How does your body recognize the fat in certain foods? Until now, researchers assumed that fat was a texture that could be felt in its creaminess but not specifically tasted. But new research suggests that fat may be a taste in and of itself. This may also explain why certain people are more drawn to it and why some are more prone to obesity.

For decades, scientists recognized four specific tastes — salty, sweet, sour and bitter. Then in 2002, a fifth basic taste, umami or savoriness, was confirmed. Now growing evidence indicates that the list may need to be adjusted once again to add fatty as the sixth basic taste quality.

Let's start with a quick primer on food science. When researchers talk about taste, they're talking about something that can be perceived with the tongue alone. Close your eyes and plug your nose and you will recognize salt if it is sprinkled on your tongue. Next comes flavor, which is what we perceive when both taste and smell work together. Without your nose, you may taste something as sweet, but you won't recognize it as chocolate without the aroma.

Up until now, fat was not defined as a taste or a flavor, but rather as something that could be perceived by the third sensory system, touch. The trigeminal nerve runs along the face with nerves extending to the eyes, nose, tongue and teeth. This is the nerve that we use to sense pain, irritation, texture and temperature. It's how you know that those peppers are hot or that a peppermint treat tastes "cool." Food scientists always assumed that fat could be felt, not tasted.

But a new study has turned this idea on its head. Researchers at Purdue University have found that 64 percent of people can taste fat when both the eyes and the nose are out of the picture. Wearing nose clips and sitting in a room with disguising red lighting, participants were able to distinguish the taste of fat in food. And interestingly, it tasted gross.

This is partly explained by the fact that in order to isolate the fat, researchers used food samples that contained a higher concentration of fatty acids than what is normally found in foods. Test subjects described the samples with shorter fatty acid chains as sour tasting while those with longer fatty acid chains tasted pungent or irritating.

So why does considering fat as a "taste" even matter? Researchers aren't exactly show how it works, but they think that a person's perception of fat as a taste could influence the propensity for obesity. For instance, someone who can easily distinguish the fat taste may be more likely to crave fat as a result. Conversely, someone with fine-tuned fat receptors may be more easily satisfied by smaller amounts of fat in their foods than someone who needs more fat before it registers.

It's not clear how the taste of fat works in influencing our food choices, but it's pretty clear that many of us can taste the fat in our foods, even if we don't even know it.

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