Cannabis vapor robustly increased food intake in both humans and rats by boosting motivation to eat and overriding the brain's normal food reward signals, independent of hunger hormones.
Neuroscientists, appetite researchers, and clinicians managing appetite disorders or cannabis side effects.
Cannabis increased food intake within 30 minutes in humans regardless of dose or gender
What the researchers found
Vaporized cannabis acutely and robustly increased energy intake in humans (within 30 minutes, regardless of dose or gender) and rats (within 60 minutes, regardless of macronutrient content, satiation, or sex). In rats, cannabis reduced the latency to eat and increased feeding bouts. Cannabis did not alter circulating appetite hormones, and the effects were mediated by central (not peripheral) CB1 receptors.
Why it matters
Despite "the munchies" being one of the most well-known effects of cannabis, the underlying mechanisms have been poorly characterized. This study identifies that cannabis increases motivation to eat rather than simply triggering hunger hormones.
The numbers in context
In humans, increased intake occurred in the first 30 minutes regardless of dose or gender. In rats, effects appeared within 60 minutes regardless of macronutrient content, satiation, or sex. Cannabis abolished preexisting macronutrient preferences in rats. No changes in circulating appetite-associated hormones were detected.
How the study worked
Translational design combining human participants exposed to cannabis vapor with snack access, and a rat model with cannabis vapor inhalation and food access. Rat experiments examined feeding bout structure, macronutrient preferences, appetite hormones, and central vs. peripheral CB1R involvement.
What this study cannot tell us
Human component characterized intake patterns but did not include the mechanistic analyses done in rats. Vaporized cannabis contains multiple compounds beyond THC. Acute effects may not reflect chronic use patterns.
How to read the evidence
Strong translational design combining human and animal data, published in PNAS. The mechanistic detail comes from the animal component.
When this study was published
2025 publication in PNAS.
The bigger picture
Understanding the mechanism behind cannabis-induced eating could have therapeutic applications for conditions like cancer cachexia and anorexia nervosa, where increasing food motivation (rather than just appetite) is the clinical challenge.
Questions still open
- Could targeted CB1R activation in the brain be used to treat appetite loss without the psychoactive effects of cannabis?
- Does chronic cannabis use lead to tolerance of the appetite-stimulating effects?
Read the original research
Cannabis produces acute hyperphagia in humans and rodents via increased reward valuation for, and motivation to, acquire food.
Proceedings of the National Academy of Sciences of the United States of America, 122(52), e2518863122
Citation
Hume, Catherine; Cuttler, Carrie; Baglot, Samantha L; Javorcikova, Lucia; McLaughlin, Ryan J; Hill, Matthew N. (2025). Cannabis produces acute hyperphagia in humans and rodents via increased reward valuation for, and motivation to, acquire food.. Proceedings of the National Academy of Sciences of the United States of America, 122(52), e2518863122. https://doi.org/10.1073/pnas.2518863122
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