A multicomponent evaluation of new restrictions on marketing of less healthy foods in England
| ISRCTN | ISRCTN72442267 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN72442267 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | Nil known |
| Sponsor | University of Cambridge |
| Funder | National Institute for Health and Care Research |
- Submission date
- 22/10/2025
- Registration date
- 23/10/2025
- Last edited
- 13/11/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Other
Plain English summary of protocol
Background and study aims
In the UK, many people do not eat in ways that best supports their health. One reason for this is food marketing. Food marketing includes adverts on TV and online as well as special offers. Food marketing mostly focuses on less healthy things like fast food and sweets.
In October 2025, new rules will ban special offers on less healthy food and drinks (eg 3-for-2 offers), TV adverts for these items from 5.30am to 9pm and some online ads . A standard definition of ‘less healthy’ will be used.
The effects of these bans could extend beyond what food and drinks are marketed. For example, companies may start making healthier food to avoid the bans. Or peoples’ buying habits may change, with an impact on the health of the population and economy.
We aim to understand the impacts of the bans on health, the economy and society. This will inform future government policy.
Who can participate?
Much of our work will not involve participants but instead will use information on things like what products are available in supermarkets and what products are advertised on TV and online.
What does the study involve?
We will first study impacts on food marketing. We will use data collected by market research companies and by us and compare the year before the bans to the year after. We will study whether special offers on less healthy items become less common, whether healthier items become more available, and how TV and online advertising changes. We will use data on grocery purchases from 30,000 households to study changes in buying habits.
We have already developed a method to predict changes in chronic diseases from changes in food purchasing. We will use this to predict changes in weight, diabetes, heart disease and cancer over 10 years. We will also study any changes in costs to the NHS of treating these conditions.
The bans could lead to loss of employment in food, media and advertising. We will track the economic performance of relevant companies in the year before the bans compared to the year after.
We will then combine results from all our work to estimate the impacts of the bans on society. We will balance impacts on health and the NHS with those on the economy.
The bans might not work as intended. We will run focus groups and surveys to understand how parents and youth experience the bans. Interviews with people from government and the private sector will help us understand what did and didn't go well.
There are four components where participants will be involved:
1. We will purchase data from a market research company on household food purchasing. This company collects information from around 30,000 UK households every week on what food they brought into their homes. We will study trends in purchases of less healthy foods from 2024 – 2026.
2. We will use answers to an annual online questionnaire collected by colleagues in Canada on how much food marketing people have seen and how much they support the bans. Each year around 4000 adults and 1500 youth from each of the UK, Australia , Canada, Mexico and the USA take part in online surveys and we will compare findings from 2024, 2025 and 2026.
3. We will also study how much people living in England are aware of the bans and what they think about them in focus groups. This will help us understand people’s perspectives in more depth than survey answers. We will include about 70-84 people in 14 different online focus groups – separated by age, whether people are parents or not and their social circumstances.
4. We will conduct online interviews with about 15-20 professionals to understand how the bans came about.
what are the possible benefits and risks of participating?
The benefits of taking part include receiving monetary tokens of appreciation and having the opportunity to discuss areas of interest. The risks of taking part include spending time on the research.
where is the study run from?
The study is run from the University of Cambridge, UK. We are working with partners from the Universities of Liverpool, Oxford, Stirling, Exeter and Waterloo as well as from the London School of Hygiene and Tropical Medicine.
When is the study starting and how long is it expected to run for?
The study will start in January 2026 and run until December 2028.
Who is funding the study?
National Institute of Health Research (NIHR) (UK)
Who Is the Main Study Contact?
Prof Jean Adams at the University of Cambridge: jma79@medschl.cam.ac.uk
Contact information
Public, Scientific, Principal investigator
MRC Epidemiology Unit
University of Cambridge School of Clinical Medicine
Level 3 Institute of Metabolic Science
Addenbrooke’s Treatment Centre
Cambridge Biomedical Campus
Cambridge
CB2 0SL
United Kingdom
 ORCID ID |
0000-0002-5733-7830 |
|---|---|
| jma79@medschl.cam.ac.uk |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Multi-component evaluation using natural experimental qualitative and modelling methods |
| Secondary study design | Multi-component evaluation |
| Scientific title | A multicomponent evaluation of new restrictions on marketing of less healthy foods in England |
| Study objectives | The research questions are: 1. Were there pre-post intervention changes in: a. prevalence of HFSS price promotions in UK supermarkets? b. prevalence of HFSS TV and online advertising (both product and brand)? c. exposure of UK adults to HFSS TV adverts? d. availability and price of HFSS products in UK supermarkets and chain restaurants? e. purchasing of HFSS products by English households? 2. What are the modelled impacts of any changes in purchasing on: a. prevalence of overweight, obesity and other relevant health outcomes in England? b. economic performance of relevant food, media & advertising industries & wider society in the UK? 3. What proportion of people living in England were aware of and supported the interventions? What were their experiences of the interventions? 4. Who were the key actors and what were the key actions involved in development, prioritisation, delay and implementation of the interventions? 5. Were any changes in outcomes identified in RQ1-3 due to the intervention? |
| Ethics approval(s) |
Not yet submitted |
| Health condition(s) or problem(s) studied | Unhealthy diets |
| Intervention | This is an evaluation of new restrictions on marketing of food and drinks high in fat, salt and sugar (HFSS), comprising bans on: • adverts for HFSS products on live broadcast TV and UK on-demand services (eg ITV hub, All4) from 0530-2100h from Jan 2026; • paid-for online adverts of HFSS products by UK operating businesses from Jan 2026; • multibuy (eg 3 for 2) and volume based (eg 50% extra free) price promotions on pre-packaged HFSS products in England from Oct 2025. Population (purchasing data) – participants sign up to be a member of the commercial household purchasing panel and comply with the panel’s requirements throughout. Population (marketing recall and intervention support) – participants are invited to take part in an online survey, provide consent, and then complete the survey at their convenience. Population (awareness, acceptability and experiences) – participants are invited to take part in an online focus group, provide consent, and then attend the focus group arranged to meet their availability. Health professionals (key actors and actions) – participants are invited to take part in an online 121 interview, provide consent, and then take part in the interview arranged to meet their availability. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
Prevalence of HFSS price promotions in UK supermarkets measured using commercially collected product data on products sold in 5 UK supermarkets from Sept 24 to Dec 26 and analysed using interrupted time series methods. |
| Key secondary outcome measure(s) |
1. Availability and price of HFSS products in UK supermarkets measured using commercially collected product data on products sold in 5 UK supermarkets from Sept 24 to Dec 26; analysed using interrupted time series methods. |
| Completion date | 31/12/2029 |
Eligibility
| Participant type(s) | Health professional, Population |
|---|---|
| Age group | Mixed |
| Lower age limit | 10 Years |
| Upper age limit | 100 Years |
| Sex | All |
| Target sample size at registration | 30000 |
| Key inclusion criteria | 1. Population (purchasing data)- adult household respondents who are members of commercial household purchasing panel living in England; age 18 years plus 2. Population (marketing recall and intervention support) - adults (age 18y+) and youth (age 10-17y) who took part in the International Food Policy Survey in 2024, 2025 or 2026 from the UK, Canada, Mexico and the USA. Recruitment is through Nielsen Consumer Insights Global Panel and their partners. 3. Population (awareness, acceptability and experiences) - adults (aged 18y+) and youth (aged 13-18y) living in England. Adult participants will be recruited from the general population through a GDPR-compliant market research agency operating an adult research panel. Participants aged 13-15y will be recruited via parents on the panel. 4. Health professionals (key actors and actions) - those with self-described professional knowledge and experience of UK food marketing regulations who are currently (or until recently were) working in academia, civil society, industry or government. |
| Key exclusion criteria | 1. Unable to provide consent. 2. Evidence that completed the survey too quickly or without enough attention (simple factual questions incorrect). |
| Date of first enrolment | 01/09/2024 |
| Date of final enrolment | 31/03/2027 |
Locations
Countries of recruitment
- United Kingdom
- England
- Scotland
- Canada
Study participating centres
Trinity Lane
Cambridge
CB2 1TN
England
Stirling
FK9 4LA
Scotland
Waterloo, ON
N2L 3G1
Canada
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | Much of the data we use in this work is proprietary and/or available from third parties under licence. We will not be able to share this data ourselves but will share contact details for interested parties to obtain the data themselves. Data from the International Food Policy Study is available upon request from Prof David Hammond: dhammond@uwaterloo.ca Qualitative data that we collect for this study will likely not be made available due to ethical and consent restrictions. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Protocol file | version 1.0 | 24/10/2025 | 13/11/2025 | No | No |
Additional files
Editorial Notes
13/11/2025: Uploaded protocol (not peer-reviewed) as an additional file.
23/10/2025: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).
