To what extent can the effects of increasing healthier food availability on food selection be explained by individual food preferences? A follow-up pilot study

ISRCTN ISRCTN15043170
DOI https://doi.org/10.1186/ISRCTN15043170
Secondary identifying numbers Pre.2020.030
Submission date
08/04/2020
Registration date
14/04/2020
Last edited
12/06/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Increasing the availability of healthier or more plant-based foods increases their selection. One possible mechanism that might underlie these effects is individuals’ prior preferences, whereby selections reflect individuals’ most-preferred option from the available range. The first exploration – to the researchers' knowledge – of the role of prior preferences as a possible mechanism underlying the effects of manipulating the relative availability of healthier and less healthy options suggested that a large majority of selections reflect the most-preferred option. However, only small differences were observed in preferences by option healthiness in this initial study. This study aims to further explore role of preferences by identifying high vs. low preference options for use in an extension of the previous study, as well as exploring the extent to which preferences vary depending on whether options are meat-based or vegetarian.

Who can participate?
Adults over the age of 18 with no dietary restrictions

What does the study involve?
The study will be conducted online. Participants will all see meat-based less-healthy meal options, but will be randomly assigned to also see images of either meat-based healthier meal options or vegetarian healthier meal options. The study will establish each participant’s baseline relative preferences between all the food options they have been assigned to in the study. To do so, participants are asked to choose which option they would prefer to eat right now from pairs of food options. These pairs represent every possible pairing of food options assigned in the study. This allows each food option to subsequently be ranked in terms of each participant’s preferences. The data from the study will be used to identify main meal options that represent high vs. low preference options for use in a subsequent extension study, and to examine the extent to which preferences are altered depending on whether options are meat-based or vegetarian.

What are the possible benefits and risks of participating?
Participants will be paid the equivalent of UK minimum wage for participating in the study. There are no known risks of participating.

Where is the study run from?
Behaviour and Health Research Unit, University of Cambridge (UK)

When is the study starting and how long is it expected to run for?
February 2020 to July 2020

Who is funding the study?
Wellcome Trust (UK)

Who is the main contact?
Dr Rachel Pechey
rachel.pechey@phc.ox.ac.uk
(updated 07/01/2021, previously: rachel.pechey@medschl.cam.ac.uk)

Contact information

Dr Rachel Pechey
Scientific

Nuffield Department of Primary Care Health Sciences
University of Oxford
Radcliffe Primary Care Building
Radcliffe Observatory Quarter
Woodstock Rd
Oxford
OX2 6GG
United Kingdom

ORCiD logoORCID ID 0000-0002-6558-388X
Email rachel.pechey@phc.ox.ac.uk

Study information

Study designSingle-centre two-group between-subjects design
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Internet/virtual
Study typeOther
Participant information sheet Not available in web format, please use the contact details to request a participant information sheet
Scientific titleIncreasing the relative availability of healthier vs. less healthy food: Can impact be explained in terms of prior preferences? A follow-up pilot study
Study objectivesVegetarian options are less likely to be selected than comparable meat-based options.
Ethics approval(s)Approved 30/03/2020, Cambridge Psychology Research Ethics Committee (School of the Biological Sciences, 17 Mill Lane, Cambridge, CB2 1RX, UK; +44 (0)1223 766894; Cheryl.torbett@admin.cam.ac.uk), ref: Pre.2020.030
Health condition(s) or problem(s) studiedUnhealthy diet
InterventionThe study will be conducted online. Participants will all see meat-based less-healthy meal options, but will be randomly assigned to also see images of either meat-based healthier meal options or vegetarian healthier meal options. The study will establish each participant’s baseline relative preferences between all the food options they have been assigned to in the study. To do so, participants are asked to choose which option they would prefer to eat right now from pairs of food options. These pairs represent every possible pairing of food options assigned in the study. This allows each food option to subsequently be ranked in terms of each participant’s preferences. The data from the study will be used to (1) identify main meal options that represent high vs. low preference options for use in a subsequent extension study, and (2) to examine the extent to which preferences are altered depending on whether options are meat-based or vegetarian.
Intervention typeBehavioural
Primary outcome measureThe ranking score calculated for each meal option following completion of the online survey (single timepoint)
Secondary outcome measuresThere are no secondary outcome measures
Overall study start date01/02/2020
Completion date31/07/2020

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants540
Total final enrolment540
Key inclusion criteria1. Adults aged over 18 years
2. Participants currently residing within the UK
Key exclusion criteriaDietary restrictions
Date of first enrolment15/04/2020
Date of final enrolment30/04/2020

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

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

Sponsor information

University of Cambridge
University/education

Greenwich House
Madingley Rd
Cambridge
CB3 0TX
England
United Kingdom

Phone +44 (0)1223333543
Email research_governance@medschl.cam.ac.uk
Website http://www.cam.ac.uk/
ROR logo "ROR" https://ror.org/013meh722

Funders

Funder type

Research organisation

Wellcome Trust
Private sector organisation / International organizations
Location
United Kingdom

Results and Publications

Intention to publish date31/12/2020
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination plan1. Planned submission of the main results of this study for publication in a peer-reviewed journal
2. Dissemination of the results to the public, policy makers and other researchers through targeted social media
IPD sharing planThe data-sharing plans for the current study are unknown and will be made available at a later date.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 26/01/2021 12/06/2023 Yes No

Editorial Notes

12/06/2023: Publication reference added.
07/01/2021: The following changes were made to the trial record:
1. The contact details were updated.
2. The plain English summary was updated to reflect these changes.
20/05/2020: The total final enrolment number has been added.
14/04/2020: Trial's existence confirmed by the Wellcome Trust.