Appetite is an emotional reaction to the stimulus of an empty stomach, and hunger is the physical response. When the stomach is empty, it is shrunken, and the contracted muscles of its wall irritate the nerve endings, causing the sensation of hunger. After eating, the walls of the stomach are stretched and its nerves are soothed so that one is no longer hungry. Any food that is ingested will suffice to destroy hunger because of its mechanical action, but appetite makes some foods more appealing than others.
Appetite is also a sensory response to the desire to repeat a previously enjoyed experience. The sight, taste, smell, and even the texture of foods in the mouth are all part of remembered pleasurable experience and sometimes are the stimuli that cause one to eat after hunger is appeased.
Know the difference. Eat slowly, savoring each bite. Let your stomach tell your brain it is full and listen to that message to avoid overeating.