Does wine glass size influence sales for on-site consumption? A multiple treatment reversal design.
Wine glass size can influence both perceptions of portion size and the amount poured, but its impact upon purchasing and consumption is unknown. This study aimed to examine the impact of wine glass size on wine sales for on-site consumption, keeping portion size constant.



In one establishment (with separate bar and restaurant areas) in Cambridge, England, wine glass size (Standard; Larger; Smaller) was changed over eight fortnightly periods. The bar and restaurant differ in wine sales by the glass vs. by the bottle (93 % vs. 63 % by the glass respectively).



Daily wine volume purchased was 9.4 % (95 % CI: 1.9, 17.5) higher when sold in larger compared to standard-sized glasses. This effect seemed principally driven by sales in the bar area (bar: 14.4 % [3.3, 26.7]; restaurant: 8.2 % [-2.5, 20.1]). Findings were inconclusive as to whether sales were different with smaller vs. standard-sized glasses.



The size of glasses in which wine is sold, keeping the portion size constant, can affect consumption, with larger glasses increasing consumption. The hypothesised mechanisms for these differential effects need to be tested in a replication study. If replicated, policy implications could include considering glass size amongst alcohol licensing requirements.



ISRCTN registry: ISRCTN12018175 . Registered 12(th) May 2015.
Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
Rachel
R
Pechey
Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
Dominique-Laurent
DL
Couturier
Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
Gareth J
GJ
Hollands
Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
Eleni
E
Mantzari
MRC Integrative Epidemiology Unit (IEU), UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, Bristol, UK.
Marcus R
MR
Munafò
Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK. tm388@cam.ac.uk.
Theresa M
TM
Marteau
D000428:Alcohol Drinking / Q000517:prevention & control* / Q000523:psychology; D003132:Commerce / Q000706:statistics & numerical data; D004739:England; D005898:Glass; D006801:Humans; D064787:Portion Size; D012147:Restaurants / Q000191:economics*; D014920:Wine
Alcohol; Choice architecture; Glass size; Sales