Value for money or making the healthy choice: the impact of proportional pricing on consumers' portion size choices.
BACKGROUND
Large food portion sizes are determinants of a high caloric intake, especially if they have been made attractive through value size pricing (i.e. lower unit prices for large than for small portion sizes). The purpose of the two questionnaire studies that are reported in this article was to assess the impact of proportional pricing (i.e. removing beneficial prices for large sizes) on people's portion size choices of high caloric food and drink items.


METHODS
Both studies employed an experimental design with a proportional pricing condition and a value size pricing condition. Study 1 was conducted in a fast food restaurant (N = 150) and study 2 in a worksite cafeteria (N = 141). Three different food products (i.e. soft drink, chicken nuggets in study 1 and a hot meal in study 2) with corresponding prices were displayed on pictures in the questionnaire. Outcome measures were consumers' intended portion size choices.


RESULTS
No main effects of pricing were found. However, confronted with proportional pricing a trend was found for overweight fast food restaurant visitors being more likely to choose small portion sizes of chicken nuggets (OR = 4.31, P = 0.07) and less likely to choose large soft drink sizes (OR = 0.07, P = 0.04).


CONCLUSIONS
Among a general public, proportional pricing did not reduce consumers' size choices. However, pricing strategies can help overweight and obese consumers selecting appropriate portion sizes of soft drink and high caloric snacks. More research in realistic settings with actual behaviour as outcome measure is required.
Vermeer
Willemijn M
WM
Institute for Health Sciences, VU University Amsterdam, The Netherlands. willemijn.vermeer@falw.vu.nl
Alting
Esther
E
Steenhuis
Ingrid H M
IH
Seidell
Jacob C
JC
D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D003365:Costs and Cost Analysis; D004435:Eating; D002149:Energy Intake; D057140:Fast Foods / Q000191:economics*; D006801:Humans; D009426:Netherlands; D012147:Restaurants; D011795:Surveys and Questionnaires