Trial Outcomes & Findings for Food Swaps to Improve the Healthfulness and Reduce the Carbon Footprint of Grocery Purchases (NCT NCT06648226)

NCT ID: NCT06648226

Last Updated: 2026-06-01

Results Overview

The study will asses healthfulness of participants' selections as the average Ofcom Nutrient Profiling Model score of the products the participants select in the shopping task. The score ranges from 0 to 100, where higher scores are healthier. Outcome values were calculated as each participant's mean across visits 2 and 3.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

1201 participants

Primary outcome timeframe

1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Results posted on

2026-06-01

Participant Flow

Participant milestones

Participant milestones
Measure
Health Swaps
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Overall Study
STARTED
300
301
300
300
Overall Study
Visit 2
275
280
261
277
Overall Study
Visit 3
260
261
248
262
Overall Study
COMPLETED
279
284
266
279
Overall Study
NOT COMPLETED
21
17
34
21

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Food Swaps to Improve the Healthfulness and Reduce the Carbon Footprint of Grocery Purchases

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Health Swaps
n=300 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=301 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=300 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=300 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Total
n=1201 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=24 Participants
0 Participants
n=24 Participants
0 Participants
n=48 Participants
0 Participants
n=100 Participants
0 Participants
n=201 Participants
Age, Categorical
Between 18 and 65 years
291 Participants
n=24 Participants
298 Participants
n=24 Participants
292 Participants
n=48 Participants
295 Participants
n=100 Participants
1176 Participants
n=201 Participants
Age, Categorical
>=65 years
9 Participants
n=24 Participants
3 Participants
n=24 Participants
8 Participants
n=48 Participants
5 Participants
n=100 Participants
25 Participants
n=201 Participants
Age, Continuous
32.5 years
STANDARD_DEVIATION 12.9 • n=24 Participants
31.5 years
STANDARD_DEVIATION 11.3 • n=24 Participants
31.1 years
STANDARD_DEVIATION 12.4 • n=48 Participants
30.8 years
STANDARD_DEVIATION 12.0 • n=100 Participants
31.5 years
STANDARD_DEVIATION 12.2 • n=201 Participants
Sex/Gender, Customized
Woman
164 Participants
n=24 Participants
157 Participants
n=24 Participants
157 Participants
n=48 Participants
160 Participants
n=100 Participants
638 Participants
n=201 Participants
Sex/Gender, Customized
Man
132 Participants
n=24 Participants
138 Participants
n=24 Participants
141 Participants
n=48 Participants
134 Participants
n=100 Participants
545 Participants
n=201 Participants
Sex/Gender, Customized
Unknown or other
4 Participants
n=24 Participants
6 Participants
n=24 Participants
2 Participants
n=48 Participants
6 Participants
n=100 Participants
18 Participants
n=201 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
27 Participants
n=24 Participants
24 Participants
n=24 Participants
21 Participants
n=48 Participants
23 Participants
n=100 Participants
95 Participants
n=201 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
273 Participants
n=24 Participants
277 Participants
n=24 Participants
279 Participants
n=48 Participants
277 Participants
n=100 Participants
1106 Participants
n=201 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=24 Participants
0 Participants
n=24 Participants
0 Participants
n=48 Participants
0 Participants
n=100 Participants
0 Participants
n=201 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants
n=24 Participants
2 Participants
n=24 Participants
2 Participants
n=48 Participants
2 Participants
n=100 Participants
7 Participants
n=201 Participants
Household Income
$100,000 to $149,999
62 Participants
n=24 Participants
57 Participants
n=24 Participants
64 Participants
n=48 Participants
63 Participants
n=100 Participants
246 Participants
n=201 Participants
Race (NIH/OMB)
Asian
13 Participants
n=24 Participants
11 Participants
n=24 Participants
11 Participants
n=48 Participants
19 Participants
n=100 Participants
54 Participants
n=201 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=24 Participants
0 Participants
n=24 Participants
0 Participants
n=48 Participants
2 Participants
n=100 Participants
2 Participants
n=201 Participants
Race (NIH/OMB)
Black or African American
92 Participants
n=24 Participants
89 Participants
n=24 Participants
96 Participants
n=48 Participants
100 Participants
n=100 Participants
377 Participants
n=201 Participants
Race (NIH/OMB)
White
180 Participants
n=24 Participants
187 Participants
n=24 Participants
181 Participants
n=48 Participants
165 Participants
n=100 Participants
713 Participants
n=201 Participants
Race (NIH/OMB)
More than one race
10 Participants
n=24 Participants
4 Participants
n=24 Participants
7 Participants
n=48 Participants
8 Participants
n=100 Participants
29 Participants
n=201 Participants
Race (NIH/OMB)
Unknown or Not Reported
4 Participants
n=24 Participants
8 Participants
n=24 Participants
3 Participants
n=48 Participants
4 Participants
n=100 Participants
19 Participants
n=201 Participants
Region of Enrollment
United States
300 Participants
n=24 Participants
301 Participants
n=24 Participants
300 Participants
n=48 Participants
300 Participants
n=100 Participants
1201 Participants
n=201 Participants
Household Income
$0 to $49,999
77 Participants
n=24 Participants
95 Participants
n=24 Participants
85 Participants
n=48 Participants
78 Participants
n=100 Participants
335 Participants
n=201 Participants
Household Income
$50,000 to $99,999
121 Participants
n=24 Participants
108 Participants
n=24 Participants
118 Participants
n=48 Participants
128 Participants
n=100 Participants
475 Participants
n=201 Participants
Household Income
$150,000 or more
40 Participants
n=24 Participants
41 Participants
n=24 Participants
33 Participants
n=48 Participants
31 Participants
n=100 Participants
145 Participants
n=201 Participants

PRIMARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will asses healthfulness of participants' selections as the average Ofcom Nutrient Profiling Model score of the products the participants select in the shopping task. The score ranges from 0 to 100, where higher scores are healthier. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Healthfulness of Product Selection
64 score on a scale
Standard Deviation 7.4
60.1 score on a scale
Standard Deviation 6.3
62.6 score on a scale
Standard Deviation 8.1
57.9 score on a scale
Standard Deviation 6.5

PRIMARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the carbon footprint of participants' selections, operationalized as the average carbon footprint (in CO2-equivalents) of the products the participants select in the shopping task. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Carbon Footprint of Participants' Grocery Store Selections
8.1 kg CO2-eq per kg
Standard Deviation 6.6
5.5 kg CO2-eq per kg
Standard Deviation 5.2
5.9 kg CO2-eq per kg
Standard Deviation 5.2
9.6 kg CO2-eq per kg
Standard Deviation 7

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average calorie density of participants' grocery selections, calculated as the average kcal per 100g of the selected products. Higher values will indicate higher calorie density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Calorie Density of Participants' Grocery Selections
166.8 kcal per 100g
Standard Deviation 68.4
182.2 kcal per 100g
Standard Deviation 65.5
175.7 kcal per 100g
Standard Deviation 75.8
200.5 kcal per 100g
Standard Deviation 68.4

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average sugar density of participants' grocery selections, calculated as the average grams of sugar per 100g of the selected products. Higher values will indicate higher sugar density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Sugar Density of Participants' Grocery Selections
6.4 g per 100g
Standard Deviation 5.8
6.9 g per 100g
Standard Deviation 5.3
6.4 g per 100g
Standard Deviation 5.3
8 g per 100g
Standard Deviation 5.8

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average sodium density of participants' grocery selections, calculated as the average milligrams of sodium per 100g of the selected products. Higher values will indicate higher sodium density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Sodium Density of Participants' Grocery Selections
264.1 mg per 100g
Standard Deviation 163
314.4 mg per 100g
Standard Deviation 188.4
284.7 mg per 100g
Standard Deviation 158.1
317.3 mg per 100g
Standard Deviation 175.4

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average saturated fat density of participants' grocery selections, calculated as the average grams of saturated fat per 100g of the selected products. Higher values will indicate higher saturated fat density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Saturated Fat Density of Participants' Grocery Selections
2.3 g per 100g
Standard Deviation 1.4
2.7 g per 100g
Standard Deviation 1.8
2.4 g per 100g
Standard Deviation 2
3.4 g per 100g
Standard Deviation 1.7

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average fiber density of participants' grocery selections, calculated as the average grams of fiber per 100g of the selected products. Higher values will indicate higher fiber density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Fiber Density of Participants' Grocery Selections
1.3 g per 100g
Standard Deviation 1.1
1.1 g per 100g
Standard Deviation 0.8
1.3 g per 100g
Standard Deviation 0.9
1.1 g per 100g
Standard Deviation 0.7

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the average protein density of participants' grocery selections, calculated as the average grams of protein per 100g of the selected products. Higher values will indicate higher protein density. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Protein Density of Participants' Grocery Selections
7.1 g per 100g
Standard Deviation 2.8
6.6 g per 100g
Standard Deviation 2.8
7.1 g per 100g
Standard Deviation 3.1
7.2 g per 100g
Standard Deviation 2.9

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess the total amount participants spent on their grocery selections in United States dollars. Higher values will indicate greater spending. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Total Spending on Participants' Grocery Selections
44.9 US Dollars
Standard Deviation 7.5
44.4 US Dollars
Standard Deviation 7.2
44.2 US Dollars
Standard Deviation 7.8
45.8 US Dollars
Standard Deviation 6.4

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess thinking about health using 1 item: "We are interested in how you selected products while you were grocery shopping. When you selected foods, how much did you think about each of the following characteristics? ... health." Response options range from "Not at all" (1) to "A great deal" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Thinking About Health
3.9 score on a scale
Standard Deviation 1
3.9 score on a scale
Standard Deviation 1
4 score on a scale
Standard Deviation 1
3.7 score on a scale
Standard Deviation 1.1

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess thinking about climate impact using 1 item: "We are interested in how you selected products while you were grocery shopping. When you selected foods, how much did you think about each of the following characteristics? ... climate impact." Response options range from "Not at all" (1) to "A great deal" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Thinking About Climate Impact
2.6 score on a scale
Standard Deviation 1.3
3.5 score on a scale
Standard Deviation 1.3
3.3 score on a scale
Standard Deviation 1.2
2.6 score on a scale
Standard Deviation 1.3

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess thinking about taste using 1 item: "We are interested in how you selected products while you were grocery shopping. When you selected foods, how much did you think about each of the following characteristics? ... taste." Response options range from "Not at all" (1) to "A great deal" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Thinking About Taste
4.4 score on a scale
Standard Deviation 0.7
4.4 score on a scale
Standard Deviation 0.7
4.4 score on a scale
Standard Deviation 0.6
4.4 score on a scale
Standard Deviation 0.6

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess negative emotional reactions using 3 items: "While you were shopping, how much did you feel…" "worried", "guilty," "ashamed"? Response options range from "Not at all" (1) to "Extremely" (5). The investigators will average the 3 items; higher average scores indicate stronger negative emotional reactions. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Negative Emotional Reactions While Shopping
1.4 score on a scale
Standard Deviation 0.5
1.3 score on a scale
Standard Deviation 0.5
1.4 score on a scale
Standard Deviation 0.6
1.3 score on a scale
Standard Deviation 0.5

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess positive emotional reactions using 3 items: "While you were shopping, how much did you feel…" "inspired", "proud," "reassured"? Response options range from "Not at all" (1) to "Extremely" (5). The investigators will average the 3 items; higher average scores indicate stronger positive emotional reactions. Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Positive Emotional Reactions While Shopping
3.2 score on a scale
Standard Deviation 1.2
3.2 score on a scale
Standard Deviation 1.2
3.2 score on a scale
Standard Deviation 1.2
3.2 score on a scale
Standard Deviation 1.1

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess injunctive norms to buy healthy foods with 1 item: "People who are important to me think I should buy healthy foods." Response options range from "Strongly disagree" (1) to "Strongly agree" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Injunctive Norms to Buy Healthy Foods
4.3 score on a scale
Standard Deviation 0.8
4.3 score on a scale
Standard Deviation 0.7
4.3 score on a scale
Standard Deviation 0.7
4.3 score on a scale
Standard Deviation 0.8

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess descriptive norms to buy healthy foods with 1 item: "Most shoppers buy healthy foods when they are shopping for groceries." Response options range from "Strongly disagree" (1) to "Strongly agree" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Descriptive Norms to Buy Healthy Foods
3.4 score on a scale
Standard Deviation 1.1
3.4 score on a scale
Standard Deviation 1.0
3.4 score on a scale
Standard Deviation 1.1
3.4 score on a scale
Standard Deviation 1.0

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess injunctive norms to buy foods with low climate impact with 1 item: "People who are important to me think I should buy foods with low climate impact." Response options range from "Strongly disagree" (1) to "Strongly agree" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Injunctive Norms to Buy Foods With Low Climate Impact
3.4 score on a scale
Standard Deviation 1.2
3.4 score on a scale
Standard Deviation 1.1
3.4 score on a scale
Standard Deviation 1.1
3.2 score on a scale
Standard Deviation 1.1

SECONDARY outcome

Timeframe: 1-week follow-up (visit 2), and 2-week follow-up (visit 3)

Population: Analysis population included participants with nonmissing outcome data at visit 2 and/or visit 3.

The study will assess descriptive norms to buy foods with lower climate impact with 1 item: "Most shoppers buy foods with low climate impact when they are shopping for groceries." Response options range from "Strongly disagree" (1) to "Strongly agree" (5). Outcome values were calculated as each participant's mean across visits 2 and 3.

Outcome measures

Outcome measures
Measure
Health Swaps
n=279 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=284 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=266 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=279 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Descriptive Norms to Buy Foods With Low Climate Impact
2.8 score on a scale
Standard Deviation 1.2
2.9 score on a scale
Standard Deviation 1.1
2.8 score on a scale
Standard Deviation 1.1
2.7 score on a scale
Standard Deviation 1.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess perceived helpfulness of nutrition labels with 1 item: "These labels would help me choose healthier foods." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Perceived Helpfulness of Nutrition Labels
4.1 score on a scale
Standard Deviation 1.0
4.0 score on a scale
Standard Deviation 1.1
4.1 score on a scale
Standard Deviation 1.1
4.1 score on a scale
Standard Deviation 1.0

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess perceived helpfulness of climate labels with 1 item: "These labels would help me choose foods with lower climate impact." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Perceived Helpfulness of Climate Labels
3.8 score on a scale
Standard Deviation 1.2
4.0 score on a scale
Standard Deviation 1.2
3.9 score on a scale
Standard Deviation 1.2
3.8 score on a scale
Standard Deviation 1.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess perceived helpfulness of health swap recommendations with 1 item: "This type of recommendation would help me choose healthier foods." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Perceived Helpfulness of Health Swap Recommendations
4.2 score on a scale
Standard Deviation 1.0
4.0 score on a scale
Standard Deviation 1.2
4.1 score on a scale
Standard Deviation 1.1
4.1 score on a scale
Standard Deviation 1.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess perceived helpfulness of climate swap recommendations with 1 item: "This type of recommendation would help me choose more foods with lower climate impact." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Perceived Helpfulness of Climate Swap Recommendations
3.8 score on a scale
Standard Deviation 1.3
3.9 score on a scale
Standard Deviation 1.2
3.9 score on a scale
Standard Deviation 1.2
3.9 score on a scale
Standard Deviation 1.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess liking of nutrition labels with 1 item: "I like these labels." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Liking of Nutrition Labels
4.1 score on a scale
Standard Deviation 1.1
3.9 score on a scale
Standard Deviation 1.2
4.0 score on a scale
Standard Deviation 1.1
3.9 score on a scale
Standard Deviation 1.0

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess liking of climate labels with 1 item: "I like these labels." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Liking of Climate Labels
3.7 score on a scale
Standard Deviation 1.3
3.8 score on a scale
Standard Deviation 1.3
3.8 score on a scale
Standard Deviation 1.2
3.7 score on a scale
Standard Deviation 1.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess liking health swap recommendations with 1 item: "I like these recommendations." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Liking of Health Swap Recommendations
4.0 score on a scale
Standard Deviation 1.2
4.0 score on a scale
Standard Deviation 1.2
3.9 score on a scale
Standard Deviation 1.2
4.0 score on a scale
Standard Deviation 1.1

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess liking climate swap recommendations with 1 item: "I like these recommendations." Response options range from "Not at all" (1) to "A great deal" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Liking of Climate Swap Recommendations
3.7 score on a scale
Standard Deviation 1.4
3.7 score on a scale
Standard Deviation 1.3
3.8 score on a scale
Standard Deviation 1.3
3.8 score on a scale
Standard Deviation 1.2

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess acceptability of the nutrition labels with 1 item: "How much would you approve or disapprove of these labels being displayed on foods sold in grocery stores?" Response options range from "Strongly disapprove" (1) to "Strongly approve" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Acceptability of Nutrition Labels
4.4 score on a scale
Standard Deviation 0.9
4.3 score on a scale
Standard Deviation 0.9
4.3 score on a scale
Standard Deviation 0.8
4.3 score on a scale
Standard Deviation 0.8

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess acceptability of the climate labels with 1 item: "How much would you approve or disapprove of these labels being displayed on foods sold in grocery stores?" Response options range from "Strongly disapprove" (1) to "Strongly approve" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Acceptability of Climate Labels
4.1 score on a scale
Standard Deviation 1.1
4.2 score on a scale
Standard Deviation 1.0
4.2 score on a scale
Standard Deviation 0.9
4.2 score on a scale
Standard Deviation 0.9

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess acceptability of the health swap recommendations with 1 item: "How much would you approve or disapprove of these recommendations being offered by grocery stores?" Response options range from "Strongly disapprove" (1) to "Strongly approve" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Acceptability of Health Swap Recommendations
4.4 score on a scale
Standard Deviation 0.8
4.3 score on a scale
Standard Deviation 1.0
4.3 score on a scale
Standard Deviation 0.9
4.3 score on a scale
Standard Deviation 0.9

OTHER_PRE_SPECIFIED outcome

Timeframe: Assessed at 2-week follow-up (visit 3)

Population: Participants with nonmissing visit 3 outcome data only; these outcomes were assessed at visit 3 only.

The study will assess acceptability of the climate swap recommendations 1 item: "How much would you approve or disapprove of these recommendations being offered by grocery stores?" Response options range from "Strongly disapprove" (1) to "Strongly approve" (5).

Outcome measures

Outcome measures
Measure
Health Swaps
n=260 Participants
Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade. Health swaps: Participants will view "health grade" labels on all products in the online grocery store indicating their healthfulness as estimated by United Kingdom Ofcom Nutrient Profiling Model scores. The health score labels will mimic Nutri-Score labels, a labeling system used in some European countries, showing a color-coded grade of "A" (green) through "F" (red) on each product. Products with "A" and "B" labels will meet the United Kingdom's cutoff for products that can be marketed to children and "C", "D" and "F" labels products are less healthy than this cutoff (based on tertiles of Ofcom scores within each food group). When participants attempt to add a less healthy product to their cart (e.g., "C," "D" or "F" health label), the store will automatically suggest a healthier product from the same category (e.g., with a "A" or "B" health label).
Climate Swaps
n=260 Participants
Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade. Climate swaps: Participants will view "climate grade" labels on all products indicating their climate impact. The climate impact is calculated as the greenhouse gas emissions associated with producing the product in carbon dioxide equivalents (CO2-eq) per 100g (i.e., "carbon footprint"). Labels will be applied based on quintiles of carbon footprints in each food group. When participants attempt to add a high-climate-impact product to their cart (e.g., with a "C," "D," or "F" climate label), the store will automatically offer them swaps to more climate-friendly products (e.g., with a "A" or "B" climate label).
Combined Health and Climate Swaps
n=248 Participants
Labels will be "nutrition grades" and "climate grades" for products and replacement swap suggestions will be for items that are better than originally selected products on at least one dimension (nutrition grade or climate grade) and not worse than originally selected products on either dimension. Combined health and climate swaps: Participants will view both the health and climate grade labels on all products in the online grocery store. When participants attempt to select a product with a "C," "D," or "F" label on either dimension to their cart, the store will automatically offer them swaps to products that offer improvement over the original food on at least 1 dimension (health or climate-friendliness) and were at least as good or better on the other dimension, with the additional guardrail that the store never suggests products with a "C," "D" or "F" label on either dimension.
Control
n=262 Participants
No labels or swaps. Control: Participants will not view any extra labels or be offered any swaps in the online grocery store.
Acceptability of Climate Swap Recommendations
4.0 score on a scale
Standard Deviation 1.1
4.1 score on a scale
Standard Deviation 1.1
4.1 score on a scale
Standard Deviation 1.0
4.1 score on a scale
Standard Deviation 1.0

Adverse Events

Health Swaps

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Climate Swaps

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Combined Health and Climate Swaps

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Control

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Anna Grummon

Stanford University

Phone: 6506447366

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place