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

Stanford University

Status: Completed

Conditions: Dietary Habits; Food Selection; Sustainability; Nutrition; Healthy Diet; Food Preferences

Treatments: Behavioral: Combined health and climate swaps; Behavioral: Climate swaps; Behavioral: Health swaps; Behavioral: Control

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT06648226

76925

K01HL158608 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The study aims to determine whether viewing health or climate labels (or both) and receiving recommendations for healthier or more climate-friendly swaps (or both) in an online grocery store environment improves the healthfulness and reduces the carbon footprint of consumers' food and beverage purchases compared to shopping as usual without swap recommendations. The online store will record participants' food selections. Participants will also be asked to complete survey measures.

Full description

Participants will complete an online between-subjects randomized experiment. The experiment will involve three study visits.

In the first study visit, participants will complete an online grocery store shopping task without intervention. Participants will be given a budget of $50 and asked to shop as they normally would. The store will record participants' food selections. After completing the shopping task, participants will complete an online survey.

Approximately one week later, participants will complete a second study visit with the same instructions. They will be randomized to 1 of 4 conditions (1) health only, 2) climate only, 3) combined health and climate, 4) control. In the health only condition, participants will view labels with nutrition grades and may be directed to swap their selections for healthier items. In the climate only condition, participants will view labels with climate grades and may be directed to swap their selections for more climate-friendly (lower-carbon-footprint) items. In the combined health and climate condition, participants will view labels with health and climate grades and may be directed to swap their selections for healthier or more climate-friendly items. In the control group, participants will not view any labels or swaps. The store will record participants' selections. After completing the shopping task, participants will complete an online survey.

In the third study visit, the participants will maintain their assigned group and will be asked to repeat the same tasks as in the second visit.

Enrollment: 1,201 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Aged 18 years or older
• Reside in the United States
• Able to complete a survey in English
• Have internet access to complete the 3 online study visits

Exclusion criteria

• Under the age of 18
• Reside outside of the United States
• Unable to complete a survey in English
• Do not have internet access to complete the 3 online study visits

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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1,201 participants in 4 patient groups

Health swaps

Experimental group

Description:

Labels will be "nutrition grades" for products and replacement swap suggestions will be for items with a better nutrition grade.

Treatment:

Behavioral: Health swaps

Climate swaps

Experimental group

Description:

Labels will be "climate grades" for products and replacement swap suggestions will be for items with a better climate grade.

Treatment:

Behavioral: Climate swaps

Combined health and climate swaps

Experimental group

Description:

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.

Treatment:

Behavioral: Combined health and climate swaps

Control

Active Comparator group

Description:

No labels or swaps.

Treatment:

Behavioral: Control