For most of us, portion control is the Achilles heel of an otherwise healthy diet.
Proper portion size varies by food, depending on its "calorie density”, but most of us probably aren't paying precise attention.
Luckily, visual cues that trick the brain can help us control portion size … without a calorie calculator, measuring cup, or any sense of deprivation.
Much of the notable research in this realm comes from Professor Brian Wansink's Food and Brand Lab at Cornell University.
Dr. Wansink and his colleagues have probed the effects of a psychological phenomenon known as the "Ebbinghaus-Titchener size-contrast illusion”.
These illusions make us misjudge the size of two identical circles, based on their surrounding context.
For example, the more white space surrounds a circle, the smaller we think it is … even though its size hasn't changed.
Conversely, that same serving of food will look more generous (and satisfying to the mind) when served on a small plate.
However, as we'll see, visual cues exert opposite effects when it comes to the size of plates and bowls versus the size of tables.
Downsize your plates and bowls
Starting in 2006, studies by Wansink's team proved that the size-contrast illusion applies to our plates.
In one experiment, professor Wansink's team gave two sets of campers different-sized bowls.
Not only did the campers given the larger bowls consume 16 percent more food, they mistakenly estimated that they'd eaten 7 percent less.
The easy fix? Swap your dinner plates for smaller salad plates.
Professor Wansink's research found that humans find a plate most aesthetically pleasing when 3/4 of it is covered by food.
As long as the amount of food versus the plate size meets or exceeds that ratio, you probably won't even notice you're eating less food.
In other words, the smaller the plate, the less food it will take to satisfy our brains … and the appetites it controls.
Upsize your dining table
New research from Cornell's Food and Brand Lab shows that table size also has a major impact on how much food we consume (Brennan D et al. 2016).
Surprisingly, the new findings establish a table-size rule that's the exact opposite of the "use smaller plates” rule.
To test the impact of table size on food consumption, the Cornell team divided four large round pizzas (all the same size) into standard-size slices (eight pieces per pie) or small slices (sixteen pieces per pie).
Then they placed each pizza on different tables:
- Two tables that were barely larger than the pizza itself: one holding a pie with small slices, one holding a pie with standard-size slices
- Two tables that were about the size of a normal dinner table: one holding a pie with small slices, one holding a pie with standard-size slices
They divided 19 college students between the four tables, and told them to eat as much pizza as they would like.
And the results seem quite counterintuitive, given prior findings about the effect of plate size.
When students were served small slices of pizza on small tables, they perceived them as smaller portions, they ate more slices.
Conversely, when students were served small slices on the larger tables, they took the same number of slices as the students who were served standard-size slices on small tables.
Because those slices were half the size of the standard slices, taking the same number of slices meant they were eating only half as much pizza.
What's the combined takeaway of the two studies?
Serve meals on small plates – mostly covered with food – at large tables.
If you don't have control over plate or table size, remember these rules of thumb:
- A 3 oz. serving of meat is about the size your palm or a deck of playing cards.
- A 3 oz. serving of fish is about the size of a checkbook
- One serving of cheese is the size of six dice
- One half cup of cooked rice or pasta should be about the size of a tennis ball
- One serving of raw fruits or veggies should be about the same size as a baseball
- A quarter cup serving of dried fruits and nuts is about the size of a golf ball
- Brennan D, Payne CR, Bui M. (2016). Making Small Food Units Seem "Regular”: How Larger Table Size Reduces Calories to be Consumed. The Journal of the Association for Consumer Research, 1.
- Brennan D, Payne CR, Bui M. Making Small Food Units Seem Regular: How Larger Table Size Reduces Calories to Be Consumed. Journal of the Association for Consumer Research 1, no. 1 (January 2016): 115-124.
- Schwartz J, Byrd-Bredbenner C. Portion distortion: typical portion sizes selected by young adults. J Am Diet Assoc. 2006 Sep;106(9):1412-8.
- van Ittersum K, Wansink B. Extraverted children are more biased by bowl sizes than introverts. PLoS One. 2013 Oct 30;8(10):e78224. doi: 10.1371/journal.pone.0078224. eCollection 2013.
- van Kleef E, Shimizu M, Wansink B. Serving bowl selection biases the amount of food served. J Nutr Educ Behav. 2012 Jan-Feb;44(1):66-70. doi: 10.1016/j.jneb.2011.03.001. Epub 2011 Oct 6.
- Wansink B, Painter JE, North J. Bottomless bowls: why visual cues of portion size may influence intake. Obes Res. 2005 Jan;13(1):93-100.
- Wansink B, Payne CR, Chandon P, Rozin P. Internal and External Cues: French and American explanations for mindless eating. FASEB J. 2006 20:A175-A176.
- Wansink B, Payne CR, Chandon P.Internal and external cues of meal cessation: the French paradox redux? Obesity (Silver Spring). 2007 Dec;15(12):2920-4.
- Wansink B, Payne CR. Counting bones: environmental cues that decrease food intake. Percept Mot Skills. 2007 Feb;104(1):273-6. Wansink B, van Ittersum K, Painter JE. Ice cream illusions bowls, spoons, and self-served portion sizes. Am J Prev Med. 2006 Sep;31(3):240-3.
- Wansink B, van Ittersum K, Payne CR. Larger bowl size increases the amount of cereal children request, consume, and waste. J Pediatr. 2014 Feb;164(2):323-6. doi: 10.1016/j.jpeds.2013.09.036. Epub 2013 Nov 16.
- Wansink B, van Ittersum K. The Visual Illusions of Food: Why Plates, Bowls and Spoons Can Bias Consumption Volume. The FASEB Journal. 2006;20:A618