In the world of indulgent treats, the battle between fleshy fat yogurt and lighter alternatives is fierce. But what if it’s not just about taste that has people choosing high-fat products over their healthier counterparts? Researchers at Oxford University have uncovered a new reason for this preference: the mouthfeel of these foods.
According to a study published in The Journal of Neuroscience, the brain area responsible for sensations and food attractiveness, the orbitofrontal cortex, reacts more strongly to fatty foods than to leaner alternatives. This is because fat increases the viscosity of liquid food, which reduces friction as the food slides against the tongue and walls of the mouth.
To test this theory, researchers prepared vanilla-flavored milkshakes with varying fat and sugar content. They also procured pig tongues from a local butcher to measure sliding friction in conditions reminiscent of the human mouth. The results were clear: as fat content increased, friction decreased.
Next, 20 test subjects were asked to taste milkshakes with different compositions and rate their willingness to pay for more. Brain imaging technology was used during tasting to track responses in the orbitofrontal cortex. As expected, differences in shake composition and pleasantness were reflected in brain activity.
The study found that mouthfeel played a significant role in participants’ food choices. In another part of the experiment, subjects were asked to choose their favorite curry out of three options with different fat content for lunch without knowing they were being observed by researchers. Those whose orbitofrontal cortex reacted strongly to greasy mouthfeel in the shake experiment tended to pile more fatty meals onto their plates.
Dr. Fabian Grabenhorst, lead researcher on the study, explained that these findings could help develop low-calorie foods with improved mouthfeel properties. “By understanding how our brains process sensory input related to food texture and taste,” he said, “we can potentially design new foods that are both delicious and healthy.”