Health Decoder put up a short 2.5 minute clip explaining how THC in cannabis causes the munchies. They take a few loving pot shots at weedists but the information is easy to absorb.
THC has been show to make food more pleasurable by increasing the amount of dopamine, which is our body’s way of rewarding us with pleasurable feelings, in response to eating or drinking sugar.
They also cite a 2011 Canadian study showing nearly 75% of cancer patients, who often suffer from wasting syndrome, said food tasted better with THC pills. Compare this versus just 30% of cancer patients who were given placebo pills. These are just THC pills and recent science is showing that when only a particular compound is isolated from cannabis (i.e. THC), it doesn’t always produce the same effect as if that same isolated compound was consumed with the other numerous compounds in cannabis (i.e. various terpenoids).