Climate Impact Label Design and Fast-Food Meal Selection

Testing Climate Impact Menu Labels Influence on Nutrition Quality of Fast-Food Selections: A Pilot Study

The primary objective of this study is to test the relative effects of climate-impact menu label designs on the healthfulness of consumers' fast-food meal choices. Participants will complete a hypothetical online meal ordering task using a survey which emulates the online menu of a burger restaurant chain. Participants will be randomized for exposure to menus featuring one of five labeling conditions. Secondary objectives include examining total greenhouse gas emissions per meal order and, through a post-order survey, perception of labels between the conditions.

Study Overview

• Status: Completed
• Conditions: Food Selection
• Intervention / Treatment: Behavioral: Control (QR) Labels; Behavioral: Warning High Climate Impact Labels; Behavioral: Traffic Light Labels; Behavioral: Climate Grade Labels; Behavioral: Numeric Carbon Footprint Labels

Detailed Description

This online randomized trial will test the relative effects of climate impact menu label designs on the healthfulness of consumers' fast-food meal choices and perceptions of menu items. The survey research firm CloudResearch will recruit a sample of 6,250 adults aged 18 years and older who speak English and reside in the United States.

Participants will complete a between-subjects online experiment in which the participants will be randomized to view a fast-food online ordering menu with one of five labeling schemes applied: (1) a QR code on all items (control); (2) a high climate impact warning label on high impact items; (3) traffic light labels on all items by level of impact; (4) climate grade labels on all items by level of impact; and (5) numeric carbon footprint labels on all items. All fast-food menus will include main items, sides, desserts, and drinks. Labels will only appear alongside main menu items and will be assigned using thresholds for greenhouse gas emissions set a priori in kilograms of carbon dioxide (CO2) equivalent per kilogram of food. Participants will be instructed to select up to 4 menu items for a hypothetical meal order. After completing the meal ordering task, participants will be prompted to answer questions about the perception of the labeling condition which the participants were randomized to view, perception of the relative effectiveness of all labels in this experiment, and personal values, dietary patterns, and other demographic information.

The primary outcome will be the healthfulness of meal orders selected from the online menu, indicated by a modified Nutrient Profile Index meal score for all food items ordered. Secondary outcomes will be total greenhouse gas emissions per meal ordered, total calories ordered, whether a sugar-sweetened beverage was ordered, and perceived message effectiveness of the climate-impact labels.

• Study Type: Interventional
• Enrollment (Actual): 6622
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21205
      • Johns Hopkins Bloomberg School of Public Health

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• 18 years of age or older
• Member of the CloudResearch panel
• Residing in the United States

Exclusion Criteria:

• Under 18 years of age
• Not residing in the United States
• Completed the survey implausibly quick based on the distribution of the time to complete the survey among all participants
• Failed the built-in Qualtrics survey fraud detection measures

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

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control (QR) Labels; A black label featuring a QR code and white text that reads "SCAN HERE" will be placed beneath all main menu items. Explanatory text describing the label's meaning will be displayed at the top of the menu.	Behavioral: Control (QR) Labels; Participants will view a fast-food restaurant menu including main, side, dessert, and drink items. Each menu item will be displayed with an image of the item, name, price, and total calories. For main items only, Control (QR) labels will be displayed beneath each item. Participants will be instructed to select up to 4 menu items for a hypothetical meal order.
Experimental: Warning High Climate Impact Labels; A red icon-plus-text label that reads "WARNING: HIGH CLIMATE IMPACT" in white text will be placed beneath main menu items with a high climate impact using a predetermined threshold of estimated greenhouse gas emissions set at >=9.2 kgCO2e. Labels will include a white globe icon directly preceding the label text. Explanatory text describing the label's meaning will be displayed at the top of the menu.	Behavioral: Warning High Climate Impact Labels; Participants will view a fast-food restaurant menu including main, side, dessert, and drink items. Each menu item will be displayed with an image of the item, name, price, and total calories. For main items only, Warning High Climate Impact labels will be displayed beneath select items. Participants will be instructed to select up to 4 menu items for a hypothetical meal order.
Experimental: Traffic Light Labels; Traffic Light labels will be placed beneath all main menu items. Using predetermined estimated greenhouse gas emission thresholds, each item will be assigned one of three icon-plus-text labels within this scheme: low-, medium-, or high-impact label, set in kgCO2e at <2.6, >=2.6 & <9.2, and >=9.2, respectively. Each will read, "HIGH CLIMATE IMPACT" within a red label, "MED. CLIMATE IMPACT" in a yellow label, and "LOW CLIMATE IMPACT" in a green label. Text for all labels written in white, and a white globe icon will precede the text. Explanatory text describing the meaning of the labels will be displayed at the top of the menu.	Behavioral: Traffic Light Labels; Participants will view a fast-food restaurant menu including main, side, dessert, and drink items. Each menu item will be displayed with an image of the item, name, price, and total calories. For main items only, Traffic Light labels will be displayed beneath each item. Participants will be instructed to select up to 4 menu items for a hypothetical meal order.
Experimental: Climate Grade Labels; Climate Grade labels will be placed beneath all main 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. All labels are solid black with a white globe icon followed by white text which reads "CLIMATE GRADE". On the left side of each label, a grade is displayed, capitalized and in a white font within a solid-colored box. The color of the box corresponds with each letter grade: A = dark green, B = light green, C = yellow, D = orange, F = red. Beneath the letter grade, a gradient of all possible grades is displayed horizontally in smaller font, each grade atop a small solid box in the respective grade color. Explanatory text describing the meaning of the labels will be displayed at the top of the menu.	Behavioral: Climate Grade Labels; Participants will view a fast-food restaurant menu including main, side, dessert, and drink items. Each menu item will be displayed with an image of the item, name, price, and total calories. For main items only, Climate Grade labels will be displayed beneath each item. Participants will be instructed to select up to 4 menu items for a hypothetical meal order.
Experimental: Numeric Carbon Footprint Labels; Numeric Carbon Footprint labels will be placed beneath all main menu items and display the estimated greenhouse gas emissions in kilograms of carbon dioxide equivalents (kgCO2e) for each item. All labels have a solid black background and an icon-plus-text design. A white globe icon is followed by text stating the value of the items estimated emissions and the unit "kgCO2e". Explanatory text describing the meaning of the labels will be displayed at the top of the menu.	Behavioral: Numeric Carbon Footprint Labels; Participants will view a fast-food restaurant menu including main, side, dessert, and drink items. Each menu item will be displayed with an image of the item, name, price, and total calories. For main items only, Numeric Carbon Footprint labels will be displayed beneath each item. Participants will be instructed to select up to 4 menu items for a hypothetical meal order.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Modified Nutrient Profile Index Score	The primary outcome measure will be the healthfulness of the fast-food meal selections, measured with a modified Nutrient Profile Index (NPI) score. NPI scores are based on the United Kingdom (UK) Ofcom Nutrient Profiling Model, which is used to score individual foods in the UK to determine which ones can be marketed to children. The NPI is a 0 to 100-point score for foods; scores >=64 are considered healthy. NPI awards points from nutrients to encourage (e.g., fiber, protein) and nutrients of concern (e.g., sodium, sugar) per 100 grams. The investigators 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.	approximately 1 minute

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Greenhouse Gas Emissions as Assessed by Cumulative Total Kilograms of Carbon Equivalent (kgCO2e) Per Kilogram	Cumulative total kilograms of carbon equivalent (kgCO2e) per kilogram of food for all meal items.	approximately 1 minute
Perceived Message Effectiveness (PME) as Assessed by the University of North Carolina (UNC) PME Scale	The 3-item University of North Carolina (UNC)-PME scale measures how much the label placed beneath high climate impact menu items, discouraged consumption or evoked concern or unpleasantness about consumption of high climate impact foods. Responses to all questions will be measured on a 5-point unipolar Likert scale from 1=Not at all to 5= A great deal. Preceding the questions, participants will view the assigned label demonstrating high climate impact and the following prompt: "Considering this label, how much do you agree or disagree with the following statements." The exact text for each question is: "This label discourages me from wanting to eat foods with a high climate impact." " This label makes eating foods with a high climate impact seem unpleasant." " This label makes me concerned about eating foods with a high climate impact." The mean likert scale choice is reported. The scale choice range is between 1 and 5, with higher scores interpreted as better.	approximately 1 minute
Total Energy (Calories) Selected	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.	approximately 1 minute
Number of Participants Who Selected Sugar-sweetened Beverage	Measured as a dichotomous variable (yes/no) indicating whether participants' hypothetical meal orders include a sugar-sweetened beverage.	approximately 1 minute

Collaborators and Investigators

• Sponsor: Johns Hopkins Bloomberg School of Public Health
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); University of Pennsylvania; University of California, Davis; Harvard School of Public Health (HSPH)
• Investigators: Principal Investigator: Julia Wolfson, PhD MPP, Johns Hopkins Bloomberg School of Public Health

Study record dates

Study Major Dates

• Study Start (Actual): December 2, 2024
• Primary Completion (Actual): December 6, 2024
• Study Completion (Actual): December 6, 2024

Study Registration Dates

• First Submitted: November 5, 2024
• First Submitted That Met QC Criteria: November 6, 2024
• First Posted (Actual): November 7, 2024

Study Record Updates

• Last Update Posted (Actual): January 6, 2026
• Last Update Submitted That Met QC Criteria: January 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: food labeling; choice behavior; climate labeling
• Additional Relevant MeSH Terms: Behavior; Feeding Behavior; Food Preferences; Technology, Industry, and Agriculture; Industry; Product Packaging; Product Labeling
• Other Study ID Numbers: IRB00030419 (Other Identifier: Johns Hopkins Bloomberg School of Public Health IRB); 1R01DK139327-01 (U.S. NIH Grant/Contract)

Drug and device information, study documents

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