We often assume that our appetite depends on how much food we’ve eaten, but a new study conducted in a completely dark restaurant has demonstrated that we don’t feel any more full if secretly slipped extra large portions of food. What we see, it seems, plays a big role in how hungry we feel.
The research, led by psychologist Benjamin Scheibehenne and published in the journal Appetite, invited participants to have lunch in a restaurant in downtown Berlin.
While the entrance bar was lit, the restaurant itself was pitch black and the volunteer ‘customers’ were served by blind waiters and waitresses who were capable of working in the dark.
The ‘customers’ ate two main courses in the dark dining area, but what they didn’t know, was that half were served normal-sized portions while the other half were served super-size portions that were more than a third bigger.
Afterwards, the light was switched on and they were offered a dessert that they could serve themselves.
The researchers measured how much dessert each person ate and the diners were asked to fill in a questionnaire where they estimated how hungry they were, how much they ate and whether they liked the food.
Exactly the same experiment was run a few weeks later, with different volunteers, but with everyone eating in the light, as in a normal restaurant.
For those who could see what they were eating, the size of their main course had a big effect on how full the diners felt and how much dessert they ate afterwards. But for those who dined in the dark, portion size didn’t seem to make a difference.
In other words, people were experiencing fullness based as much on their visual estimation of how much food they were eating as their actual physical consumption. Eating without seeing means we unwittingly eat more and feel less hungry.
This chimes was a 2005 study, where a research team created soup bowls that secretly refilled for some of the diners to the point where they ate three quarters more soup than others.
Despite this, those diners with the ‘bottomless soup bowls’ did not believe they had eaten more, nor did they feel themselves as more full than those eating from regular bowls.
The researchers from the Berlin study note that these findings show the importance of context for healthy eating and make an interesting point about how something as common as eating in front of the TV may affect how much we eat, simply by affecting how much we focus on our food.
Link to PubMed entry for study.