Plain English Summary
Background and study aims:
Many people exercise because they know it is good for their health. Although this is true, it can make us feel deserving of a reward and lead us to eat more indulgent, less healthy food than if we had not done any exercise. Generally, lower energy-dense (LED) foods are recognised as healthier choices than higher energy-dense (HED) options. Despite our intention to make healthy choices, seeing tempting higher-calorie foods on offer often side-tracks us. Priming is a psychological tool that makes specific changes to our environment that remind us of our motivation to be healthy. This makes it easier to choose a healthier option, by nudging us towards it without us even realising. Our study explores whether priming people to expect they will receive LED food leads them to make this healthier choice after exercise, even when also offered tempting less healthy HED foods at the moment of selection.
Who can participate?
Potential participants must be members of the University of St Andrews 1st or 2nd XI, male or female, football or hockey teams.
What does the study involve?
All participants complete three questionnaires: baseline, pre-match and post-match. In the pre-match questionnaire, only experimental group participants are supraliminally primed to select a low energy-dense food for post-exercise consumption. After the sports match (and post-match questionnaire completion), all participants are select one food item from three low energy-dense and three high energy-dense foods on offer. The frequency of low versus high-energy dense food selection between control and experimental groups is compared.
What are the possible benefits and risks of participating?
When participants are made aware of the study focus upon receiving the Participant Debrief Form, this knowledge may increase their awareness of the healthfulness of food choices after exercise and subsequently nudge them towards making healthier future choices.
The only potential risk is that of food allergies, hence we advise all participants to carefully consider this risk before participating. Foods provided avoided containing common allergens and all ingredient labels were clearly visible.
Where is the study run from?
University of St Andrews School of Medicine (Population and Behavioural Sciences division)
When is the study starting and how long is it expected to run for?
March 2019 to February 2020
Who is funding the study?
This study was funded by the University of St Andrews (UK)
Who is the main contact?
To what extent does priming individuals to select low energy-dense (LED) foods reduce their selection of high energy-dense (HED) items when faced with the temptation of more calorically dense visual cues?
Supraliminal priming increases individuals' tendency to select less energy-dense foods, rather than high energy-dense foods following exercise (compared to a control group not receiving a priming intervention).
Approved 17/01/2020, University of St Andrews School of Medicine Research Ethics Committee (University of St Andrews School of Medicine, North Haugh, St Andrews, KY16 9TF, UK; +44 (0)1334 461733; no email provided), ref: MND14700
Single-center interventional single-blinded randomized controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
See additional files
Promotion of less energy-dense food selection following exercise in university-level student athletes, as part of promotion of an overall healthier lifestyle.
Computer-generated randomisation into control and experimental groups.
All participants complete three questionnaires: baseline (one week before participants' sports match), pre-match (within one hour before the match) and post-match (immediately following the match).
Control group: no priming intervention applied.
Experimental group: The priming intervention is one question in the pre-match questionnaire, which asks participants to select a low energy-dense food for post-match consumption.
Post-match, following questionnaire completion, all participants are asked to select one food item from a selection of three low energy-dense and three high energy-dense foods visually displayed on offer (much to the surprise of the experimental group who have been primed to expect a choice of exclusively low energy-dense options).
Primary outcome measure
Energy density of food item selected is measured by the researcher observing whether participants select a low energy-dense or high energy-dense food following post-match questionnaire completion (immediately following participants' sports match)
Secondary outcome measures
Self reported appetite is measured using a visual analogue scale (0-10) before exercise (pre-match questionnaire) and after exercise (post-match questionnaire)
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Members of the University of St Andrews 1st or 2nd XI, male or female, football or hockey teams.
Target number of participants
Total final enrolment
Participant exclusion criteria
Does not meet inclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University of St Andrews Sports Centre
St Leonard's Rd
University of St Andrews
Funding Body Type
private sector organisation
Funding Body Subtype
Universities (academic only)
Results and Publications
Publication and dissemination plan
This study is currently in the process of submission to the BMC Psychology journal.
IPD sharing statement:
All data generated or analysed during this study will be included in the subsequent results publication.
Intention to publish date
Participant level data
Basic results (scientific)
- ISRCTN74601698_PIS_v1.1_14Nov2019.pdf Uploaded 08/10/2020