Impact of Environmental Nudges on Dietary Quality

Purpose: The overall purpose of this study is to evaluate the impact of a suite of environmentally focused nudges on the nutritional quality of consumers' food selections.

Participants: ~2,000 US adults ages 18-25, at least 25% currently enrolled full-time in college, recruited from CloudResearch Prime Panels.

Procedures: Participants will be randomly assigned to view food products with or without environmental nudges (eco-labels, peer comparison message, and swaps). They will be asked to select items that they most wish to purchase and will then be asked a series of questions about the products and nudges. Questions will also include standard socio-demographic variables.

Study Overview

• Status: Completed
• Conditions: Healthy Diet
• Intervention / Treatment: Behavioral: Environmental nudges

Detailed Description

Participants will be recruited from CloudResearch Prime Panels (an online panel research company). Study participants include 2,000 young adults between 18 and 25 years old with at least 25% currently enrolled in college, recruited to match census distribution of race/ethnicity and gender. Participants will electronically acknowledge their consent to participate in the study.

On the study platform (Qualtrics), participants will be randomly assigned to 1 of 2 arms with equal probability. Participants will complete a shopping task via an online 9-minute survey. They will view products displayed as if they were offered from a grocery store. Products will be frozen meals, such as burritos and pizza, snack items such as dried fruit and chips, and protein items, such as ground beef and chicken breasts. They will then be instructed to select 1 item they most wish to purchase from each category.

Participants in the experimental arm will shop and receive environmental nudges in the form of labels, feedback, peer comparisons, and suggested product swaps. In the control arm, participants will conduct online shopping tasks without any environmental nudges. After selecting products, participants will answer questions about the products and labels, as well as standard socio-demographic questions.

• Study Type: Interventional
• Enrollment (Actual): 2132
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • UNC Carolina Population Center

Participation Criteria

Eligibility Criteria

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

Description

Inclusion criteria:

• 18 to 25 years old
• Currently resides in the United States

Exclusion criteria:

• Completion of the survey in <1/3 of the median completion time

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; Participants will conduct online shopping tasks without any environmental nudges. This includes no labels, peer comparison messages, or suggested product swaps.
Experimental: Environmental; Participants in the experimental arm will shop and receive environmental nudges in the form of labels, peer comparisons messages, and suggested product swaps.	Behavioral: Environmental nudges; Participants will view protein, frozen meal, and snack products with eco-labels applied. For each category, they will then be instructed to select 1 item from that category they wish most to purchase. Categories will be shown in random order. If a participant selects a product with a red eco-label, they will be shown a peer comparison message and will be given an opportunity to switch to a product with a yellow or green eco-label.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nutri-Score Scores	Healthfulness of product selections (operationalized as products' Nutri-Score scores). Products' Nutri-Score scores are calculated using the updated 2022 algorithm released by the Scientific Committee of the Nutri-Score (ScC). Scores range from -15 (Nutri-Score of "A") to 40 (Nutri-Score of "E"), with lower scores indicating a more healthful product selection.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Carbon Footprint	Carbon footprint of product selections [operationalized as products' greenhouse gas emissions (GHGE) per 100g].	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Acceptability of Eco-Label Intervention	Acceptability of eco-labels on products, measured by an item adapted from Vargas-Meza et al., 2019. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher acceptability of eco-labels.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Acceptability of Swaps Intervention	Acceptability of environmental swaps, measured by an item adapted from Vargas-Meza et al., 2019. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher acceptability of swaps.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Acceptability of Peer Comparison Message Intervention	Acceptability of peer comparison messages, measured by an item adapted from Vargas-Meza et al., 2019. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher acceptability of peer comparison messages.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Health Elaboration	How much the participant reports thinking about the healthfulness of products when making selections. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher amount of thinking about the healthfulness of products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Taste Elaboration	How much the participant reports thinking about the taste of products when making selections. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher amount of thinking about the taste of products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Cost Elaboration	How much the participant reports thinking about the cost of products when making selections. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher amount of thinking about the cost of products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Environmental Sustainability Elaboration	How much the participant reports thinking about the environmental sustainability of products when making selections. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "A great deal" (coded as 5), with higher scores representing a higher amount of thinking about the environmental sustainability of products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Perceived Healthfulness of Sustainable Products	Participants' perceptions about the healthfulness of sustainable products. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "Extremely" (coded as 5), with higher scores representing a higher perceived healthfulness of sustainable products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Perceived Healthfulness of Unsustainable Products	Participants' perceptions about the healthfulness of unsustainable products. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "Extremely" (coded as 5), with higher scores representing a higher perceived healthfulness of unsustainable products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Perceived Sustainability of Sustainable Products	Participants' perceptions about the sustainability of sustainable products. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "Extremely" (coded as 5), with higher scores representing a higher perceived sustainability of sustainable products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Perceived Sustainability of Unsustainable Products	Participants' perceptions about the sustainability of unsustainable products. Likert responses are on a 1 to 5 scale, from "Not at all" (coded as 1) to "Extremely" (coded as 5), with higher scores representing a higher perceived sustainability of unsustainable products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Purchase Intentions of Sustainable Products	Participants' intentions to purchase a sustainable product in the next month. Likert responses are on a 1 to 5 scale, from "Not at all likely" (coded as 1) to "Extremely likely" (coded as 5), with higher scores representing a higher intention to purchase.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Purchase Intentions of Unsustainable Products	Participants' intentions to purchase an unsustainable product in the next month. Likert responses are on a 1 to 5 scale, from "Not at all likely" (coded as 1) to "Extremely likely" (coded as 5), with higher scores representing a higher intention to purchase.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Injunctive Norms	Participants' perceived approval from people important in their life for purchasing environmentally sustainable products. Likert responses are on a 1 to 5 scale, from "Strongly disagree" (coded as 1) to "Strongly agree" (coded as 5), with higher scores representing higher perceived approval about purchasing environmentally sustainable products.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit
Descriptive Norms	Participants' belief that most shoppers purchase environmentally sustainable foods when shopping for groceries. Likert responses are on a 1 to 5 scale, from "Strongly disagree" (coded as 1) to "Strongly agree" (coded as 5), with higher scores representing higher belief that most shoppers purchase environmentally sustainable foods.	Immediately after exposure to intervention and product selection task, assessed during 1-time online study visit

Collaborators and Investigators

• Sponsor: University of North Carolina, Chapel Hill
• Collaborators: Wellcome Trust
• Investigators: Principal Investigator: Lindsey Smith Taillie, PhD, University of North Carolina, Chapel Hill; Principal Investigator: Anna H Grummon, PhD, Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): November 28, 2023
• Primary Completion (Actual): December 4, 2023
• Study Completion (Actual): December 4, 2023

Study Registration Dates

• First Submitted: October 24, 2023
• First Submitted That Met QC Criteria: November 2, 2023
• First Posted (Actual): November 7, 2023

Study Record Updates

• Last Update Posted (Estimated): January 3, 2024
• Last Update Submitted That Met QC Criteria: January 2, 2024
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 23-1785

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: A deidentified dataset and the corresponding survey codebook will be published to a data repository. The study protocol, statistical analysis plan, and informed consent form will be published alongside as supplementary material.
• IPD Sharing Time Frame: The deidentified dataset and corresponding survey codebook will be available upon publication of study results and will be available indefinitely.
• IPD Sharing Access Criteria: Anyone who wishes to access the data.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No