Portion Distortion

There's no doubt that the portion sizes of restaurant meals and packaged foods has increased in the last twenty years. There's a lot of discussion about "supersizing" and the effect that it has had on the rise in obesity in our culture. Many feel that the larger portions that we are served has an effect on what we will serve ourselves. Even twenty years ago there were signs of this and a study conducted in 1984 indicated a change in perception of portion size amongst young adults.

In an effort to evaluate the differences in the last two decades, Jaime Schwartz and Carol Byrd-Bredbenner repeated the earlier study looking at how college students chose foods at meals from a buffet (J Am Diet Assoc 2006;106:1412-1418). 177 students participated and served themselves breakfast, lunch or dinner and their meals were weighed. The portions were scored against the recommended portion sizes.

Students were able to choose freely from a breakfast menu of cornflakes, milk on cereal, sugar for cereal, toast, butter, jelly, milk for drinking and orange juice. Lunch buffets were stocked with tuna salad, either white or whole wheat bread, tossed salad, salad dressing, fruit salad and soda. Dinner consisted of the same choices as lunch. (The dinner meal was added to the newer study to see if there was a change in participant's portion sizes depending on the time of day.)

The portion sizes of cornflakes, the milk on cereal and jelly were found to be more than 125% of the standard portion. This was also true of lunch choices including butter, tuna salad, tossed salad and salad dressings. When the scoring system used by the researchers was applied to the overall meals there was an increase in the total portion size measures as well. Larger portions were taken by the students in this study than those in the 1984 research.

What this means for you:

Portion size is probably the most important key to eating healthy. Look carefully at packages for what the correct measure is for each food and follow it carefully. Here's a "Dr. Tim Says..." article to help you understand normal portion sizes.

First posted: November 10, 2006