Re: Why do you get the 'munchies' when you are stoned

Marijuana contains several chemicals called cannabinoids.  The best 
characterized is delta9-tetrahydrocannabinol (delta9-THC), which has 
psychoactive properties (it's what makes you feel "stoned").  Delta9-THC 
has been shown to increase food consumption in humans and laboratory 
animals (see for example REFERENCE 1 and the references therein).  This 
effect is probably dependent on the actions of delta9-THC in a part of the 
brain termed the hypothalamus, which is involved in controlling feeding 
behavior;  however, other brain regions also may be involved.   

Cannabinoids work in the body by binding to what are called cannbinoid (CB) 
"receptors".  There are endogenous compounds, one of which is called 
anandamide, in your body which bind to these receptors.  The ability of 
delta9-THC to produce the "munchies" is likely to mediated by the so-called 
CB1 receptor.  This concludion is based on the demonstration that 
anandamide induces increased food consumption by acting on CB1 receptors 
(REFERENCE 2)

One of the most promising clinical uses of the cannabinoids is as 
an appetite stimulant for AIDS and cancer patients (see REFERENCE 3, which 
is a well written review article on the medical uses of marijuana).



REFERENCES
1 Williams et al. (1998) Physiol. Biol. Behav. 65, 343-346

2  Williams and Kirkham  (1999)  Psychopharmacology  143, 315-317.

3)  Rosentahl and Kleber  (1999)  Proceedings of the Association of 
American Physicians 111, 159-165.