Understanding Food Choices

February 2, 2021 updated by: Eric A. Finkelstein, Duke-NUS Graduate Medical School

Multiphase Optimal Strategy To Improve Diet Quality-MOSTDQ (Aim 1)

This study aims to use the Multiphase Optimization Strategy (MOST) to build and optimize a multi-component intervention that improves diet quality. The investigators will evaluate the effects of evidence-based public health interventions on consumers' diet quality via a web-based grocery store "NUSMart" and then identify a multi-component intervention that includes only those interventions meaningfully affecting diet quality.

Study Overview

Detailed Description

The important role that diet plays in health and disease is well established. Excessive intake of energy, saturated fat and sodium increase the risk of heart disease, diabetes and certain cancers. As a result, interventions aimed at encouraging healthier food consumption have been pursued by many countries. These can be broadly grouped into the following categories: price manipulations, food labeling, and behavioral nudges.

No study has previously assessed the potentially interactive effects of a multi-component intervention that incorporates the strongest features of each intervention component while discarding those that do not meaningfully contribute to healthier consumption. That is the goal of this effort.

To this end, the investigators chose a full-factorial design because this experimental design allows us to estimate not only the independent (main) effects of the interventions but also their interaction effects. The full-factorial design includes all possible combinations of the interventions' status. Because the investigators have four interventions, each of which has two levels (intervention On or Off), there are 16 (i.e. 2^4) experimental conditions/arms in total. The four interventions for this study are outlined below:

- Explicit Tax: To impose an explicit tax on food and beverage items that are eligible for red stop-sign (explained in b.) as less healthy foods.

Foods and Beverages: The investigators will impose a 20% tax on sales price of the food items.

  • Food Labels (with the summary of healthiness of shopping baskets & targets): To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'Unhealthy choice' food label to items with Nutri-Score "D" and "E". In the presence of food labels, before shopping, subjects will watch a video briefly explaining the food labels on the store and be provided a live visual indicator of the healthiness of shoppers' current basket (called "My Cart Summary") with the recommended healthy baskets goals (i.e., Green logo products ≥ 60% and Red logo products ≤ 15% of the weighted number of servings of products.). My Cart Summary will be displayed as a pie chart with the proportion of servings in their current shopping baskets, according to the three food labels. This way, as shoppers add to their basket while browsing the store, they will have visual feedback on how their latest addition contributes to their total basket healthiness.
  • Ordering: To order food items by Nutri-Score such that healthier items are shown upfront on NUSMart.
  • Within Group Substitution: At the checkout, to provide consumers with an opportunity to replace their original items with an item chosen from two or four recommended substitutes that are healthier within their corresponding food categories based on the similarities of price, ingredients, flavor, and other characteristics.

Participants will be randomly assigned to one of the 16 arms and instructed to perform a one-time hypothetical grocery shopping on NUSMart.

The investigators will collect participants' demographic and health characteristics as well as hunger at the time of the survey and their self-control in the baseline survey. The collected data will be used to precisely estimate the causal effect of the interventions and address their underlying mechanism to change consumers' food choices.

Our hypotheses about the effects of the interventions on diet quality, measured by the weighted average Nutri-Score (primary) of finalized shopping baskets, are as follows:

  1. There will be significant and positive main effects of each of the interventions.
  2. There will be significant and positive interaction effects on diet quality of: Explicit tax & food labels, Food labels & ordering.

We will also run models both with and without including covariates that include demographic variables (e.g., age, minority status, income, BMI, sex, and household size) and measurements of self-control, hunger, and health-status. To test the moderating effects of hunger, self-control, health-status, and education level, we will include interaction terms between the intervention arms and these variables.

Study Type

Interventional

Enrollment (Actual)

756

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Singapore, Singapore, 169857
        • Duke-NUS Medical School

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Singapore Resident
  • Age 21 and above
  • Must be the primary weekly grocery shopper in their household

Exclusion Criteria:

  • Non-Singapore resident
  • Less than 21 years old
  • Non-primary grocery shopper in their household

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
Tax (ON) Food Labels (ON) Ordering (ON) Substitution (ON)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To order food items by Nutri-Score (high to low).
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 2
Tax (ON) Food Labels (ON) Ordering (ON) Substitution (OFF)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To order food items by Nutri-Score (high to low).
Experimental: 3
Tax (ON) Food Labels (ON) Ordering (OFF) Substitution (ON)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 4
Tax (ON) Food Labels (ON) Ordering (OFF) Substitution (OFF)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
Experimental: 5
Tax (ON) Food Labels (OFF) Ordering (ON) Substitution (ON)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To order food items by Nutri-Score (high to low).
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 6
Tax (ON) Food Labels (OFF) Ordering (ON) Substitution (OFF)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To order food items by Nutri-Score (high to low).
Experimental: 7
Tax (ON) Food Labels (OFF) Ordering (OFF) Substitution (ON)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 8
Tax (ON) Food Labels (OFF) Ordering (OFF) Substitution (OFF)

To impose an explicit tax on food and beverage items that are eligible for red stop-sign food logos (explained in Intervention 2) as less healthy foods. Explicit tax shows pre-tax prices and a label indicating that the price includes a corresponding tax on the less healthy products.

Food and Beverages: we will impose a 20% tax on sales price of the food items

Experimental: 9
Tax (OFF) Food Labels (ON) Ordering (ON) Substitution (ON)

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To order food items by Nutri-Score (high to low).
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 10
Tax (OFF) Food Labels (ON) Ordering (ON) Substitution (OFF)

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To order food items by Nutri-Score (high to low).
Experimental: 11
Tax (OFF) Food Labels (ON) Ordering (OFF) Substitution (ON)

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 12
Tax (OFF) Food Labels (ON) Ordering (OFF) Substitution (OFF)

To provide the green circle 'healthy choice' food label to items with Nutri-Score "A" and "B", the amber circle 'in between healthy and unhealthy choice' food label to items with Nutri-Score "C", and the red stop-sign 'less healthy choice' food label to items with Nutri-Score "D" and "E".

In the presence of food labels,

  • Video: subjects will watch a video briefly explaining the food labels on the store.
  • My Cart Summary: subjects will be provided a live visual indicator of the healthiness of shoppers' current basket with the recommended healthy baskets goals.
Experimental: 13
Tax (OFF) Food Labels (OFF) Ordering (ON) Substitution (ON)
To order food items by Nutri-Score (high to low).
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
Experimental: 14
Tax (OFF) Food Labels (OFF) Ordering (ON) Substitution (OFF)
To order food items by Nutri-Score (high to low).
Experimental: 15
Tax (OFF) Food Labels (OFF) Ordering (OFF) Substitution (ON)
To provide substitutes within corresponding food categories that are better than the items that subjects chose in terms of Nutri-Score based on the similarities of price, primary ingredients, flavor, and other characteristics.
No Intervention: 16
Tax (OFF) Food Labels (OFF) Ordering (OFF) Substitution (OFF)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diet Quality
Time Frame: At the end of data collection, up to 8 weeks
Diet quality measured by the weighted average of all purchased products' Nutri-Score for the shopping trip. Nutri-Score is an individual dietary index based on the British Food Standard Agency Nutrient Profiling System.
At the end of data collection, up to 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of products
Time Frame: At the end of data collection, up to 8 weeks
The proportion of products eligible for the green circle label and the red stop-sign label respectively, of the purchased products.
At the end of data collection, up to 8 weeks
Average nutrients per serving
Time Frame: At the end of data collection, up to 8 weeks
Average calories, sodium, sugar, fat, and saturated fat per serving, which will be calculated based on all purchased products' total nutritional value.
At the end of data collection, up to 8 weeks

Collaborators and Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 2, 2020

Primary Completion (Actual)

December 14, 2020

Study Completion (Actual)

December 14, 2020

Study Registration Dates

First Submitted

November 2, 2020

First Submitted That Met QC Criteria

November 11, 2020

First Posted (Actual)

November 17, 2020

Study Record Updates

Last Update Posted (Actual)

February 4, 2021

Last Update Submitted That Met QC Criteria

February 2, 2021

Last Verified

February 1, 2021

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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