There is some confusion around the term ‘portion size’, since it is used differently by food manufacturers, regulatory agencies, and consumers. Serving sizes used for federal dietary recommendations are the amounts for optimal nutrition, while the food industry defines the amount as ‘customarily consumed per eating occasion’ – and further confusion arises from the industry’s use of phrases such as ‘super-size’ and ‘healthy portion’.
But this latest research suggests that how portions are described on product packages or menus can not only affect how they are perceived, but can also affect how much people eat and even consumers’ perception of how much they have eaten.
“Both the discrepancy between the standard portions and the typically consumed portions and the inconsistency in portion sizes across food providers contribute to people’s uncertainty about the appropriate amount to eat,” the study’s authors wrote. “…We show that size labels chosen by food and drink vendors (such as ‘small-medium-large’) can have a major impact on consumers’ purchase and consumption behavior. As such, food providers’ choice of size labels has many potential legislative and liability-related implications.”
The researchers conducted five studies, the results of which suggest that size labels affect how much people consume and how much food they think they have consumed. They found that when a large food item was labeled ‘small’, consumers generally felt less guilt – a phenomenon the authors refer to as ‘guiltless gluttony’.
“An implication of our results is that consumers can continue to eat large sizes that are labeled as smaller and feel that they have not consumed too much,” they wrote. “This can result in unintended and uninformed over-consumption, which is clearly ridden with significant health ramifications, and size labels could be contributing to the rampant obesity problems in the United States.”
The researchers suggest that their findings could have implications in terms of food labeling policy and claim that there is a need for stricter labeling laws and more vigilant monitoring of the food industry’s portion size labels.
Source: Journal of Consumer Research
Published online ahead of print
“Guiltless Gluttony: The Asymmetric Effect of Size Labels on Size Perceptions and Consumption”
Authors: Nilüfer Z. Aydinoğlu and Aradhna Krishna