Targeted Food Incentives to Improve Diet Quality and Health Among Adults

Study Overview
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Brief Summary
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The purpose of this study is to test whether individual-level targeted price incentives for healthier foods can improve the diet quality of grocery purchases made by adults in comparison to a one size fits all approach. To test this, the investigators plan to implement a 8-month randomized controlled cross-over trial. The intervention group will receive a small discount for using their loyalty card and weekly coupons for healthier foods (e.g. fruits, vegetables, whole grains, lean meats and seafood, low-fat dairy) that are selected based on the individual's past purchase history, dietary preferences, their baseline diet quality, and their estimated likelihood of using the coupon. Individualized coupons will be automatically sent to customers' loyalty cards each week, and separate emails with appropriate nutrition education and information about the coupons will be sent to participants weekly. The control group will receive a small discount for using their loyalty cards during the first phase of the study (3-months), occasional untargeted coupons, and weekly emails with untargeted nutrition education. Following phase1, there will be a 2-month washout period, and then the intervention and control groups will cross over for the remaining 3-months of the study. The investigators will collect purchase data from all participants as well as food frequency questionnaires and other self-reported behavioral and health questions at baseline, after phase 1 completion, and after phase 2 completion. The investigators hypothesize that participants in the intervention group will meaningfully improve the overall quality of their food purchases (measured using the Grocery Purchase Quality Index-2016) as well as their overall diet quality (measured using the Healthy Eating Index 2010.

Detailed Description
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A detailed description of Eligibility and outcome measures is entered elsewhere

Official Title
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Individually-targeted Incentives, Diet Quality, and Health Outcomes Among Adults

Conditions
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Diet Modification, Diet Habit

Intervention / Treatment
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* Behavioral: Targeted incentives
* Behavioral: Nominal loyalty card discount and nutrition education


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Speaks English Non-store employee Primary shopper in the household Purchases at least half of weekly groceries at supermarket Not pregnant or planning on becoming pregnant before April 2019 Exclusion Criteria: Younger than 18 years of age Does not speak English Employee at supermarket Pregnant or planning to become pregnant before April 2019 Not primary shopper for household Purchases less than half of weekly groceries at supermarket

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Targeted incentives arm<br>The interventions received by the experimental group include: 1) weekly emails with targeted coupons for healthier products, 2) weekly emails with targeted nutrition education, and 3) and a nominal discount on grocery purchases for using their loyalty card | Behavioral: Targeted incentives<br>* Participants receiving individually-targeted incentives will receive weekly coupons for healthier foods that are informed by their purchase history, responses to behavioral and health questions, food preferences, and need for improvement in different categories<br>Behavioral: Nominal loyalty card discount and nutrition education<br>* All participants will receive a nominal discount on all groceries for using their loyalty card and nutrition education through weekly emails.<br>|
| Active Comparator: Usual care arm<br>The interventions included under usual care include 1) untargeted nutrition education, 2) occasional untargeted coupons for healthier products, and 3) a nominal discount on their grocery purchases for using their loyalty card. These interventions are only received by participants randomized to the usual care arm (rather than the entire population of shoppers), and will allow for testing whether targeting discounts and nutrition education improves the diet quality of purchases in comparison to untargeted approaches. | Behavioral: Nominal loyalty card discount and nutrition education<br>* All participants will receive a nominal discount on all groceries for using their loyalty card and nutrition education through weekly emails.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Likelihood of purchasing targeted products | Within produce, whole grain cereals & breads, lean meats, low-fat dairy, and beverages, will look at the proportion of expenditures (i.e. percent of dollars) in those categories before and after the intervention between treatment and control group. | 3- 6- and 9-month changes within and between the intervention and control groups | 
| Grocery Purchase Quality Index (GPQI) 2016 | The GPQI is a validated measure for scoring the quality of household grocery purchases by comparing the percent spent within different food categories with recommended spending. https://utah.pure.elsevier.com/en/publications/the-grocery-purchase-quality-index-2016-an-innovative-approach-to | 3, 6- and 9-month changes in the GPQI-16 and its components within and between the intervention and control groups | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Healthy Eating Index (HEI) -2010 for the primary shopper | The HEI-10 is a validated measure of individual-level diet quality that measures compliance with US Dietary recommendations. https://www.ncbi.nlm.nih.gov/pubmed/24453128 | 3, 6- and 9-month changes in the HEI-10 and its components within and between the intervention and control groups | 
| Percent expenditures within targeted categories | The investigators will compute the percent of shopping dollars people spend in fruits, vegetables, whole grains, dairy, lean meat, and seafood. | 3, 6- and 9-month changes in percent spending in targeted categories within and between the intervention and control groups | 
| Self-reported height and weight used to compute body mass index (BMI) | The investigators will compute body mass index from self-reported weight in pounds and height in inches (weight (lbs) * 703/height (in)/height (in) | 3, 6- and 9-month changes in BMI |