Introduction - The problem
In the UK, diets are unhealthy. They are high in nutrients like sugar, salt, and saturated fat, and in ultra-processed foods (UPFs). Preparing food at home is often associated with a higher quality diet. However, preparing food at home requires skills, time, and energy.
We hypothesise that a recipe-box subscription may help households with children to prepare healthy meals at home more conveniently and affordably. Recipe-boxes may also lead to other benefits. For example, recipe-boxes may improve one’s food and cooking skills, capability to make food that one values, and quality of life. For households with children, recipe-boxes may also help children learn how to cook or appreciate a wider range of healthy dishes.
This intervention involves participants taking part in a recipe-box subscription for their household (2 to 5 recipes per week) for 6 weeks. Participants will receive a discount of 60% for the first week and 50% for the next 5 weeks (assuming one recipe box is ordered per week).
If participants choose, they may continue for another 4 weeks with a discount of 20%. Participants choose their order online from around 200 meals every week. Each box contains pre-portioned ingredients to prepare a meal, together with simple instructions.
Households with children of school age. We will start recruiting in Birmingham, but may expand to other areas if necessary.
Inclusion criteria:
Having at least one child attending primary or secondary school in the household.
Having access to cooking rings, an oven, and a fridge at home (needed to prepare Gousto’s recipes).
Exclusion criteria:
Have used recipe-boxes in the previous 3 months.
The main food provider (who will complete the surveys) who cannot read, write, and speak in English.
Not having access to internet and a digital device (smartphone, tablet, or laptop).
Any member of the household having recently participated (past 3 months), currently participating, or scheduled to participate, in another diet-related trial, cohort, or clinical study.
Primary research question
Does a recipe box subscription lead to a healthier dietary pattern, and if so for whom?
Theory of change
Research Questions
Primary objectives and outcome measures:
How acceptable are the recruitment strategies and enrolment procedures? (from sample size attained)
How acceptable is the recipe box subscription at the discounted rate? (from retention rate)
How acceptable is allocation to the waitlist control? (from retention rate)
What is the sample size needed for the main trial to detect an average treatment effect in the primary outcome in the main trial (dietary quality) with α of 0.05 and power of 0.90?
Qualitative outcomes include:
What are the perceived benefits of the recipe box subscription and barriers to participation? (from semi-structured interviews)
Are hypothesised mediators in the theory of change observed, and do they lead to longer-term benefits (e.g. independently planning and preparing meals)? (from semi-structured interviews)
Do recipe boxes affect participants’ food agency? (from semi-structured interviews)
Acceptability outcomes include:
How acceptable are the recruitment strategies and enrolment procedures? (from recruitment rate and semi-structured interviews)
How acceptable is the recipe box subscription at the discounted rate? (from retention rate, recipe box ordering rate, and from semi-structured interviews)
How acceptable is allocation to the waitlist control group? (from retention rate and from semi-structured interviews)
Feasibility outcomes include:
How feasible are the recruitment strategies and enrolment procedures? (from sample size attained, recruitment rate, and semi-structured interviews)
What is the level of adherence to allocation for the intervention group: ordering 2 to 5 recipes weekly, according to ordering data from Gousto?
What is the level of adherence to allocation for the waitlist control group: not obtaining recipe boxes from any sources? (from questionnaire and semi-structured interviews)
Is the implementation of trial procedures of high fidelity (e.g. execution of the social media campaigns; digital and in-person recruitment from schools, employers, and community organisations; recruitment through Gousto’s existing customers; notifications and follow-up by study team)
Research approach
We will conduct a parallel-group and unblinded pilot and feasibility randomised controlled trial with a waitlist for the control group. Households will be randomised in a 1:1 allocation.
Participants will be recruited via social media platforms (Facebook, Instagram, TikTok, and NextDoor), and via schools, employers, and community organisations. Gousto will also send invitations for existing customers to refer friends to take part in the study. Following links or QR codes, participants will be directed to an eligibility form. If eligible, they will be asked to submit their contact details to be sent the participant information sheet and consent form. If participants decide to participate, they will complete the consent form. Participants will then complete baseline questionnaires and be randomised. We aim to randomise n = 150 participants (n = 75 per group).
Key outcomes for the pilot trial will be the acceptability of the recruitment strategies, enrolment procedures, recipe-box subscription, and waitlist control group for participants.
We will also examine the feasibility of the recruitment strategies and enrolment procedures, and to what extent participants adhere to their group allocation.
Qualitatively, we will examine the perceived benefits of the recipe-box subscription, and barriers to participation, and whether mediators in our theory of change are observed. We will also explore whether and how the recipe-box subscription affected participants’ food agency—that is, their capability to prepare food that they value.
Research Partners
This trial is part of the SALIENT Food Trials, a collaboration between eight universities (Oxford, Cambridge, Warwick, Birmingham, Hertfordshire, Liverpool, London School of Hygiene and Tropical Medicine, and Queen Mary University of London) and two research institutes (Nesta and the Behavioural Insights Team). A commercial partner will provide and deliver recipe boxes to participants.
Planned publications in peer reviewed journals.
Separate publications for 1) the protocol, 2) quantitative and qualitative outcomes, acceptability, and feasibility, and 3) qualitative analyses of the impacts of recipe-boxes on participants’ food agency.
Prof Martin White—Chief Investigator | MRC Epidemiology Unit, University of Cambridge
Noah C. A. Cooke—PhD Student, Study Lead | MRC Epidemiology Unit, University of Cambridge
Prof Jean Adams—Investigator | MRC Epidemiology Unit, University of Cambridge
Prof. Jaideep Prabhu—Investigator | Judge Business School, University of Cambridge
Stephen Sharp—Senior Statistician | MRC Epidemiology Unit, University of Cambridge
Dr Sarah Shaw—Research Associate | MRC Epidemiology Unit, University of Cambridge
Dr Catrin Jones—Research Associate | MRC Epidemiology Unit, University of Cambridge
Dr Tom Ball—Research Associate | Department of Zoology, University of Cambridge
Dr Claire Thompson—Senior Research Fellow | University of Hertfordshire
Prof Emma Frew—Professor, Institute of Applied Health Research | University of Birmingham
Dr Lin Fu—Research Fellow | Institute of Applied Health Research | University of Birmingham
Dr. Rachel Loopstra—Senior Lecturer | University of Liverpool
We are funded by the Economic and Social Research Council (ESRC)’s SALIENT Food Trials Grant [ES/Y00311X/1].
The study will be sponsored by the University of Cambridge (G122382).
This study has been approved [25.397] by the Humanities and Social Sciences Research Ethics Committee at the University of Cambridge
For information on our data access and sharing policy, see our data sharing pages.
