title: The pack size effect: Influence on consumer perceptions of portion sizes.
abstract: Larger portions as well as larger packs can lead to larger prospective consumption estimates, larger servings and increased consumption, described as 'portion-size effects' and 'pack size effects'. Although related, the effects of pack sizes on portion estimates have received less attention. While it is not possible to generalize consumer behaviour across cultures, external cues taken from pack size may affect us all. We thus examined whether pack sizes influence portion size estimates across cultures, leading to a general 'pack size effect'. We compared portion size estimates based on digital presentations of different product pack sizes of solid and liquid products. The study with 13,177 participants across six European countries consisted of three parts. Parts 1 and 2 asked participants to indicate the number of portions present in a combined photographic and text-based description of different pack sizes. The estimated portion size was calculated as the quotient of the content weight or volume of the food presented and the number of stated portions. In Part 3, participants stated the number of food items that make up a portion when presented with packs of food containing either a small or a large number of items. The estimated portion size was calculated as the item weight times the item number. For all three parts and across all countries, we found that participants' portion estimates were based on larger portions for larger packs compared to smaller packs (Part 1 and 2) as well as more items to make up a portion (Part 3); hence, portions were stated to be larger in all cases. Considering that the larger estimated portions are likely to be consumed, there are implications for energy intake and weight status.
authors.affiliation: European Food Information Council, Rue Paul Emile Janson 6, B-1000 Brussels, Belgium. Electronic address: Sophie.Hieke@eufic.org.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hieke
authors.affiliation: European Food Information Council, Rue Paul Emile Janson 6, B-1000 Brussels, Belgium. Electronic address: katpalascha@hotmail.com.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Palascha
authors.affiliation: Division of Psychology, School of Social and Health Sciences, Abertay University, Bell Street, Dundee DD1 1HG, UK. Electronic address: c.jola@abertay.ac.uk.
authors.forename: Corinne
authors.initials: C
authors.lastname: Jola
authors.affiliation: European Food Information Council, Rue Paul Emile Janson 6, B-1000 Brussels, Belgium. Electronic address: jo.wills@eufic.org.
authors.forename: Josephine
authors.initials: J
authors.lastname: Wills
authors.affiliation: Food, Consumer Behaviour and Health Research Centre, School of Psychology, Faculty of Arts and Human Sciences, University of Surrey, Guildford GU2 7XH, UK. Electronic address: m.raats@surrey.ac.uk.
authors.forename: Monique M
authors.initials: MM
authors.lastname: Raats
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002755:Choice Behavior; D003469:Culture; D004522:Educational Status; D002149:Energy Intake; D005060:Europe; D005260:Female; D018857:Food Packaging; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D062407:Meals; D008875:Middle Aged; D064787:Portion Size; D012737:Sex Factors; D055815:Young Adult
keywords: Cultural differences; Food labelling; Pack size; Portion estimation; Portion size