Does the size of wine glasses influence how much wine is sold in bars or restaurants?

ISRCTN ISRCTN12018175
DOI https://doi.org/10.1186/ISRCTN12018175
Secondary identifying numbers N/A
Submission date
27/04/2015
Registration date
12/05/2015
Last edited
14/06/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Mental and Behavioural Disorders
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims.
Previous research has suggested that people’s perceptions of the portion size of wine are influenced by the size of the wine glass (with the same given volume of wine perceived as less in larger glasses than in smaller glasses), but it is not clear whether glass size can also affect the amount of wine that is purchased or consumed. The aim of the current study is to examine the impact of the size of wine glasses on wine purchasing, and in particular to test the hypothesis that sales of wine will decrease with decreasing wine glass size.

Who can participate?
One independent bar/restaurant in Cambridge UK is participating in the study. Data will be based on customers visiting the restaurant during the 10-week study period.

What does the study involve?
At one independent bar/restaurant, we first replace the standard wine glasses (30 cl glasses) used with larger (37 cl) for a period of two weeks. The standard size wine glass is then used again for the next two weeks. From week 6 to 8 smaller (25 cl) glasses are used. Finally, the standard wine glasses are used for the last two weeks of the study. We compare sales of wine at the beginning of the study with sales when using each glass size.

What are the possible benefits and risks of participating?
We consider this study to be low risk. We do not expect any adverse consequences associated with taking part in the study. The findings from this study will generate preliminary evidence of the impact of the size of wine glasses on purchasing of wine.

Where is the study run from?
Testing will take place in one independent bar/restaurant in Cambridge (UK). The study is run from the Behaviour and Health Research Unit at the University of Cambridge (UK).

When is the study starting and how long is it expected to run for?
March 2015 to June 2015.

Who is funding the study?
Department of Health Policy Research Programme (Policy Research Unit in Behavior and Health [PR-UN-0409-10109])

Who is the main contact?
Professor Theresa Marteau
tm388@cam.ac.uk

Contact information

Dr Theresa Marteau
Scientific

Behaviour and Health Research Unit
University of Cambridge
Institute of Public Health
Forvie Site
Cambridge
CB2 0SR
United Kingdom

Phone +44 (0)1223 330331
Email tm388@cam.ac.uk

Study information

Study designThe study will use a multiple treatment reversal design, conducted in an outlet that functions as both a bar and restaurant, with each of five periods lasting two weeks: A: Baseline: standard 30 cl glass in use B: Larger 37 cl glass to replace standard glass A: Standard 30 cl glass in use C: Smaller 25 cl glass to replace standard glass A: Standard 30 cl glass in use 20/10/2015: Following discussion with the participating outlet, the decision was taken to extend the study so as to have two fortnightly periods where each of the intervention glasses were used, i.e. eight periods lasting two weeks: A: Baseline: standard 30 cl glass in use B: Larger 37 cl glass to replace standard glass A: Standard 30 cl glass in use C: Smaller 25 cl glass to replace standard glass B: Larger 37 cl glass to replace standard glass A: Standard 30 cl glass in use C: Smaller 25 cl glass to replace standard glass A: Standard 30 cl glass in use
Primary study designInterventional
Secondary study designMultiple treatment reversal design
Study setting(s)Community
Study typePrevention
Scientific titleDoes size of wine glasses impact on on-licence sales? An experimental study using a multiple treatment reversal design.
Study objectivesThe impact on purchasing and consumption of altering the size of glasses in which alcohol is served is uncertain. The aim of the current study is to examine the impact of the size of wine glasses on wine purchasing, and in particular, to test the hypothesis that sales of wine will decrease with decreasing wine glass size. The specific study hypothesis is: Sales of wine when using 37 cl glasses will be higher than sales of wine when using 30 cl glasses, which will be higher than sales of wine when using 25 cl glasses
Ethics approval(s)University of Cambridge Psychology Research Ethics Committee, 27/01/2015, ref: Pre.2014.127
Health condition(s) or problem(s) studiedAlcohol consumption, which is ranked 5th amongst the 20 leading risk factors for burden of disease in the UK.
InterventionReplacing the wine glasses used in an outlet selling wine to compare baseline sales of wine (i.e. when using the outlet’s standard glasses) to sales when using larger and smaller glasses.
The current standard glasses used in the target outlet have a capacity of 30cl. The replacements are:
1. Smaller: 25cl glass, of same design as the standard glass
2. Larger: 37cl glass of same design as the standard glass
Each replacement will last two weeks and will be interceded by a two-week return to use of the outlet’s standard glasses.
Intervention typeBehavioural
Primary outcome measureThe daily volume of wine purchased in each intervention period compared to baseline.
Secondary outcome measuresN/A
Overall study start date15/03/2015
Completion date30/09/2015

Eligibility

Participant type(s)Other
Age groupNot Specified
SexNot Specified
Target number of participantsOne independent bar/restaurant in Cambridge, UK is participating in the study. Data will be based on purchases made by thousands of customers (18 years and over) visiting the restaurant during the study period and ordering wine.
Key inclusion criteriaEnglish outlets serving wine
Key exclusion criteriaN/A
Date of first enrolment15/03/2015
Date of final enrolment30/06/2015

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Behaviour and Health Research Unit
University of Cambridge
Institute of Public Health
Forvie Site
Cambridge
CB2 0SR
United Kingdom

Sponsor information

University of Cambridge (UK)
University/education

Research Operations Office
School of Clinical Medicine
Addenbrooke's Hospital, Box 111
Hills Road
Cambridge
CB2 0SP
England
United Kingdom

ROR logo "ROR" https://ror.org/013meh722

Funders

Funder type

Government

Department of Health Policy Research Programme (UK)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planWe plan and write up our findings and submitting them to a scientific journal for peer review and publication. The expected date for this is August 2015.
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 07/06/2016 Yes No
Other publications Replication study 01/08/2017 14/06/2023 Yes No

Editorial Notes

14/06/2023: Publication reference added.
07/06/2016: Publication reference added.
20/10/2015: Study design has been modified at the trialist's request.