Food Choice Among Individuals With an Eating Disorder Diagnosis

The Impact of Warning Labels vs Traffic Light Labels on Food Choice and Negative Emotional Response in an Eating Disorder Population Group

The aim of this study is to understand the impact of front of pack labelling systems such as, warning labels and traffic light labels on food choice and negative emotional response in an eating disorder(s) population group. Participants will be recruited to take part in an online study where they will be required to make hypothetical food choices. Participants will complete a baseline no label task, before being randomly assigned to (1) warning label group, (2) traffic light label group, or (3) no label group in which they will complete the same task a second time (mixed design). Each participant, irrespective of the group will be asked to complete five trials within the main task. Participants will view a selection of six packaged food items for scenarios involving labels predominately relating to (1) sugar, (2) salt, (3) fat, (4) saturated fat, and (5) calorie content of the food products. Three items will be 'high in' that particular nutrient and three items will not be high in that nutrient. Participants will be shown all six options at once and will be asked to choose one item. In total, participants will choose five different items, one from each trial. After participants have made their food choices for the second task, they will be asked questions about the task they have just completed.

Study Overview

• Status: Recruiting
• Conditions: Eating Behavior Disorders
• Intervention / Treatment: Behavioral: Front-of-pack nutrition labelling

Detailed Description

The aim of this study is to understand the impact of front of pack labelling systems such as, warning labels and traffic light labels on food choice and negative emotional response in an eating disorder(s) population group.

Hypotheses:

Both WL and TLL will affect food choice (vs. control), but WL will have a larger impact on discouraging unhealthy food choices than TLL.

Both WL and TLL will affect calorie and nutrient selected (vs. control), but WL will have a larger impact than TLL.

WL will have a larger impact on negative emotional responses than TLL.

Study type:

Randomised controlled trial (RCT).

Blinding:

Participants will not know the group to which they have been assigned to.

Additional blinding:

Participants will be given to a cover story to conceal the objectives of the study.

Study design:

Participants will be recruited to take part in an online study where they will be required to make hypothetical food choices. Participants will complete a baseline no label task, before being randomly assigned to (1) warning label group, (2) traffic light label group, or (3) no label group in which they will complete the same task a second time (mixed design).The baseline task must be completed between 24 hours and 1 week prior to completing the second task. Each participant, irrespective of the group will be asked to complete five trials within the main task. Participants will view a selection of six packaged food items for scenarios involving labels predominately relating to (1) sugar, (2) salt, (3) fat, (4) saturated fat, and (5) calorie content of the food products. Three items will be 'high in' that particular nutrient and three items will not be high in that nutrient. Participants will be shown all six options at once and will be asked to choose one item. In total, participants will choose five different items, one from each trial. After participants have made their food choices for the second task, they will be asked questions about the task they have just completed. All tasks and questionnaires will be identical in each label group - only the label will differ.

Food choice task Qualtrics XM survey software will be used to create the different trials within the food choice task. Participants will be recruited through Prolific; a data collection platform which recruits participants for online studies globally. Participants earn money by completing studies proportionate to the time it takes to complete the study (around £6 per hour). An online information sheet and consent form will be automatically displayed to participants via Qualtrics before the survey starts. Participants will be required to confirm that they have read the information sheet, and consent to taking part, in order to gain access to the survey questions. The survey will take approximately 15 minutes. Upon completion/termination of the survey, an online debrief sheet, including links to where they can be directed to for help if the study has triggered symptoms, will be automatically displayed to participants via Qualtrics.

Participants will be told to imagine they are hypothetically choosing different items for themselves to eat. The task will include 5 trials (1) crisps, (2) cereal, (3) pasta ready meal, (4) assorted savoury snacks, and (5) lunch salads. Each trial will focus on a different 'high in' nutrient, for example, (1) crisps will display 'high in salt', (2) cereals will display 'high in sugar', (3) pasta ready meals will display 'high in saturated fat', (4) assorted savoury snacks will display 'high in fat', and (5) lunch salads will display 'high in calories'. In each trial there will be three packaged food items without 'high in' labels or a 'red' traffic light label and three with WL or TLL (see "Label task questionnaire" attachment). Criteria for products labelled 'high in' is in line with labelling criteria for TLL in the UK. The design of WL will be representative of the results from patient and public involvement (PPI) from a study co-designing and examining 'high in' warning labels for a selection of food items and menu items in the UK. The design of TLL will be as it exists on UK products currently. Packaged products were selected from Tesco online supermarket. In the WL group, all TLL will be hidden. Products will be kept as similar as possible within each trial, for example, all cereals were chocolate flavoured, all crisps salt and vinegar flavoured. Pricing will not be displayed to prevent price influencing food choice.

• Study Type: Interventional
• Enrollment (Estimated): 246
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rebecca Evans, PhD; Phone Number: 0151 794 9832; Email: r.k.evans@liverpool.ac.uk
• Study Contact Backup: Name: Rebecca Latham, MSc; Phone Number: 0151 794 9832; Email: Rebecca.Latham@liverpool.ac.uk

Study Locations

• United Kingdom
  • Liverpool, United Kingdom, L17 1AJ
    • Recruiting
    • University of Liverpool
    • Contact: Rebecca Evans, PhD; Phone Number: 0151 794 9832; Email: r.k.evans@liverpool.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Current or past eating disorder diagnosis
• Aged 18+
• Live in the UK
• Fluent English speaker

Exclusion Criteria:

• Currently partaking in a fast or any other restrictive eating
• Any dietary restrictions/intolerances (eg. Vegan, Gluten-free, etc.)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: No label; Products in the food choice task will not feature a nutrition label.	Behavioral: Front-of-pack nutrition labelling; Participants will view a selection of six packaged food items for scenarios involving labels predominately relating to (1) sugar, (2) salt, (3) fat, (4) saturated fat, and (5) calorie content of the food products. Three items will be 'high in' that particular nutrient and three items will not be high in that nutrient. Participants will be shown all six options at once and will be asked to choose one item. In total, participants will choose five different items, one from each trial.
Experimental: Traffic light label; Products in the food choice task will feature a traffic light label.	Behavioral: Front-of-pack nutrition labelling; Participants will view a selection of six packaged food items for scenarios involving labels predominately relating to (1) sugar, (2) salt, (3) fat, (4) saturated fat, and (5) calorie content of the food products. Three items will be 'high in' that particular nutrient and three items will not be high in that nutrient. Participants will be shown all six options at once and will be asked to choose one item. In total, participants will choose five different items, one from each trial.
Experimental: Warning labels; Products in the food choice task will feature warning labels if high in sugar, salt, fat, saturated fat, and/or calories.	Behavioral: Front-of-pack nutrition labelling; Participants will view a selection of six packaged food items for scenarios involving labels predominately relating to (1) sugar, (2) salt, (3) fat, (4) saturated fat, and (5) calorie content of the food products. Three items will be 'high in' that particular nutrient and three items will not be high in that nutrient. Participants will be shown all six options at once and will be asked to choose one item. In total, participants will choose five different items, one from each trial.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total number of unhealthy food items selected	Total number of selected unhealthy food items across the 5 trials will be calculated. Unhealthy food items will be coded as items eligible for a WL or a red traffic light label for the task-specific nutrient e.g., red for salt in crisp trial.	Measured in both surveys, immediately after the intervention. The baseline task must be completed between 24 hours and 1 week prior to completing the second task.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total calories, salt, sugar, fat, saturated fat from selected food items	Total number of calories, salt (g), sugar (g), fat (g), saturated fat (g) from selected food items across the 5 trials will be calculated.	Measured in both surveys, immediately after the intervention.
Negative emotional response	To be assessed using an adapted four-item measure, previously used to assess responses to health warning labels regarding snack selection (Clarke et al., 2020). Responses will be conveyed using seven-point scales: 'How afraid/worried/uncomfortable/disgusted does the label on food make you feel about consuming a product? With scores ranging from 1 (not at all afraid/worried/uncomfortable/disgusted) to 7 (very afraid/worried/uncomfortable/disgusted). A mean average will be calculated for the four items.	Measured in survey 2, immediately after the intervention.
Positive and negative affect schedule (PANAS)	Negative affect is to be assessed using the shortened version of PANAS (Mackinnon et al., 1999). Only the 5 items (afraid, upset, nervous, scared, distressed) that assess negative affect will be included pre and post the food choice task, as hypotheses relate to negative affect, whereas positive affect is not anticipated to be impacted by food labelling. 'How afraid/upset/nervous/scared/distressed do you feel right now?' Responses will be conveyed using Likert scale (1=Very slightly or not at all to 5= Extremely) based on the extent of which participant feels that emotion in a particular time frame (e.g., pre task and post task). Pre- and post- food choice task responses will be used to assess whether participants experience a change in negative emotion following exposure to the labels.	Measured in both surveys, pre-intervention and immediately after the intervention.
Reactance and avoidance	Two items will be taken from a 27-item scale developed for reactance to tobacco health warnings that were then used to assess responses to health warning labels regarding snack selection (Hall et al., 2016) (Clarke et al., 2020). Responses will be denoted using seven-point scales. Reactance: 'Are these labels annoying?'. Avoidance: 'Are you likely to avoid these labels?' With scores ranging from 1 (not annoying/not at all) to 7 (extremely annoying/very likely). Items will be scored separately.	Measured in survey 2, immediately after the intervention.
Acceptability of labels	To be assessed using one item with responses represented on a seven point scale, adapted from a similar measure used to assess warning labels on a snack selection (Clarke et al., 2020). 'Do you support or oppose putting this label on food products?'. With scores ranging from 1 (strongly oppose) to 7 (strongly support). A score higher than the midpoint (four) will be taken as acceptability.	Measured in survey 2, immediately after the intervention.
Perceived message effectiveness (PME)	Three items will be adapted and taken from a scale used to predict behaviour change in the context of tobacco (Baig et al., 2018). Responses will be conveyed using a Likert scale ranging from 1-5 (not at all/a great deal). Discouragement: 'This label discourages me from wanting to consume a food product'. Unpleasantness: 'The label makes consuming a food product seem unpleasant'. Concern: 'This label makes me concerned about the health effects of consuming a food product'. The mean response to the three items will be calculated.	Measured in survey 2, immediately after the intervention.
Label awareness	'Did you notice a nutrition label when making your food choices (e.g., when choosing crisps, pasta ready meal, cereal, savoury snacks, and lunch salad?' (yes/no/unsure). If answered yes, what information was included? Response options (shown in random order): high in salt, high in sugar, high in saturated fat, high in fat, high in fibre, high in calories, calorie information, allergen information, none of these, unsure. Participants coded aware if they select all the correct responses.	Measured in survey 2, immediately after the intervention.
Label influence	Did the presence of a nutrition label on the food items influence your food choice? Yes/No/Unsure. If answered yes, how did the nutrition label influence your food choice? Response options (shown in random order): it made me select a healthier food item, it made me avoid items high in fat/saturated fat/salt/sugar, it made me select a less healthier food item, it prompted me to think about my food choice before deciding, it didn't influence me and I ignored it, not sure.	Measured in survey 2, immediately after the intervention.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Aim guessing	Aim-guessing question will be included to help researchers identify whether participants are aware of the true purpose of the study. If participants correctly guess the aim, they may alter their behaviour to align with what they think the researcher expects, introducing bias. One researcher will code awareness of aims and a second researcher will independently verify the coding.	Measured in survey 2, immediately after the intervention.

Collaborators and Investigators

• Sponsor: University of Liverpool
• Collaborators: National Institute for Health Research, United Kingdom
• Investigators: Principal Investigator: Eric Robinson, PhD, University of Liverpool

Study record dates

Study Major Dates

• Study Start (Actual): November 13, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: December 18, 2025
• First Submitted That Met QC Criteria: January 5, 2026
• First Posted (Actual): January 14, 2026

Study Record Updates

• Last Update Posted (Actual): January 14, 2026
• Last Update Submitted That Met QC Criteria: January 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: food choice; eating disorders; warning labels; nutrition labelling; traffic light labels
• Additional Relevant MeSH Terms: Mental Disorders; Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Feeding and Eating Disorders
• Other Study ID Numbers: 15576

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymised dataset will be uploaded to the Open Science Framework.
• IPD Sharing Time Frame: Indefinitely, from the date of article submission.
• IPD Sharing Access Criteria: Any interested researchers can access the anonymised dataset.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No