Clinical trial NCT06648226: Food Swaps to Improve the Healthfulness and Reduce the Carbon Footprint of Grocery Purchases
Official title: A Randomized Trial of Food Swaps to Improve the Healthfulness and Reduce the Carbon Footprint of Grocery Purchases
Study type: INTERVENTIONAL
Overall status: ENROLLING_BY_INVITATION
Phase: NA
Conditions: Food Selection
Nutrition
Food Preferences
Dietary Habits
Sustainability
Healthy Diet
Keywords: food choices
climate
dietary substitutions
diet
Lead sponsor: Stanford University
Sponsor class: OTHER
Collaborators: name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2024-10-18
Enrollment: 1200
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Healthfulness of product selection
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Carbon footprint of participants' grocery store selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
Secondary outcomes:
measure: Calorie density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Sugar density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Sodium density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Saturated fat density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Fiber density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Protein density of participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Total spending on participants' grocery selections
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Thinking about health
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Thinking about climate impact
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Thinking about taste
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Negative emotional reactions while shopping
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Positive emotional reactions while shopping
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Injunctive norms to buy healthy foods
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Descriptive norms to buy healthy foods
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Injunctive norms to buy foods with low climate impact
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
measure: Descriptive norms to buy foods with low climate impact
timeFrame: Assessed at baseline, 1-week follow-up, and 2-week follow-up
Other outcomes:
measure: Perceived helpfulness of nutrition labels
timeFrame: Assessed at 2-week follow-up
measure: Perceived helpfulness of climate labels
timeFrame: Assessed at 2-week follow-up
measure: Perceived helpfulness of health swap recommendations
timeFrame: Assessed at 2-week follow-up
measure: Perceived helpfulness of climate swap recommendations
timeFrame: Assessed at 2-week follow-up
measure: Liking of nutrition labels
timeFrame: Assessed at 2-week follow-up
measure: Liking of climate labels
timeFrame: Assessed at 2-week follow-up
measure: Liking of health swap recommendations
timeFrame: Assessed at 2-week follow-up
measure: Liking of climate swap recommendations
timeFrame: Assessed at 2-week follow-up
measure: Acceptability of nutrition labels
timeFrame: Assessed at 2-week follow-up
measure: Acceptability of climate labels
timeFrame: Assessed at 2-week follow-up
measure: Acceptability of health swap recommendations
timeFrame: Assessed at 2-week follow-up
measure: Acceptability of climate swap recommendations
timeFrame: Assessed at 2-week follow-up
Locations:
city: Palo Alto
country: United States
facility: Stanford School of Medicine
state: California
Study officials:
affiliation: Stanford School of Medicine
name: Anna H. Grummon, PhD
role: PRINCIPAL_INVESTIGATOR
References: