I actually know someone who does not relish eating ' which I can't fathom. So, I definitely can't see him defining the difference between taste and flavor. Actually that's a tough one, even for us scientists!

Let's start with taste. That's easy because taste is definitive and limited to five types: sweet, sour, bitter, salty, and umami, or savory, which are detected by receptors on the tongue. Flavor, by contrast, is more complex and more powerful. Rather than being sensed by taste buds, flavor is experienced in the brain, and the sense of smell is the key component.

A recent book, Neurogastronomy, by Gordon Shephard, explores how the brain's perception of flavor impacts eating habits, such as food preferences, and cravings. Flavor presents food in its full dimension which is why the smell of popcorn makes a person's mouth water while evoking good memories.

Scientists are beginning to understand the mechanism of flavor, which is mainly created by the sense of smell. While a person chews and swallows, they're also breathing, and when they exhale, pull in chemicals released by food into the nasal cavity, where they are sensed and transmitted to the brain. This is called retronasal smell. Once in the brain, a smell image is created. From there, flavor further engages the brain's higher, cognitive regions that control emotion and memory, creating more excitement or reward from food.

Shepard believes flavor's role in the brain has an impact on modern social, behavioral and medical issues - particularly on our inability to choose healthy foods. If flavor does play such a large role, it goes against evolutionary biologists's belief that our sense of smell has waned.