The Nose Knows: Detecting Fat in Food

Our bodies are amazing organisms. Did you know that our noses might actually b able to smell differences in dietary fat levels in foods—as in, we can smell which milk is skim, 2% and whole?

New research out of the Monell Chemical Sences Center recently conducted a small study, in which participants smelled different samples of milk and tried to distinguish between them. PLoS ONE published the study in January, which found that the participants really could distinguish the milk based on smell.

Can you smell the difference between full fat ice cream and fat-free? Lunström's study says yes.
Image: Shutterstock

How is that even possible? The study’s lead author, psychologist Johan Lunström, says that he believes it comes down to evolution. We “need energy to survive,” he says. And, back when we didn’t have those helpful nutritional charts available, “detecting fat would have been very valuable to us.”

Fat, though it’s gotten a bad reputation over the years, is actually an essential part of the human diet. We need energy to survive, and foods that are naturally fatty (like nuts and fresh milk) are perfect for sating that appetite. One reason I actually prefer whole milk over skim is because the fat keeps me feeling full longer—so even though it has more calories, I don’t get hungry again as soon.

The study isolated the fat in milk by using powdered milk, and all the samples had the same concentration of powder. “The only thing that these powders differed in was the amount of fat,” Lundström says. “Otherwise, the samples are identical.”  

Previous studies had found that humans could smell fatty acids in their purest form. Next, Lundström says he hopes to find out how we can smell the fat, if we can recognize it in more complex foods, and in what ways this ability affects human behavior.