Supermarket nutrition labels and taxes to influence shoppers' choices
The Effect of Nutrient Warning vs. Traffic Light Labels and Taxation on Food Purchasing Behaviour Among UK Consumers: a Randomised Controlled Trial
We're testing whether adding warning labels and a 20% tax on foods high in saturated fat, sugar, salt, or calories changes what UK adults buy in a simulated online supermarket.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 600 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | University of Liverpool Academic / other |
| Locations | 1 site (Liverpool) |
| Trial ID | NCT07339982 on ClinicalTrials.gov |
What this trial studies
This randomized 2x2 online experiment assigns UK adults to one of four conditions combining front-of-pack labelling (nutrient warning versus current traffic-light) and pricing (20% tax versus no tax). Participants complete a simulated Tesco online shopping task, purchase selected ready meals for delivery or collection, and self-report intake of the items they bought. Products that exceed defined thresholds for saturated fat, sugar, salt, or calories receive warning labels and, in taxed conditions, a 20% price increase. The trial records food choices and reported consumption to measure the independent and combined effects of labelling and taxation on purchases and intake.
Who should consider this trial
Good fit: Ideal participants are UK residents aged 18 or older who speak English, have access to a laptop or desktop with internet, can order and receive (or collect) a Tesco ready meal, and do not have major dietary restrictions, appetite-altering medications, or a current/past eating disorder.
Not a fit: People outside the UK, without access to Tesco delivery/collection or a computer, with major dietary restrictions, on medications that affect appetite, or with a history of eating disorders are unlikely to be eligible or to benefit.
Why it matters
Potential benefit: If effective, this approach could reduce purchases of unhealthy products and lower calorie and harmful nutrient intake across the population.
How similar studies have performed: Previous real-world and experimental work on front-of-pack warning labels and taxes on sugary drinks has shown reductions in purchases of unhealthy products, though combining warning labels with a broad 20% tax on multiple high-nutrient items is less commonly tested.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 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
Where this trial is running
Liverpool
- Online (UK-wide) - Qualtrics — Liverpool, United Kingdom (Recruiting)
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.