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Technical University of Munich

How big is a portion? Scientific journal “Appetite” publishes research findings on food consumption

Lehrstuhl-News |

Consumers often struggle in identifying how big a suitable portion size of a food is. The packaging is supposed to help them define the appropriate amount, and to relate this measure to their personal goals (e.g., maintaining body weight). However, the studies published by Prof. Dr. Königstorfer and co-authors show that the information presented on the packages is not always beneficial: Simply labeling a food “Fitness Food” can cause overconsumption of up to 50%.
[Translate to en:] Wie groß ist eine Portionsgröße? Bei einem Apfel scheint sich die Frage einfach zu beantworten, bei verpackten Lebensmitteln jedoch nicht


Fitness claims on packages

The labeling of food products often contains words such as “fit“, “active,“ or „sport.“ Also, athletes are often presented on food packages. If consumers are asked explicitly whether the labeling influences them, they typically claim that their behavior is not guided by such claims. However, a recently published study shows that consumer perception is indeed influenced. The study was designed to find out:

  •  Whether fitness claims on food packages cause overconsumption
  • What mechanism accounts for this effect

The studies

Two studies manipulated the labeling of a trail mix. In one experimental group, the participants had the chance to taste Fitness Trail Mix. In the second experimental group, the identical food was provided to them, except that it was called Trail Mix instead of Fitness Trail Mix. The participants remained unknown about the purpose of the study but fully debriefed at the end.

The deceptive effect of fitness cues

After having measured the actual quantity of trail mix poured into a container and the actual amount of food consumed, the authors compared the two experimental groups. The results are revealing. Although the participants did not differ in perceived appetite, individuals who had eaten the Fitness Trail Mix poured an average of up to 50% more into the container than persons from the control group. Consumption also increased and was well above the objectively normed portion size (which is equal to 30 grams for trail mix). After consumption, participants who ate the Fitness Trail Mix felt less guilty and stated that they were closer to the desired fitness – despite (or even due to) overconsumption!

What can consumers do about this?

Consumers should be aware of the fact that claims (e.g., fitness, low-fat, rich in vitamins) do not automatically go along with low-calorie content. If consumers do not watch their body weight, additional consumption should not cause a goal conflict. However, if individuals want to consume less calories and maintain (or reduce) weight, claims on products can have negative effects and make consumers feel “safe“ even though overconsumption may occur. The likelihood of a positive energy balance increases.

The study

Contact:

Prof. Dr. Jörg Königstorfer

Uptown Munich Campus D
Georg-Brauchle-Ring 60/62
80992 Munich
Phone: +49.89.289.24559
Fax: +49.89.289.24642
info.mgt(at)sg.tum.de

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