Somewhat related-

"Why Fat Tastes So Good"

No matter how cleverly prepared, fat-free foods never seem satisfying.
Now we know why. Nutritionist Philippe Besnard of the University of
Burgundy in France has found that the 10,000 taste buds on the tongue
seem to include a type that specifically responds to the flavor of fat.
If confirmed, it would be only the sixth known type, joining those that
sense sweet, salty, sour, bitter, and savory (also known as umami).
Besnard uncovered the fat sensor in the tongues of genetically
engineered mice that lacked the ability to make a protein called CD36.
Mice normally have a yen for fatty foods, but the altered animals
showed no preference for the stuff. Furthermore, regular mice release
fat-digesting secretions in their bowel and ramp up intestinal fat
absorption as soon as they taste fat; the modified mice displayed no
such response. Apparently, CD36 is the key protein that allows certain
mouse taste buds to respond to fat. Humans, whose sense of taste works
almost exactly like that of mice, almost certainly have the same taste
bud.
From an evolutionary perspetive, having a fat bud is a big advantage.
It causes animals to crav and consume high-calorie fatty foods and then
prompts their bodies to quickly and efficiently digest the fats,
storing away an energy reserve for times of starvation. If scinetists
can find a way to develop non-fattening foods that latch onto the fat
receptors, they may be able at long last to develop fat-free snacks
that can actually trick the tongue.

Discover magazine/ Feb. 2006 issue