The Sydney Morning Herald claims that Australian scientists have detected a sixth taste: FAT.
Those people who are highly sensitive to the taste of fat tend to eat less of it, and have significantly lower body mass.
Fat flavour can now be added to the other known tastes: sweet, salt, sour, bitter, and umami - a taste for protein-rich foods.

Researchers have found that humans can identify the taste of fat by its chemical composition, rather than by its texture. ''Fat has a very nice mouth feel to it but it appears that fat is activating something in the oral cavity independent of texture.''
Just like the other tastes, different individuals may be very sensitive to sweet tastes, while somebody else may be insensitive, this is common throughout the tastes, and it's exactly what we're finding with fat. ''It appears hypersensitive people have a mechanism that is telling them to stop eating it, he said.

According to the scientists, all humans can taste fat in varying degrees, but some are more sensitive to it than others, just as with sweetness and saltiness. The scientists are trying to account for these sensitivities in fat flavor detection, which could lead to new ways to treat obesity. Or maybe it's because people consider these things edible-because you know an egg and cheese on a cinna-bun is the perfect way to start the day!