Climate Labels for Restaurant Menus Pilot

March 19, 2025 updated by: Jennifer Falbe, University of California, Davis

Comparing the Impact of Climate Labels for Restaurant Menus: a Pilot Study

The aim of this study is to compare responses to 6 different types of labels for restaurant menus: 1) a QR code on all items (control); 2) High Climate Impact label; 3) High Climate Impact Warning label; 4) Climate Grade label; 5) Climate Grade label also displaying full range of possible grades; 6) Estimated Environmental Cost label. Participants will be randomized to 1 of these 6 labeling arms. Each participant will view a menu based on a real-world restaurant with one of the 6 labels shown on applicable menu items, select the menu item they would like, and then respond to survey questions about each label.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This is an online randomized controlled trial in which researchers will use a survey company to recruit participants to an online survey. In the study, participants will be randomized to 1 of 6 labeling arms: 1) a QR code on all items (control); 2) High Climate Impact label; 3) High Climate Impact Warning label; 4) Climate Grade label; 5) Climate Grade label also displaying full range of possible grades; 6) Estimated Environmental Cost label. Labels will only appear alongside main menu items and will be assigned using thresholds for greenhouse gas emissions set a priori in kilograms of CO2 equivalent per kilogram of food. Each participant will view a menu based on a real-world restaurant with one of the 6 labels shown on applicable menu items, select the menu item they would like, then respond to survey questions about each label.

For dichotomous outcomes, the investigators will directly estimate the probability ratio using Poisson regression with a robust error variance, regressing the outcome on indicators for experimental condition. For continuous outcomes, the investigators will use linear regression models, regressing the outcome on indicators for experimental condition. A critical alpha 0.05 will be used, and statistical tests will be two-tailed. Investigators will compare all experimental label conditions to the control label, then compare each experimental label to each other using pairwise comparisons.

Study Type

Interventional

Enrollment (Actual)

16181

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

    • California
      • Davis, California, United States, 95616
        • University of California, Davis

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:

  • 18 years and older
  • English-speaking
  • U.S. residents
  • Have eaten restaurant food at least once in the last month
  • Participants will reflect the U.S. Census Bureau's American Community Survey estimates for sex, race/ethnicity, educational attainment, and age

Exclusion Criteria:

  • Non-US resident
  • Younger than 18 years old
  • Failing the attention check question
  • Completing the survey in less than 33% of the median completion time

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Control (QR) labels
Labels placed beneath all menu items will contain QR codes with the text, "scan here", without any mention of sustainability
Participants will view a sample of items from a restaurant menu, displayed with labels
Experimental: High Climate Impact labels
Labels will be placed beneath menu items with a high climate impact using a predetermined threshold of estimated greenhouse gas emissions set at >=9.2 kgCO2e. Labels will contain white text, "High Climate Impact", on a red background with a globe icon
Participants will view a sample of items from a restaurant menu, displayed with labels
Experimental: High Climate Impact Warning labels
Labels will be placed beneath menu items with a high climate impact using a predetermined threshold of estimated greenhouse gas emissions set at >=9.2 kgCO2e. Labels will contain white text, "Warning: High Climate Impact", on a red background with a globe icon
Participants will view a sample of items from a restaurant menu, displayed with labels
Experimental: Climate Grade labels
Labels will be placed beneath all menu items, using predetermined estimated greenhouse gas emission thresholds to assign one of five icon-plus-text labels which indicate a specific climate impact grade (A, B, C, D, and F). Thresholds are set in kgCO2e as follows: [A] <1.7, [B] >=1.7 & <2.6, [C] >=2.6 & <9.2, [D] >=9.2 & <28, [F] >=28. Labels shown will contain white text, "Climate Grade", on a black background with a globe icon. The labels will include a white letter in a colored box on the left side, A (dark green), B (light green), C (yellow), D (orange), or F (red)
Participants will view a sample of items from a restaurant menu, displayed with labels
Experimental: Climate Grade label also displaying full range of possible grades
Labels will be placed beneath all menu items, using predetermined estimated greenhouse gas emission thresholds to assign one of five icon-plus-text labels which indicate a specific climate impact grade (A, B, C, D, and F). Thresholds are set in kgCO2e as follows: [A] <1.7, [B] >=1.7 & <2.6, [C] >=2.6 & <9.2, [D] >=9.2 & <28, [F] >=28. Labels shown will contain white text, "Climate Grade", on a black background with a globe icon. The labels will include a white letter in a colored box on the left side, A (dark green), B (light green), C (yellow), D (orange), or F (red). This label will also include a small scale of each white letter and colored box option beneath the main white letter and colored box
Participants will view a sample of items from a restaurant menu, displayed with labels
Experimental: Estimated Environmental Cost labels
Labels will be placed beneath all menu items, displaying the estimated dollar value associated with greenhouse gas emissions. Labels shown will contain white text, "Environmental Cost," with a dollar value (i.e., +$10.90) on a black background with a globe icon
Participants will view a sample of items from a restaurant menu, displayed with labels

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
High climate impact menu item selected - dichotomous variable
Time Frame: Up to approx. 1 minutes
Measured as a dichotomous variable (yes/no) indicating whether participants' hypothetical meal orders include a high climate impact menu item.
Up to approx. 1 minutes
Total greenhouse gas emissions - continuous variable
Time Frame: Up to approx. 1 minute
Cumulative total kilograms of carbon equivalent (kgCO2e) per kilogram of food for all meal items.
Up to approx. 1 minute

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Modified Nutrient Profile Index (NPI) score - continuous variable
Time Frame: Up to approx. 1 minute

NPI scores are based on the UK Ofcom Nutrient Profiling Model, which is used to score individual foods in the U.K. to determine which ones can be marketed to children. The NPI generates a 0 to100-point score for foods and beverages where scores >=64 are considered healthy. NPI scores are based on points awarded from nutrients to encourage (e.g., percent fruits and vegetables, grams of fiber and protein) and nutrients of concern (e.g., sodium, sugar) per 100 grams. For this study, we will generate a modified NPI score to evaluate the healthfulness of full meals comprised of multiple food items. This measure will be determined by calculating the weighted mean NPI score of all food items selected per meal, with each item's NPI score weighted by its proportionate contribution of mass in grams to the total mass of the meal.

Reference: Rayner, M., Scarborough, P., Boxer, A., & Stockley, L. (2005). Nutrient profiles: development of final model. London: Food Standards Agency.

Up to approx. 1 minute
Total energy (kcal) selected - continuous variable
Time Frame: Up to approx. 1 minute
The total number of calories in participants' hypothetical meal orders, calculated as the sum of calories across all menu items selected. Higher values indicate more calories selected.
Up to approx. 1 minute
Total saturated fat (g) selected - continuous variable
Time Frame: Up to approx. 1 minute
The total grams of saturated fat in participants' hypothetical meal orders, calculated as the sum of grams of saturated fat across all menu items selected. Higher values indicate more saturated fat selected.
Up to approx. 1 minute
Total sodium (mg) selected - continuous variable
Time Frame: Up to approx. 1 minute
The total milligrams of sodium in participants' hypothetical meal orders, calculated as the sum of milligrams of sodium across all menu items selected. Higher values indicate more sodium selected.
Up to approx. 1 minute

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Effectiveness - categorical variable
Time Frame: Up to approx. 1 minute

A single item adapted from the UNC-PME scale to measure how much the climate labels discouraged wanting to purchase an item that has a high climate impact with the question: "How much does this label discourage you from wanting to purchase an item that has a high climate impact?" With response options: "Not at all," "A little bit," "Somewhat," "Quite a bit," and "A great deal."

Reference: Baig, S. A., Noar, S. M., Gottfredson, N. C., Boynton, M. H., Ribisl, K. M., & Brewer, N. T. (2019). UNC perceived message effectiveness: validation of a brief scale. Annals of Behavioral Medicine, 53(8), 732-742.

Up to approx. 1 minute
Noticeability - dichotomous variable
Time Frame: Up to approx. 1 minute

Measured as a dichotomous variable (yes/no) indicating whether participants noticed and can correctly recall the climate, environmental, or control label with the question: "Did you notice any labels (other than calories) next to or below the menu items?." With response options: "Yes, a climate label" (or "Yes, an environmental label" in the environmental cost condition), "Yes, a heart healthy label," "Yes, a vegan label," "Yes, an organic label," "Yes, a local label," "Yes, a QR code label," "No, I did not see a label," "Not sure."

There is no formal name for this measure. It was developed for this study.

Up to approx. 1 minute
Support - categorical variable
Time Frame: Up to approx. 1 minute

Measured with a single item: "Imagine the city you live in is considering a policy that would add the label(s) shown below to relevant menu items in chain restaurants. Would you…?" With an image of the assigned label condition the participant was randomized to and the response options: "Strongly oppose this policy," "Somewhat oppose this policy," "No opinion," "Somewhat support this policy," "Strongly support this policy."

There is no formal name for this measure. It was developed for this study.

Up to approx. 1 minute

Collaborators and Investigators

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

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)

December 23, 2024

Primary Completion (Actual)

February 13, 2025

Study Completion (Actual)

February 13, 2025

Study Registration Dates

First Submitted

October 18, 2024

First Submitted That Met QC Criteria

October 18, 2024

First Posted (Actual)

October 21, 2024

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

March 19, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • 1641776-8C

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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