Excretion and perception of a characteristic odor in urine after asparagus ingestion: a psychophysical and genetic study.

The urine of people who have recently eaten asparagus has a sulfurous odor, which is distinct and similar to cooked cabbage. Using a 2-alternative forced-choice procedure, we examined individual differences in both the production of the odorants and the perception of this asparagus odor in urine. We conclude that individual differences exist in both odorant production and odor perception.

Food addiction in humans.

Most of the evidence for or against food addiction in humans focuses on similarities between food craving and drug craving. There are numerous parallels in neuroanatomy, neurochemistry, and learning. Indeed, brain mechanisms for craving probably evolved to promote seeking of natural rewards and are taken over by drugs of abuse.

Images of desire: food-craving activation during fMRI.

Food craving (defined as an intense desire to eat a specific food) is of interest because it is extremely common and because it influences obesity or nutritional status. It has also been suggested that food craving may be the evolutionary source for cravings of all kinds including cravings for drugs and alcohol. Yet, little is known about the functional neuroanatomy of food craving.