For instance, one study published in 2014 in Nature Neuroscience found that your brain's CB1 receptors are a key part of the equation. These are activated both by chemicals your body makes naturally and compounds found in marijuana (cannabinoids). The researchers in this study found that CB1 receptors are surprisingly crucial for your ability to smell. Therefore, the researchers suggest that any effect pot has on our hunger could be a direct results of CB1 receptors heightening our sense of smell. After all, that pizza's a lot harder to resist once those cheesy, carb-filled fumes start wafting their way through your apartment.