Bottomless bowls: why visual cues of portion size may influence intake.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 15761167 · doi:10.1038/oby.2005.12
What was done
Fifty-four participants (aged 18 to 46 years, BMI 17.3 to 36.0 kg/m2) participated in a between-subject experiment with two visual cue conditions: eating soup from an accurate normal bowl versus an imperceptibly self-refilling bowl built into a modified table. Measured outcomes were actual intake volume, estimated intake, consumption monitoring, and self-reported satiety.
What was found
Participants assigned to self-refilling bowls consumed significantly more soup than those with normal bowls (14.7 +/- 8.4 oz vs. 8.5 +/- 6.1 oz; F(1,52) = 8.99, p < 0.01), an increase of 73%. Despite the higher intake, they did not believe they had consumed more food and did not report feeling more sated, an effect that was unaffected by BMI.
Why it matters
This experiment demonstrates that visual portion cues can override internal physiological signals of satiety, showing that people rely heavily on visual cues rather than physiological fullness to determine meal termination.
Limits
The study was conducted in a small sample (n = 54) during a single lab-based meal with only one food type (soup). The abstract does not report post-meal caloric compensation, long-term intake effects, or detailed demographic breakdown beyond age and BMI range.
Cited by
- supports In Brian Wansink's soup bowl experiment, participants eating from secretly self-refilling bowls consumed significantly more food than those eating from regular bowls.