Plant-Based Defaults

July 14, 2025 updated by: Chad Stecher@asu.edu, Arizona State University

Using Defaults to Reduce Harmful Environmental Impacts

In this study, participants at six different academic events were randomly assigned to one of two conditions: (1) a default meat group, where the default choice was a meal with meat and participants had the option of opting out and choosing a plant-based meal; and (2) a default veg group, where the default choice was a plant-based meal with the option of opting out and choosing a meal with meat. Based on the success of prior studies that implemented plant-based defaults through preselection, we hypothesized that more participants would choose the plant-based meal when that option was set as the default, and we hypothesized that the default intervention would be equally effective across academic institutions. We also hypothesized that the default intervention would be equally effective across demographic groups, which would help to further demonstrate the generalizability of our plant-based default intervention.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

365

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85004
        • Arizona State University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Academic event attendee

Exclusion Criteria:

  • None

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Default Veg
Received a plant-based meal as the default option on the event RSVP form that required participants to pre-select their meal choice
Behavioral: Default Veg
Received a plant-based meal as the default option on the event RSVP form that required participants to pre-select their meal choice
Active Comparator: Default Meat
Received a meal with meat as the default option on the event RSVP form that required participants to pre-select their meal choice
Behavioral: Default Meat
Received a meal with meat as the default option on the event RSVP form that required participants to pre-select their meal choice

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of participants selecting the plant-based meal
Time Frame: Immediately during the completion of the event RSVP form
The percent (%) of participants selecting the plant-based meal option instead of the meal with meat option on the event RSVP from
Immediately during the completion of the event RSVP form

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Arizona State University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2022

Primary Completion (Actual)

August 12, 2022

Study Completion (Actual)

February 22, 2024

Study Registration Dates

First Submitted

July 29, 2024

First Submitted That Met QC Criteria

August 13, 2024

First Posted (Actual)

August 15, 2024

Study Record Updates

Last Update Posted (Actual)

July 15, 2025

Last Update Submitted That Met QC Criteria

July 14, 2025

Last Verified

July 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • STUDY00016889

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified study will be share through the ASU Research Data Repository

IPD Sharing Time Frame

Shortly after our manuscript is accepted for publication

IPD Sharing Access Criteria

https://doi.org/10.48349/ASU/C1CWX9

IPD Sharing Supporting Information Type

  • ANALYTIC_CODE
  • CSR

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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