A Neural Mechanism in the Human Orbitofrontal Cortex for Preferring High-Fat Foods Based on Oral Texture

Area of Science:

• Neuroscience
• Sensory Science
• Food Science

Background:

• Overconsumption of high-fat foods drives weight gain.
• Neural mechanisms linking oral fat sensation to reward and eating behavior are unclear.

Purpose of the Study:

• Investigate how the human orbitofrontal cortex (OFC) translates oral fat sensations into reward valuations.
• Determine the specific oral-sensory parameters that influence the reward value of dietary fat.

Main Methods:

• Utilized novel food-engineering to create nutrient-controlled liquid foods varying in fat and sugar.
• Employed functional neuroimaging (fMRI) while participants sampled foods and placed bids.
• Quantified the coefficient of sliding friction as a key oral-sensory parameter.

Main Results:

• OFC activity encoded the coefficient of sliding friction, reflecting the mouthfeel of fatty liquids.
• Distinct OFC activity patterns reflected economic valuations integrating sliding friction with other food properties.
• Neural sensitivity of the OFC to oral texture predicted individual fat preferences and consumption.

Conclusions:

• The brain's reward system senses dietary fat through oral sliding friction, a mechanical parameter influencing food interactions and eating experiences.
• The OFC plays a specific role in evaluating oral food textures to mediate preference for high-fat foods.
• Findings can inform the design of healthier fat-replacement foods.