SEP and the Impact of Price on Food Selection in a Simulated Food Delivery App

Socioeconomic Position and the Effectiveness of Price Changes Based on Healthier and Less Healthy Food on Food Selection in a Simulated Out of Home Food Delivery App: a Randomised Controlled Trial

The goal of this randomised controlled trial is to compare taxation with subsidies to encourage healthier food choices in the out-of-home food sector. Participants will be asked to make hypothetical food choices in an online simulation study of a delivery app. Participants will be randomised into four different intervention groups:

1. Price reduction (10%) on healthier foods
2. Price increase (10%) to less healthy foods
3. A combination of price reduction to healthier foods and price increase to less healthy foods
4. Existing price structure (i.e. control group)

The investigators will further examine effectiveness of these fiscal policies on healthy eating by socioeconomic position to understand whether these policies are equitable.

Study Overview

• Status: Completed
• Conditions: Food Selection; Eating Behavior; Healthy Eating
• Intervention / Treatment: Behavioral: Price reduction on healthier foods; Behavioral: Price increase to less healthy foods; Behavioral: Combination of price reduction on healthier foods and price increase on less healthy foods; Behavioral: Control

• Study Type: Interventional
• Enrollment (Actual): 3464
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Merseyside
    • Liverpool, Merseyside, United Kingdom, L69 7ZA
      • University of Liverpool

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Currently reside in the United Kingdom
• Over the age of 18 years
• Order take-away food for delivery at least once a month
• Can complete the study on a laptop or desktop

Exclusion Criteria:

• Any major dietary restrictions (vegan, dairy/lactose-free, gluten-free) or allergies (dairy, eggs, nuts, soy, wheat) that would limit the number of dishes they could choose in the meal selection task

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Price reduction on healthier foods; Price reduction of 10% for healthier dishes (based on a score of less than 4 on the UK Nutrient Profile Model (NPM)); Existing price structure for less healthy dishes (based on a score of 4 or higher on the UK NPM)	Behavioral: Price reduction on healthier foods; Price reduction (10%) on healthier foods based on the UK NPM
Experimental: Price increase to less healthy foods; Price increase of 10% for less healthy dishes (based on a score of less than 4 on the UK NPM); Existing price structure for healthier dishes (based on a score of 4 or higher on the UK NPM)	Behavioral: Price increase to less healthy foods; Price increase (10%) on less healthy foods based on the UK NPM
Experimental: Combination of price reduction to healthier foods and price increase to less healthy foods; Price reduction of 10% for healthier dishes (based on a score of less than 4 on the UK NPM); Price increase of 10% for less healthy dishes (based on a score of 4 or higher on the UK NPM)	Behavioral: Combination of price reduction on healthier foods and price increase on less healthy foods; Combination of price reduction (10%) on healthier foods based on the UK NPM and price increase (10%) on less healthy foods based on the UK NPM
Placebo Comparator: Existing price structure (control); - No changes in prices	Behavioral: Control; Existing price structure

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Healthier vs less healthy main meals ordered based on the Nutrient Profiling Model and total energy (kcal)	Healthier vs less healthy main meals ordered	immediately after food choice
Total energy (kcal) ordered	The total energy content of the total hypothetical food order	immediately after food choice

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of selecting healthier vs less healthy meal items of the total food order based on the Nutrient Profiling Model and total energy (kcal)	Proportion of selecting healthier vs less healthy meal items of the total hypothetical food order	immediately after food choice
Total fat, saturated fat, salt and sugar ordered	Total fat, saturated fat, salt and sugar of total hypothetical food order	immediately after food choice

Collaborators and Investigators

• Sponsor: University of Liverpool
• Investigators: Principal Investigator: Eric Robinson, PhD, University of Liverpool

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2024
• Primary Completion (Actual): August 31, 2024
• Study Completion (Actual): August 31, 2024

Study Registration Dates

• First Submitted: June 11, 2024
• First Submitted That Met QC Criteria: June 14, 2024
• First Posted (Actual): June 21, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 24, 2025
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: Food Delivery Study

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Study data (anonymised) will be shared on the Open Science Framework (OSF)
• IPD Sharing Time Frame: On publication, indefinitely
• IPD Sharing Access Criteria: Open website
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No