As a nutrition researcher tracking portion sizes and labels manufacturers use to describe such sizes, I have seen food portions not only grow larger over the years, but the labels to describe foods and drinks have also changed.
For example, when McDonald’s opened in the 1950s, the company offered one size soda, which was 7 ounces; today’s 12 ounces is labeled a kid’s size and the 16-ounce is labeled small. Similarly, when Burger King opened, the company offered a 12-ounce small and a 16-ounce large soda. The 12-ounce is no longer sold and the 16-ounce comes as part of the value meal. Burger King’s small soda is now 20 ounces, the medium is 30 ounces, and the large is 40 ounces.
Does anyone pay attention to these label descriptors? And do they influence how much we really eat? Apparently yes, according to a new study published in Health Economics by Cornell University researchers David Just and Brian Wansink.
The study found that labeling a food as “regular” or “double size” affects how much consumers will eat, regardless of how big or small the portion size actually is.
The researchers served subjects two different portions of pasta in either a one cup-portion or a two-cup portion. For some of the subjects, the two different size portions were labeled “half-size” and “regular.” For the other subjects, the identically-sized portions were labeled “regular” and “double-size.” The labels for the first group of subjects indicated that the two-cup pasta portion was the regular size, while it was suggested to the second group of subjects that the one-cup pasta portion was the regular size.
The study concluded that varying the “regular” portions affected how much the subjects actually ate. Subjects ate more food when the portion was labeled “regular” than when it was labeled “double-size” despite the fact that the two sizes were actually the same size.
The subjects were also willing to pay more for a larger sounding portion size.