Getting an uncontrollable appetite then raiding the fridge is a common symptom of smoking marijuana. Now, the researchers reveal what can possibly cause the inevitable reaction to the cannabis.

For many years, it was a mystery to solve for scientists to figure out why tetrahydrocannabinol (THC), the active ingredient of pot, causes such a powerful increase in appetite. A European study has finally revealed that people get "the munchies" after using marijuana because their sense of smell and taste is heightened.

A group of neuroscientists, which was led by Giovanni Marsicano of the University of Bordeaux, did an experiment with mice and found out that THC fits into receptors in the brain's olfactory bulb -- a structure at the front of the brain involved in the perception of odors. Moreover, they claimed in a study published in Nature Neuroscience that this dramatically increases the animal's ability to smell food and led them to eat more of it.

In detail, the researchers exposed a group of mice to banana and almond oils as a test of sensitivity to scent. The mice sniffed the oils first, and then stopped showing interest. However, the mice that were given THC continued to sniff, and these THC-dosed mice also ate much more.

Afterwards, the scientists genetically engineered some mice to lack a type of cannabinoid receptor in their olfactory bulbs and subjected them to the identical experiment. The result showed that even if the mice were given THC, it had no effect, revealing the drug's scent-enhancing power involved activity in this specific area of the brain.

The group explained that by making the sense of smell and taste more acute, THC creates the same sensations felt when people are deprived of food. The scientists claim that if the findings hold true for humans, it may help better tackle obesity, as well as develop treatments for appetite disorders by changing the link between smell and appetite.