Larger Food Packaging Size Increases Consumer Estimates of Portion Sizes

07 Oct 2015 --- The size of a food package can influence people’s perception of portion size. Larger food pack sizes can increase consumer estimates of portion sizes finds a new study completed by the European Food Information Council (EUFIC) and the University of Surrey.

The results of the study, published in the journal Appetite, found that crisps, chocolate, lasagne and cola type drinks all showed evidence of increased portion size estimates when participants were presented with larger pack sizes. This was also observed for multiple food items such as chicken nuggets, sweets and biscuits where participants were asked how many items make up a portion.

“Our results indicate a small but significant ‘pack size effect’ across all countries and for different types of food and drinks. If people were to actually consume the portions they estimate in this study, there would be a substantial increase in energy intake in each of these eating occasions,” said Dr Sophie Hieke, Head of Consumer Insights at EUFIC.

The study calls for more research to better understand how people estimate portions for example by studying whether people see portions and portions mentioned on food packs as a realistic amount of food or drink someone is likely to consume in one sitting as opposed to something someone should consume in one sitting.

“Answering this question would give us insight into the conceptualisation of food portions in people’s minds and the rationale behind the ratings people give in portion size experiments,” said Professor Monique Raats, Director of the University of Surrey's Food, Consumer Behaviour and Health Research Centre.

The study, which was carried out on a sample of 13,177 participants in six European countries: France, Germany, Poland, Spain, Sweden and the UK, found gender to be an important factor. Despite both men and women reporting larger portion sizes overall, men presented a larger portion size increase and were more affected by larger pack sizes. Differences were also observed between countries involved in the study even though portion sizes increased overall in every country when presented with larger pack sizes. The participants from Sweden, Poland and Germany indicated a larger portion size increase compared to those in Spain, France and the UK when presented with the same pack size.

Participants who regarded portion information on food and drink packages to be irrelevant displayed a tendency to estimate larger portion sizes compared with those who regarded the portion information on packaging as relevant. Age also played a role; increased age was associated with smaller portion size estimates.

The authors note that the study did not measure actual intake and that further research would be needed to test whether the increases in portion sizes do lead to the predicted increase in energy intakes over time and whether or not that effect is compensated and indeed results in an actual increased intake.