Clinical studies and survey data in healthy populations have shown a strong relationship between marijuana use and increased eating. Marijuana is reported to increase food enjoyment and the number of times individuals eat per day. Mechanistic studies of marijuana on taste and satiety have shown that it does not affect taste or produce a collapse of normal satiety mechanisms. Food intake associated with marijuana use is influenced by the social setting.

There are no controlled studies of marijuana in the AIDS-wasting syndrome, nor have there been any systematic studies of the effects of smoked marijuana on immunological status in HIV-infected patients. Smoking (tobacco, marijuana, or crack cocaine) has been shown to increase the risk of developing bacterial pneumonia in HIV-positive immune-compromised patients. Dronabinol has been shown to increase appetite and produce weight gain in AIDS and cancer patients, although the weight gain is not in lean body mass. Dronabinol is approved for the treatment of anorexia in patients with AIDS-associated weight loss.