Avoid the Clean Plate Club

Psychology behind eating ALL the food

Springtime tends to trigger a subliminal cleaning button that typically has us tossing dusty shoes from our hallway closets and unused duffle bags from under our beds.  New research suggests however, that the one thing we may not want to clean – is our plate!

A study published in Appetite looked into what compels us as adults to eat all of the food on our plate.  It’s an act that can be interpreted as a sign of appreciation, love, or plain old politeness.   Through a series of tests, investigators observed that cleaning one’s plate is actually more about the satisfaction we get when finishing or completing a meal, technically defined as consumption closure. 

One test offered 190 participants a bag of 3, 4, 5 or 8 Oreos, they were instructed to eat 3 cookies and were then asked a series of questions to gauge their desire to eat one more cookie.  The inclination to eat more was highest when there were just 1 or 2 cookies remaining as compared to 5.  This suggests that the amount left on plate (a lot vs. a little) makes a difference in whether we want to eat more of it. 

Another test created a scenario with 96 adults, in which they were asked to eat three slices from a personal pizza that had a total of 4 slices, followed by a series of questions to understand meal satisfaction and desire to eat more.  Participants were divided into two groups, one allowed to take leftovers home while the other was not.  They found that the group that was not allowed a doggie bag was more apt to feel as though they had “unfinished” business and a desire to continue eating after eating 3 slices.  Interestingly, surveys revealed that this group also perceived the last slice of pizza as being “less unhealthy” as compared to the group that was allowed to take the 4^th piece of pie home. 

Each of their tests reinforced that completing the meal and having closure is a major driver behind cleaning our plate, so much so that participants rationalized unhealthy foods as being less unhealthy, compelling them to eat the last bite. 

If you tend to be a part of the clean plate club, avoid diet sabotage.  Try using a smaller plate and put less on it—you can always go back for more and don’t be afraid to pack up your leftovers for lunch the following day.  The next time that the “just one bite”, “one more cookie”, “one sushi roll” thought creeps into your mind, remember this article and don’t let consumption closure get the best of you!

Published April 1, 2019