As the holidays approach, so do tasty treats laden with calories, many of them provided by fat. It's no wonder these delectables taste so good, according to a study published recently in the journal Physiology and Behavior. Despite a previous belief to the contrary, fat does have flavor after all.

Prevailing theory allows for five food tastes: the venerable sweet, salty, sour, bitter and the more recently discovered umami, which is evoked by monosodium glutamate (MSG). Fat, according to this view, only provides texture to food. But animal studies have suggested that there are chemical signals at work for detecting fat via taste or smell.

So Richard Mattes and graduate students in his laboratory at Purdue University recruited 19 adults willing to eat cream cheese in the name of science. After fasting overnight and having their blood fat levels tested, the subjects ate up. Some people both tasted and smelled the fatty cheese, others just tasted it and some only smelled it while the control group received no sensory stimulation at all. The scientists found that the blood fat levels of subjects who both tasted and smelled the food rose three times more than those of the control group. The fat levels of the subjects who tasted while wearing nose plugs rose a similar amount. People only allowed to smell the cream cheese, however, did not experience a rise in fat levels. "This tells us that taste is the stimulus that causes the rise in blood fat levels," Mattes explains.

If this is indeed the case, it may explain why fat-free foods just don't taste quite as good as their full-fat counterparts. "I wonder if the less-than-perfect performance of current fat replacers may be due to a lack of understanding of all mechanisms for fat perception," Mattes muses. "Failure to account for a taste component may compromise quality." Just another reason to reach for the real ice cream this holiday season.