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The Effect of a Descriptive Norm Promoting Vegetable Selection in a Workplace Restaurant Setting: an Observational Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02603263
Recruitment Status : Completed
First Posted : November 11, 2015
Last Update Posted : November 11, 2015
Economic and Social Research Council, United Kingdom
C H & Co Ltd.
Information provided by (Responsible Party):
University of Birmingham

Brief Summary:
Encouraging individuals to eat fruit and vegetables is difficult. However, recent evidence suggests that using social-based information might help. For instance, it has been shown that if people think that others are eating lots of fruit and vegetables, that they will consume more food to match the 'norm'.The purpose of this study was to determine whether social norm messages could be used to enhance vegetable purchases in workplace restaurants, in an observational study.

Condition or disease Intervention/treatment
Eating Behaviour Other: Social Norms Poster

Detailed Description:
In this study the investigators hypothesised that placing posters containing social norm messages promoting vegetable consumption in three workplace restaurants, would increase the purchase of meals with vegetables, and that this effect would be sustained over time. The investigators recruited three restaurants to this study. For two weeks (Pre-intervention phase) the investigators used till receipts to monitor the number of meals sold with or without vegetables at baseline. For the following two weeks (Intervention phase) the investigators placed social norms posters around the three restaurants, while continuing to collect till receipts. After this, the posters were removed, and receipts were monitored for a final two weeks (Post-intervention).

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Study Type : Observational
Actual Enrollment : 9445 participants
Official Title: The Effect of a Descriptive Norm Promoting Vegetable Selection in a Workplace
Study Start Date : February 2015
Actual Primary Completion Date : August 2015
Actual Study Completion Date : August 2015

Group/Cohort Intervention/treatment
Workplace Restaurant Customers

1 Group (Workplace Restaurant Customers) across 3 sites (data to be combined at end of study)

Study consists of three phases:

  1. Pre Intervention
  2. Intervention
  3. Post Intervention

All phases lasted two weeks and included monitoring till receipts for meals (these were automatically generated and held on the tills electronically). The intervention phase consisted of posters being displayed in the restaurants, featuring a Social Norms Poster.

Other: Social Norms Poster
A poster containing a social norms message: "Most people here choose to eat vegetables with their lunch"

Primary Outcome Measures :
  1. Percentage of meals containing vegetables [ Time Frame: 7 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Customers at workplace restaurants.

Inclusion Criteria:

  • Purchase of a meal at one of the restaurants

Exclusion Criteria:

  • None

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02603263

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United Kingdom
University of Birmingham
Birmingham, West Midlands, United Kingdom, B15 2TT
Sponsors and Collaborators
University of Birmingham
Economic and Social Research Council, United Kingdom
C H & Co Ltd.
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Principal Investigator: Jason M Thomas, PhD University of Birmingham
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: University of Birmingham Identifier: NCT02603263    
Other Study ID Numbers: UBirmingham-SNS7
First Posted: November 11, 2015    Key Record Dates
Last Update Posted: November 11, 2015
Last Verified: November 2015
Keywords provided by University of Birmingham:
social norms
healthy eating
field study