Where does the term munchies come from?

The term cravings comes from the famous 1971 study by Charles T. Tart, “On Being Stoned,” in which researchers observed 150 marijuana users and observed their cravings for sweets. This effect of THC has to do with the underlying reason why the chemical affects the human brain so powerfully in the first place. THC, probably produced by the marijuana plant as a self-defense against herbivores, who may feel disoriented after eating the plant and avoiding it in the future, enters the receptors that are part of the brain's natural endocannabinoid system, helping to control emotions, memory, pain sensitivity and appetite.

Our brains usually produce their own chemicals (called cannabinoids) that fit into these same receptors, so by mimicking their activity, THC can dramatically alter the same factors artificially. This new finding is likely to be just one piece of the THC and appetite puzzle. Previous research has found that the drug also acts on receptors in a region of the brain called the nucleus accumbens, increasing the release of the neurotransmitter dopamine and the sense of pleasure that occurs as a result of eating while high. Other studies have found that THC also interacts with the same types of receptors in the hypothalamus, causing the release of the hormone ghrelin, which stimulates hunger.

A person who has cravings after smoking cannabis often eats much more than they would normally eat, often junk food, and often feels that their actions are uncontrollable. In the case of medical marijuana, which is used to stimulate appetite in patients, it is essentially the cravings that take effect. Having a “case of cravings” today just means that you're hungry and looking for something to snack on. Cravings are a widely used slang term that applies to the sudden onset of hunger or the need for a snack.

In addition, these mice did not show an increase in appetite when they were given the drug, which shows that the effect of craving also depended on the activity of the olfactory lobe. While the term cravings is used broadly in many different situations today, its origins lie in the culture of cannabis, where smoking certain varieties of marijuana are said to cause cravings in consumers.