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 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | Pre.2020.030 |
| Sponsor | University of Cambridge |
| Funder | Wellcome Trust |
- 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
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
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 ID |
0000-0002-6558-388X |
|---|---|
| rachel.pechey@phc.ox.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Single-centre two-group between-subjects design |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Increasing the relative availability of healthier vs. less healthy food: Can impact be explained in terms of prior preferences? A follow-up pilot study |
| Study objectives | Vegetarian 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) studied | Unhealthy diet |
| Intervention | 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 (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 type | Behavioural |
| Primary outcome measure(s) |
The ranking score calculated for each meal option following completion of the online survey (single timepoint) |
| Key secondary outcome measure(s) |
There are no secondary outcome measures |
| Completion date | 31/07/2020 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | All |
| Target sample size at registration | 540 |
| Total final enrolment | 540 |
| Key inclusion criteria | 1. Adults aged over 18 years 2. Participants currently residing within the UK |
| Key exclusion criteria | Dietary restrictions |
| Date of first enrolment | 15/04/2020 |
| Date of final enrolment | 30/04/2020 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Institute of Public Health
University Forvie Site
Robinson Way
Cambridge
CB2 0SR
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| IPD sharing plan | The 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 | |
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
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.
