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.