Why do we Crave Fatty Food? Latest Neuroscience Research Unveils Some Clues

The mouthfeel of melting ice cream is so tempting that many of us can't stay away from gulping dollops of it. Not only ice cream but several other rich, high-fat foods provide such temptations, and even after knowing about gaining extra weight, we often tend not to miss the tastes. But for neuroscientists, it is a matter to delve into the brain; ultimately, we are attracted to such foods guided by the brain. The question is how and which brain areas influence eating behaviour.

In a recent paper published in 'The Journal of Neuroscience', scientists claim to identify the brain area that responds to fatty foods and drives cravings. The findings are in addition to understanding what drives liking for some foods. The research suggests that the smooth texture of fatty foods like ice cream influences eating habits.

The Experiment

In the research paper, the scientists claimed to have coupled food engineering techniques with functional neuroimaging techniques. At first, they tried to quantify the mouthfeel of the fatty foods. For this, the researchers prepared milkshakes containing different fat and sugar contents and put each of these samples between two pig tongues.

In the experiment, the researchers slid the pig tongues with each other, having different milkshakes. By doing this, they quantified the amount of friction between the surfaces of the tongues and obtained a numerical value about the smoothness of each of the shakes.

The researchers, hereafter, provided the milkshakes to 22 participants. The shakes had the same sugar and fat contents used for measuring the smoothness of the pig tongues. After tasting the shakes, the participants were asked to rank them by saying how much they would spend to drink a full glass.

Simultaneously, the participants were undergoing brain scans to judge which brain areas were more responsive in choosing the shakes to understand which ones they liked the most. The brain scanning revealed that the brain region named the orbitofrontal cortex (OFC) reflected the texture of the shakes. Significantly, the OFC is also involved in reward processing (which depicts how the brain judges which work is beneficial). The brain scans also examined the activity patterns of the OFC, which reflected the preference of the participants in spending the milkshakes of their choice.

Hereafter, the participants were invited back to the laboratory for a free lunch. The researchers provided them with curries with a varied amount of fats in them. Without the participants' knowledge, the researchers measured how much of each curry the participants ate.

The researchers wanted to know whether the information obtained from brain scans can be extended to finding food intake. They found that the participants who liked the fatty curries more had their OFCs more sensitive to fatty texture. On the other hand, those who don't prefer more fatty curries have their OFCs less sensitive to the fatty texture.

"We found that a specific area of the brain's reward system—the orbitofrontal cortex—detects the smooth texture of fatty foods in the mouth and links these sensory inputs to economic valuations that guide eating behaviour," the researchers wrote about their findings in the article adding "These findings can inform the design of low-calorie fat-replacement foods that mimic the impact of dietary fat on oral surfaces and neural reward systems," highlighting the possible way of dietary planning playing with the neurological underpinnings of eating behaviour.

Ivan de Araujo, a neuroscientist at the Max Planck Institute for Biological Cybernetics, Tubingen, Germany, while commenting on the findings, was quoted to have said in an article by Max Kozlov at Nature, "These findings "add a new dimension" of the eating experience to scientists' understanding of what motivates people to choose certain foods."