Two professors of marketing, Pierre Chandon, at INSEAD and Nailya Ordabayeva, at Boston College recently defined the “accuracy of less” in a research paper published in the Journal of Experimental Psychology: General. They showed that people are much better at judging decreasing portions than increasing ones. Professor Chandon said, “Our brains are very bad at judging quantity increases, but surprisingly accurate at judging quantity decreases.”
Research has shown that people consistently eat more food or drink larger amounts of beverages when they are offered larger portions, larger packages or bigger tableware. The 16-ounce bottle of Coke which seems so normal today was originally advertised as the “big size, serving 3.” For the first 50 years, the standard Coca Cola bottle was 6.5 ounces. Today a single serving of Coke at a quick service restaurant could be served in a 32-ounce cup with free refills available.
Through a number of experiments Professors Chandon and Ordabayeva showed people underestimate the true increase in size. Because our ability to judge an increase in size grows more slowly than the actual size, we underestimate actual size. For example, when a quick service restaurant meal was doubled in size, those estimating the size believed it only increased by 50%. This gross underestimate could easily result in over eating. The same holds true when test subjects were asked to tell how many pieces of candy were in a dish. Test subjects where shown 5 cups holding 37, 74, 148, 296, and 592 pieces of candy. They were told that the fist cup had 37 candies and were asked to estimate the number of pieces in the remaining cups. The average estimates were 57, 102, 184, and 296. In each case there was a gross underestimate of the actual count and for the largest amount people underestimated by 50%.
The theory of the accuracy of less shows that weight, volume or count of an object can never be lower than zero. When people are making judgements on decreases they have a natural lower end point of zero to judge against. When you are judging increases there is no upper boundary since theoretically increases could go on to infinity. When people estimate sizes that are smaller, they know that the size they are estimating is smaller than the reference but larger than zero. They have more information available to make an accurate estimate. That same range is not available to gauge increases because the upper limit is endless and hard to estimate.
What does this all mean to you? In order to judge food accurately you need benchmarks to judge against, plus you need to understand that without that benchmark increases in food sizes are hard to estimate correctly.
Here are some good visual clues that will help you accurately judge food portions.
· Computer mouse = a 4-ounce portion of meat, chicken or seafood and 1 medium backed potato.
· Yo-yo = a mini bagel or approximately 100 calories. How many yo-yos can you fit into your bagel, muffin or pastry? I bet it is more than one.
· Tennis ball = a medium piece of fresh fruit. Most fruit sold today is larger. Even good-for-you choices have been supersized.
· Ping-pong ball = a 2-ounce serving of cheese or 2 tablespoons of salad dressing, gravy, sour cream or peanut butter.
· Music CD = 1 medium-sized pancake or 1 small waffle.
· Quarter = 1 pat of butter or margarine.
© NRH Nutrition Consultants, Inc.
Jo-Ann Heslin, MA, RD, CDN is a registered dietitian and the author of 30 books. Available as eBooks from iTunes and Kindle/Amazon:
Healthy Wholefoods Counter
Complete Food Counter
Fat and Cholesterol Counter
Available in print from Gallery Books:
Most Complete Food Counter, 3rd Ed.
Your Complete Food Counter App: http://itunes.apple.com/us/app/your-complete-food-counter/id444558777?mt=8
For more information on Jo-Ann and her books, go to: www.TheNutritionExperts.com.