Portion Control

Here is the latest email from Dr. Jacobs.

Portion Control – How Much Are You Really Eating?

Over the years, portion sizes of all different types of foods and beverages have increased…and so have our waistlines. Meals are super-sized, soft drinks are mega-sized, and restaurants serve enough for two, or maybe even three people. We have become so used to the large portion sizes that they have become the new “norm.” If we were offered anything smaller, we would automatically think it was not enough, or we are not getting enough for our money. Did you know that the difference in the number of calories in a bagel you could buy today from one 20 years ago? How about between cheeseburgers? Try the National Heart, Lung, and Blood Institute’s Portion Distortion Quiz to see how well you know how portion sizes and the amount of calories in foods have changed over the past 20 years.

Even if you are aware of how big the portion sizes are today, you may be thinking, “I’m not fooled by the large portion sizes and they don’t influence how much I actually eat.” The question is: Are you really sure?

Brian Wansink, a professor and director of the Cornell University Food and Brand Lab, has studied food psychology, eating behavior, and why we eat what we eat for years. His best-selling book, Mindless Eating: Why We Eat More Than We Think, entertainingly discusses his creative research projects conducted in food psychology laboratories and real-world settings. Wansink’s research has prompted people to think about what is really causing them to consume the amount of food they do. Below are a few of the studies and findings that focus on how portion sizes influence how much you eat:

Does the Size of the Popcorn Bucket Matter?
Several years ago, individuals who arrived at a Chicago suburban movie theater to see a matinee movie were given free soft drinks and either a medium- or large-sized bucket of stale popcorn. Who ate the most? Individuals who were given the large bucket ate 53% more popcorn than those given a medium-sized bucket. This averages to approximately 173 more calories (of stale popcorn)!

Does the Size of the Bag of M&M’s Matter?
Forty adults attended a PTA meeting and were asked to provide feedback on a video. To thank everyone in advance, each person was given either a half-pound or one-pound bag of M&M’s to enjoy during the video. Who ate the most? Individuals who were given the one-pound bag ate an average of 137 M&M’s, whereas those given the half-pound bag ate an average of 71 M&M’s. This 66-M&M difference equates to over 250 calories!

Does the Size of the Container Matter Even When Previously Lectured on the Topic?
Graduate students attended a 90-minute lecture on how people generally take more from larger containers. Six weeks after the lecture, they were invited to a Super Bowl party, where they were placed in either a room with two gallon-sized or four half-gallon-sized bowls of Chex Mix. Who took the most? Students who were in the room with the gallon-sized bowls of Chex Mix took and ate more than 50% more than those in the room with half-gallon bowls. Even though they had previously been lectured on the size biases, those offered snacks in larger containers still took more than those offered snacks in smaller containers.

Initially, you may think you are not influenced by these large portion sizes, but the research does challenge you to think again. Furthermore, if you have noticed that you’ve started to gain some weight, you may want to take a closer look at your portion sizes. And, just because the portions appear to be the new “norm,” it does not mean you need to be eating that amount. If you are like most of us, you may need a reminder of what the recommended or standard size of servings look like. Here are some guidelines for one serving:

1 slice of bread = the size of a cassette tape

1 cup of cereal = the size of your fist

½-cup of pasta, rice, or ice cream = the size of ½ of a baseball

1 medium piece of fruit = the size of a baseball

1 baked potato = the size of your fist

1 tsp. of margarine = the size of one dice

3 oz of meat = the size of a deck of cards

2 tbsp. of peanut butter = the size of a ping-pong ball

References:
National Heart, Lung, Blood Institute’s Portion Distortion Quiz:
( http://hp2010.nhlbihin.net/portion/ )
Wansink, B. (1996). Can package size accelerate usage volume? Journal of Marketing, 60(3), 1-14.
Wansink, B. (2007). Mindless eating: Why we eat more than we think. New York: Bantam-Dell.
Wansink, B. & Cheny, M. (2005). Super bowls: Serving bowl size and food consumption. Journal of the American Medical Association, 293(14), 1727-28.
Wansink, B., & Park, S. (2001). At the movies: How external cues and perceived taste impact consumption volume. Food Quality and Preference, 12(1), 69-74.