Researchers conducted an experiment to see if participants would stop eating from a bottomless soup bowl. The researchers hooked up tubes to the bottom of a soup bowl, and it kept filling even as the participant ate the soup. Would they stop eating when full, or just keep eating?
The participants who ate from a self-filling bowl ate 73% more than participants who ate from a regular bowl, but did not feel they had eaten more, and did not feel more full! The study result didn’t change based on the participant’s BMI.
Why is this important? It shows that we judge the amount of food we eat more with our eyes then on how full we fill. (https://www.ncbi.nlm.nih.gov/pubmed/15761167)