How to frame swaps within an online supermarket platform to maximise acceptance rates: comparing health, social norms and cost framed messages

Message framing for uptake of within-category healthy food swaps: an experimental online supermarket study across socio-economic groups

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN67116897

Enrollment

900

Registered

2015-09-30

Start date

2015-10-01

Completion date

Unknown

Last updated

2021-05-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Online supermarket shopping Nutritional, Metabolic, Endocrine

Interventions

The study will follow a between-subjects experimental design with three arms, assessing the impact of swap framing on swap acceptance. The effects will be compared with a simple health framing control

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Participants will be recruited via a research agency and will cover a spread of socio-economic status ABC1 (53%), C2DE (47%), gender (50:50) and age (18 to 80). Screening questions will be used to ensure all participants are responsible for “about half” or “all or most” of the food/grocery shopping (UK national surveys indicate this to be the case for 73% of the population (Food Standards Agency, 2011)).

Exclusion criteria

Exclusion criteria: Participants who are not responsible for “about half” or “all or most” of the food/grocery shopping

Design outcomes

Primary

Measure	Time frame
Proportion accepted swaps: number of swaps accepted, number of swaps offered	—

Secondary

Measure	Time frame
1. Energy density (kJ per 100g) of the basket of goods purchased and the basket of original goods chosen, i.e. had swaps not been offered 2. Nutrient content of basket of goods purchased and of basket of original goods chosen including saturated fat, total sugar and salt 3. Acceptability of intervention – measured after completion of shopping. 4. Age 5. Gender 6. Self-reported weight 7. Self–reported height 8. SES: individual level – both highest educational qualification (UK census levels) and household income	—

Measure

Time frame

1. Energy density (kJ per 100g) of the basket of goods purchased and the basket of original goods chosen, i.e. had swaps not been offered 2. Nutrient content of basket of goods purchased and of basket of original goods chosen including saturated fat, total sugar and salt 3. Acceptability of intervention – measured after completion of shopping. 4. Age 5. Gender 6. Self-reported weight 7. Self–reported height 8. SES: individual level – both highest educational qualification (UK census levels) and household income

—

Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026