Supermarket Labelling and Taxation Study

NCT07339982 | Recruiting

• 1 other identifier: Supermarket label & tax study
• Study Type: interventional
• Target: 600
• Locations: 1 country
• Sites: 1

Brief Summary

Participants will be assigned to one of four conditions: (i) nutrient warning labelling and no taxation, (ii) nutrient warning labelling and taxation, (iii) current traffic light labelling and taxation or (iv) a control condition (current traffic light labelling and no taxation). Participants will complete a food ordering task using a simulated online supermarket resembling a major UK retailer (Tesco), before purchasing their selected items for delivery/collection via the retailer. Food choices will be recorded, and participants will self-report intake of purchased food items.

Conditions

Nutrition Labeling; Tax Policy

Keywords

front-of-pack labelling; nutrition labelling; traffic light label; nutrient warning label; taxation; food choice

Outcome Measures

Primary Outcomes (2)

• Nutritional quality of food order

  The nutritional quality of the participant's full food order will be calculated using mean-weighted UK Nutrient Profiling Model (NPM) scores (32). NPM scores are calculated by subtracting the total value of positive nutrients (fruit, vegetables \& nuts, fibre, protein) from the total value of negative nutrients (calories, saturated fat, sugar, salt). Lower scores indicate better nutritional quality. To account for multiple items being selected, we will calculate a mean NPM score, weighted by the energy content of individual food items. This will be done using the 'weighted.mean' function in R (33) grouped by participant so the weights are specific to individual orders.

  Survey 1, immediately after the intervention.

• Likelihood of purchasing a less healthy option

  Any participants who select a less healthy item (high in at least one nutrient/energy) as part of their meal will be coded as 1, and participants who have only selected options that are not 'high in' will be coded as 0.

  Survey 1, immediately after the intervention.

Secondary Outcomes (2)

• Number of additional items purchased

  Survey 1, immediately after the intervention.

• Total energy and other nutrient intake

  Survey 2, administered the morning after the Tesco order is consumed. Measured between 24 hours and one week post-intervention, depending on the scheduling of the order.

Other Outcomes (8)

• Pre-meal energy and nutrient intake

  Survey 2, administered the morning after the Tesco order is consumed. Measured between 24 hours and one week post-intervention, depending on the scheduling of the order.

• Label awareness

  Survey 1, immediately after the intervention.

• Price awareness

  Survey 1, immediately after the intervention.

Study Arms (4)

Nutrient warning label + no tax

EXPERIMENTAL

Behavioral: Labelling

Nutrient warning label + tax

EXPERIMENTAL

Behavioral: Labelling; Behavioral: Taxation

Traffic light label + tax

EXPERIMENTAL

Behavioral: Labelling; Behavioral: Taxation

Traffic light label + no tax

ACTIVE COMPARATOR

Behavioral: Labelling

Interventions

Labelling BEHAVIORAL

Participants are shown food products displaying front-of pack nutrition labels (nutrient warning labels on products high in calories, saturated fat, salt, and/or sugar/traffic light labels) during a hypothetical food choice task.

Nutrient warning label + no tax; Nutrient warning label + tax; Traffic light label + no tax; Traffic light label + tax

Taxation BEHAVIORAL

Food prices displayed in the hypothetical food choice task include a 20% added tax on products high in calories, saturated fat, salt, and/or sugar.

Nutrient warning label + tax; Traffic light label + tax

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Are a UK resident
• Are aged 18 years and above
• Are fluent in English
• Have access to a laptop/desktop computer with internet access
• Are willing to order, pay for, and eat a ready meal from Tesco for an evening meal
• Can access Home Delivery/Whoosh/Click \& Collect from Tesco
• Do not have any major dietary restrictions (e.g., vegetarian, vegan, gluten-free)
• Are not on any medication which affects appetite
• Do not have a current or past eating disorder diagnosis

Sponsors & Collaborators

• University of Liverpool: lead
• Medical Research Council: collaborator

Study Sites (1)

Online (UK-wide) - Qualtrics

Liverpool, United Kingdom

RECRUITING

MeSH Terms

Interventions

Taxes

Intervention Hierarchy (Ancestors)

Economics; Health Care Economics and Organizations

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor Eric Robinson

Model Details: A 2x2 (labelling and taxation) design in which participants will be assigned to one of four conditions: (i) nutrient warning labelling and no taxation, (ii) nutrient warning labelling and taxation, (iii) current traffic light labelling and taxation or (iv) a control condition (current traffic light labelling and no taxation).

Study Record Dates

• First Submitted: December 19, 2025
• First Posted: January 14, 2026
• Study Start: February 2, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: May 6, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: The IPD and supporting information will be made available upon submission of the manuscript to a journal.
• Access Criteria: Any interested researchers will be able to access the anonymised dataset on the Open Science Framework.

Locations

GB (1)