Odors influence the selection of food as much as the selection of a mate. A person deprived of physical intimacy and affection will often turn to food as a source of gratification. Compulsive over-eating may be a displacement behavior, manifesting the lack of affection and sexual gratification. The hunger for sensual experience is readily displaced from one appetitive goal to another. The control of appetite is not consciously determined.
Hunger is the monitor image of appetite, the drive to get food.
Drives produce seeking behaviors, which get results. If the drive for food produces wrong results, further drives emerge to renew the opportunity to get what is needed. An automatic brain system regulates food-seeking behavior and food intake. If we move into this system toward the molecular level of function, our description will have to account for the effect of incoming food molecules on the brain. We would recognize that the systems which determine appetite and eating behavior monitor chemicals in the blood and receive information from diverse body systems about their chemical environments.