Portion size me: Plate-size induced consumption norms and education futility

B. Wansink, Koert van Ittersum

Research output: Contribution to journalArticleAcademicpeer-review

154 Citations (Scopus)

Abstract

Research on the self-serving of food has empirically ignored the role that visual consumption norms play in determining how much food we serve on different sized dinnerware. We contend that dinnerware provides a visual anchor of an appropriate fill-level, which in turn, serves as a consumption norm (Study 1). The trouble with these dinnerware-suggested consumption norms is that they vary directly with dinnerware size-Study 2 shows Chinese buffet diners with large plates served 52% more, ate 45% more, and wasted 135% more food than those with smaller plates. Moreover, education does not appear effective in reducing such biases. Even a 60-min, interactive, multimedia warning on the dangers of using large plates had seemingly no impact on 209 health conference attendees, who subsequently served nearly twice as much food when given a large buffet plate 2 hr later (Study 3). These findings suggest that people may have a visual plate-fill level-perhaps 70% full-that they anchor on when determining the appropriate consumption norm and serving themselves. Study 4 suggests that the Delboeuf illusion offers an explanation why people do not fully adjust away from this fill-level anchor and continue to be biased across a large range of dishware sizes. These findings have surprisingly wide-ranging win-win implications for the welfare of consumers as well as for food service managers, restaurateurs, packaged goods managers, and public policy officials.

Original languageEnglish
Pages (from-to)320-332
Number of pages13
JournalJournal of experimental psychology-Applied
Volume19
Issue number4
DOIs
Publication statusPublished - Dec-2013

Keywords

  • optical illusions
  • consumption norms
  • Delboeuf
  • serving size
  • plate size
  • food waste
  • DELBOEUF ILLUSIONS
  • BRIGHTNESS CONTRAST
  • VISUAL ILLUSIONS
  • EATING BEHAVIOR
  • VOLUME
  • ASSIMILATION
  • CONSUMERS
  • INCREASE
  • OBESITY
  • CONTOUR

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