Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans

Area of Science:

• Behavioral Science
• Human Nutrition
• Cognitive Psychology

Background:

• Eating rate influences satiation and body mass index.
• Factors affecting eating rate include food texture, motivation, portion size, and palatability.
• The role of cognitive processes in adjusting eating rate remains underexplored.

Purpose of the Study:

• To investigate if cognitive estimation of remaining food volume influences eating rate.
• To determine if visual feedback of food volume impacts intake speed.
• To dissociate the effects of perceived portion size from actual consumed volume on eating rate.

Main Methods:

• A between-subjects design with 2 (amount seen: 300ml or 500ml) x 2 (amount eaten: 300ml or 500ml) conditions.
• Covert manipulation of food volume using a peristaltic pump to create congruent and incongruent visual-consumption scenarios.
• Assessment of eating rate (ml/sec) and post-meal fullness over 60 minutes using soup and dessert.

Main Results:

• In congruent conditions, eating rate was not affected by the actual volume consumed.
• In incongruent conditions, participants ate faster when they saw less but consumed more (300ml seen, 500ml eaten).
• Conversely, participants ate slower when they saw more but consumed less (500ml seen, 300ml eaten).

Conclusions:

• Eating rate is modulated by cognitive adjustments based on visual feedback of food volume.
• The perception of how quickly food disappears influences eating speed, independent of actual intake.
• Eating rate control involves visual perception, suggesting it's not solely a reflexive response to sensory input.