Because many of us find it difficult to estimate correct portion sizes and many food providers throughout the world use slightly different portion sizes, we have found it easy to rely on size labels like 'small', 'medium', 'large', or 'extra large' when purchasing and consuming food. Unfortunately, recent research from the University of Michigan indicates that we as consumers easily misinterpret these size labels.
In a series of 5 studies, nutrition researchers tested consumer's ability to differentiate sizes based on how they were labeled and to determine if the size labeling had an impact on consumption habits. Some of the observations recorded by these researchers included:
- Labeling a large size as 'small' or 'medium' caused study subjects to perceive them as 'small' or 'medium' rather then recognizing the true size.
- Subjects consumed more food when they perceived large portion sizes to be small or medium based on the size label used.
- Subjects found it difficult to believe that an item labeled 'medium' or 'large' was in fact the size labeled if the item appeared visually small.
- Switching 'small' and 'large' labels caused some subjects to perceive a small item as larger than a large item.
- Individuals less likely to be deceived by the size labels placed on the food were those who were very nutrition conscious.
Overall, the researchers noted that consumers typically underestimate how much they eat and the underestimation becomes larger when the meal size increases. This can clearly lead to over consumption of food on a daily basis. Unfortunately, this happens without us realizing it. Since we generally believe the size label, we tend to believe that we have not consumed too much and feel less guilty about what we are eating.
This is interesting information in the wake of the recent fast food marketing report (www.fastfoodmarketing.org), which indicated that some fast food restaurants are simply re-naming their portion sizes to give a smaller appearance rather than actually serving smaller sizes. For those of us that noticed 'smaller' portion sizes at our favorite fast food restaurant, we might not actually be eating less like we thought because of our tendency to believe the size label. Becoming more nutritionally aware, particularly about portion sizes, is an important step in our ability to choose foods wisely and fight obesity.
Aaron Tabor, MD
Diet, Anti-Aging, and Nutritional Cosmetic Expert
Author of Dr. Tabor's Diet
and FIGHT NOW
Learn more about Dr. Tabor's diet and anti-aging research at www.DrTabor.com
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- Aydinoglu NZ, Krishna A. Guiltless gluttony: the asymmetric effect of size labels on size perceptions and consumption. Journal of Consumer Research 2010; doi: 10.1086/657557.