According to research conducted by a team of brain scientists at Oxford University, people tend to prefer high-fat foods such as fleshy fat yogurt or ice cream over lighter alternatives. The study found that the high-fat product is not only more delicious but also addictive due to its mouthfeel.
The researchers used vanilla-flavored milkshakes with varying fat and sugar content in their study. They added a thickener used by the food industry to give juiciness to one option instead of fat. They also procured pig tongues from a local butcher and measured the sliding friction of their milkshakes with different compositions in conditions reminiscent of the human mouth.
The results showed that the friction really decreased according to the fat content of the shake. More than twenty test subjects slurped milkshakes and were asked how much they were willing to pay for more milkshakes after tasting them. Willingness to pay told the researchers how much the participants liked each vanilla drink. During the tasting, their brains were imaged with a functional magnetic resonance imaging device, which revealed that the differences in composition and pleasantness of the shakes were reflected in reactions of orbitofrontal cortex.
The preference for high-fat foods was partly explained by mouthfeel associated with sliding friction, which affects people’s food choices. The study confirmed this when test subjects could taste three curries with different fat content and choose their favorite for lunch while being observed without knowing it. Fatty meals were piled on their plates, especially by those whose orbitofrontal cortex had reacted particularly strongly to greasy mouthfeel in the shake experiment.
Fabian Grabenhorst, who led the study, believes that these findings can help develop low-calorie foods that are still satisfying and enjoyable for consumers to eat. The study was published in The Journal of Neuroscience.