New research from Oxford University sheds light on the addictive nature of high-fat foods, such as fleshy fat yogurt or ice cream. According to brain researcher Fabian Grabenhorst and his colleagues, the brain area responsible for sensations and food attraction, the orbitofrontal cortex, becomes excited when recognizing fatty foods. However, the researchers were more interested in the melting oiliness of the food, which reduces friction as it slides against the tongue and mouth walls.
To test their hypothesis, they prepared vanilla-flavored milkshakes with varying fat and sugar content. In one option, they replaced fat with a thickener used in the food industry to give juiciness. Additionally, they procured pig tongues from a local butcher to measure the sliding friction of their milkshakes under conditions similar to those in the human mouth. The results showed that friction decreased according to the fat content of the shake.
Next, more than twenty test subjects tasted different milkshakes and were asked how much they were willing to pay for more. The researchers found that willingness to pay reflected both taste and mouthfeel associated with sliding friction. This part of the experiment was done so that subjects did not know that they were being observed by researchers. Fatty meals were piled on their plates especially by those whose orbitofrontal cortex reacted strongly to greasy mouthfeel in the shake experiment.
Grabenhorst told Nature magazine that their findings could help develop low-calorie foods that still have a satisfying texture and taste. The study was published in The Journal of Neuroscience