the brain’s reward system (the so-called “hedonic highway”), making eating feel even more pleasurable and reinforcing food-seeking behavior. 

Researchers at Yale discovered that cannabis affects neurons that normally signal fullness. Under THC, these neurons instead promote hunger — so that’s a double whammy when it comes to trying to resist eating. Other studies indicate that cannabis increases production of ghrelin — often called the “hunger hormone” — which is normally released when your stomach is empty.

From an evolutionary standpoint, the munchies may have evolved as a survival mechanism, encouraging feeding when food is available. When THC enters the body, it taps into this ancient system. 

Of course, the endocannabinoid system evolved before nacho flavor came on the scene, so you can’t really blame evolution. 

It should be noted that not everyone gets the munchies equally. Factors affecting the munchy response include tolerance levels (regular users often report diminished munchies over time), the specific cannabinoid profile of the cannabis consumed (for example, CBD and tetrahydrocannabivarin, THCV, may actually suppress appetite), and individual differences in endocannabinoid system functioning.

But why junk food? People who consume THC don’t usually “go cray” for broccoli. No, they want foods with high caloric density; that is, foods that are sweet, crunchy and fat.

Brain imaging studies show that cannabis increases neural activity in reward regions when people view images of junk food versus images of regular food, suggesting junk foods become disproportionately appealing.

Under the influence of THC, the brain appears to amplify the pleasure derived from already-reinforcing experiences. For most of us, sugar, fat and salt are already reinforcing; THC amplifies these signals. Anecdotally, cannabis users report enhanced appreciation for certain food textures, whether it’s the crunch of chips, the creaminess of ice cream or the chewiness of candy. This sensory enhancement makes processed foods, which often have engineered textures, particularly satisfying.

How to mitigate the munchies

Defeating the munchies might be close to impossible, but it may be possible to moderate those primitive drives, nevertheless. CBD can counteract some of THC’s appetite-stimulating effects; therefore, choose strains with a more balanced THC:CBD ratio. As noted above, THCV may also suppress appetite. 

Beyond the particular strains you consume, some behavioral tricks may help. First, if you can, have a satisfying, protein-rich meal before using cannabis. Second, stay hydrated. Sometimes thirst masquerades as hunger. Keep water or herbal tea nearby and drink it before reaching for food. And don’t be too hard on yourself if you succumb to the munchies. Somewhat surprisingly, epidemiological studies indicate that cannabis consumption is not directly linked to weight gain; in fact, many studies suggest the opposite, with cannabis users having a lower prevalence of obesity and lower body mass index (BMI) than nonusers. 

The Cannabis Boomer is really Alex Terrazas, PhD, a psychologist and neuroscientist who hosts “The Cannabis Boomer Podcast” found on all major podcast platforms. For more information, visit cannabisboomer.com

This article appears in Aug 21-28, 2025.