Out-of-home Consumer Food Purchase Behaviour in the Presence and Absence of Value Pricing and Price Promotions

It is important to understand the role that price-based incentives in the out-of-home food sector play in food purchasing, and whether they lead to positive savings for the consumer (as they would likely anticipate when making purchases), or whether these incentives lead to increased spending and increased purchasing of unhealthy products. Additionally, it is important to consider whether the impacts of price-based incentives differ according to a range of demographic characteristics. For example, some evidence suggests that effects of removing a price-based incentive are greater in individuals with a higher BMI. Evidence also suggests there may also be differences in impact according to socioeconomic position (SEP) as individuals in lower SEP groups reportedly use price-based incentives more frequently. If lower SEP individuals are more affected by price-based incentives (i.e. they prompt ordering in excess and greater spend), then the banning of such strategies could help to reduce health inequalities, by nudging lower SEP consumers toward healthier dietary choices in the OOH food sector.

To date, it is unclear what effect policies which remove specific types of price-based incentives would be likely to have on consumer behaviour. In particular, individual product price reductions (e.g. £ off this product), bulk buy price reductions (e.g., Save £ when bought together) and volume value pricing (e.g., the price increase from a small to large portion size not being directly proportional to volume increase).

Therefore our primary objectives are:

• To observe the effect of removing price-based incentives (individual product price reductions, bulk buy price reductions, volume value pricing) in the OOH food sector on:

• Energy purchased per household
• Money spent per household

Secondary Objectives:

• To explore whether any effects of removing price-based incentives differ based on participant characteristics (BMI, SEP, food choice motives)

Study Overview

• Status: Completed
• Conditions: Food Selection; Eating Behavior; Healthy Eating
• Intervention / Treatment: Behavioral: Control; Behavioral: Product price promotions removed; Behavioral: Bulk buy reductions removed; Behavioral: Volume value pricing removed; Behavioral: No price-based incentives

Detailed Description

See attached study protocol for detailed information

• Study Type: Interventional
• Enrollment (Actual): 2051
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Liverpool, 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
• Fluent English speaker Frequently use food delivery apps or websites (at least once a month, on average)
• Frequently eat takeaway pizza (i.e. once every 2-3 months)
• Can complete the study on a laptop or desktop

Exclusion Criteria:

• Partaking in a fast or other restrictive eating for religious reasons at time of participation

• Dietary restrictions/intolerances including:

  • Gluten-free
  • Dairy-free
  • Sugar-free

Study Plan

How is the study designed?

Design Details

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

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Control; Food menu typical for the out-of-home outlet with; Product price promotions (25% off orders over £10); Bulk buy reductions (bundle options for reduced prices); Volume value pricing (increase in size for a disproportionately small increase in price)	Behavioral: Control; Food menu will be provided as is typical for the out of home outlet
Experimental: Product price reductions removed; Food menu without product price promotions	Behavioral: Product price promotions removed; Food menus with no price reductions to products
Experimental: Bulk buy price reductions removed; Food menu without price decrease for bulk-buy items (i.e. bundles available but not at a decreased price)	Behavioral: Bulk buy reductions removed; Food menus with bundles provided but not at reduced prices
Experimental: Volume value pricing removed; For products on the food menu with size increases, increases in price will be made proportionate (as opposed to value)	Behavioral: Volume value pricing removed; Food menus with proportionate pricing for multi-size products
Experimental: No price-based incentive; Food menus will be provided with no price-based incentives	Behavioral: No price-based incentives; Food menus with no price-based incentives offered

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Energy (kcal) ordered	The total energy content of the hypothetical food order	immediately after food choice
Monetary value of order	The total monetary value of the hypothetical food order	immediately after food choice
Likelihood of using a bulk-buy promotion	The likelihood of participants selecting a bulk-buy option or 'bundle'	immediately after food choice
Likelihood of selecting a larger or smaller size	The likelihood of participants selecting a larger or smaller size for food items with multi-size options	immediately after food choice

Collaborators and Investigators

• Sponsor: University of Liverpool
• Collaborators: University of Bristol; Liverpool John Moores University; Economic and Social Research Council, United Kingdom

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2024
• Primary Completion (Actual): July 26, 2024
• Study Completion (Actual): October 28, 2024

Study Registration Dates

• First Submitted: May 8, 2024
• First Submitted That Met QC Criteria: May 8, 2024
• First Posted (Actual): May 14, 2024

Study Record Updates

• Last Update Posted (Estimated): November 1, 2024
• Last Update Submitted That Met QC Criteria: October 29, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: Price-based incentive 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