Translating Research-Funded Mobile Produce Market Trials Into Sustained Public Health Programs

Abstract

Food on the Move is an ongoing mobile produce market program in Rhode Island whose operations evolved from previous mobile market programs evaluated by 2 research studies: (1) one on Fresh to You, a prospective cohort study evaluating markets at community sites serving low-income families; and (2) one on Live Well, Viva Bien, a cluster randomized controlled trial evaluating markets and complementary nutrition interventions at public housing sites. The 2 studies spanned more than a decade and demonstrated the effect of mobile produce markets on access to, affordability of, and consumption of fruit and vegetables in low-income communities in Rhode Island. When grant funding ended in 2016, academic and community partners continued the mobile market program as Food on the Move. The Rhode Island Public Health Institute adopted the program model and developed a business plan to maximize market efficiency. To address price as a barrier to buying fruit and vegetables, the Institute implemented an innovative incentive program for purchases made with Supplemental Nutrition Assistance Program (SNAP) benefits, funded by a federal Food Insecurity Nutrition Incentive grant program. In 2018, Food on the Move sold more than $160 000 in produce at 335 markets, more than $50 000 of which came from these SNAP incentive programs. For sustained change in communities, researchers and community partners need examples of how to translate findings from research trials into public health practice. Food on the Move serves as a case study for the successful transition of community-focused research into a sustainable and scalable evidence-based program.

Poor diet quality is one of the most salient risk factors for chronic disease, including obesity, type 2 diabetes, cancer, and cardiovascular disease. ¹ In 2017, 166 deaths per 100 000 people in the United States were attributable to poor diet quality. ² Alternatively, a diet rich in fruit and vegetables can help reduce the risk of weight gain, ³ certain types of cancer, ⁴ type 2 diabetes, and cardiovascular disease ⁵ and ensure an adequate intake of most micronutrients and dietary fiber. ⁶ However, only 1 in 10 people in the United States currently meets the recommendations for fruit and vegetable intake as outlined in the Dietary Guidelines for Americans. ⁷

The prevalence of diet-related chronic diseases such as obesity and type 2 diabetes ^7,8 is substantially higher in the United States among Hispanic people, Black people, ^9,10 and people in low socioeconomic status (SES) groups, ¹¹ who also have lower fruit and vegetable consumption, compared with non-Hispanic White people and people in high-SES groups. ^12,13 These disparities are often attributed to access to grocery stores, household income, and costs of healthier foods. ^14,15 Low-income and racially/ethnically diverse neighborhoods often lack full-service grocery stores and farmers’ markets, thereby limiting the availability and accessibility of healthy foods, including fruit and vegetables. ¹⁶ A systematic review of the association between SES and diet quality concluded that higher-quality diets that are adequate in fruit and vegetables are more expensive on a per-calorie basis than lower-quality diets are. ¹⁷ Multiple dimensions of food access, including availability, affordability, and accessibility, are associated with consuming higher-quality diets that are rich in fruit and vegetables. ¹⁸ Public health interventions, such as mobile produce markets, aim to improve the availability, accessibility, and affordability of fruit and vegetables among low-income communities in the United States. ¹⁹

In 2018, the National Institutes of Health spent $8.5 billion on disease prevention and $3.3 billion on health disparities research. ²⁰ Although some findings from this research funding will improve the health of people in the United States, community-based interventions that target health-related disparities are often not maintained after research funding ends, regardless of their proven effectiveness and acceptability, because of financial barriers. ²¹ Given the substantial time and cost of these community-based research studies, examples of how evidence-based approaches transition into sustainable community programs are limited. We describe 2 large-scale community-based research projects, Fresh to You ²² and Live Well, Viva Bien, ^23,24 which evaluated the effects of mobile produce markets on access to and consumption of fruit and vegetables and their successful transition to a sustained public health service program, Food on the Move.

Funded Research

Fresh to You: A Cohort Study

Fresh to You began in 2006 as a public–private partnership among the Rhode Island Department of Health, Brown University School of Public Health, and a local produce distributor through funding from the Centers for Disease Control and Prevention. In this first iteration of the mobile market model, Fresh to You offered year-round produce markets that sold high-quality, fresh fruit and vegetables at discounted prices at a community agency, which served a low-income community that did not have a grocery store. Data from exit interviews with market customers supported the need for the market and served as the basis for a grant from the Robert Wood Johnson Foundation Healthy Eating Research Program to more formally evaluate the Fresh to You program. The grant began in 2008 with aims to (1) evaluate the feasibility and acceptability of Fresh to You in various community organizations and (2) evaluate whether Fresh to You increases fruit and vegetable consumption among children aged 3-13 years from racially/ethnically diverse backgrounds and low-income households. ²² The local produce distributor brought Fresh to You “mobile” markets to 6 community-based sites (3 elementary schools, 1 middle school, 1 job training site, and 1 community health center) weekly for 5 months at each site. The markets were considered “mobile” in that they were set up and taken down either inside or outside each site and moved to a subsequent site daily. The mobile markets sold 23 fresh produce items (eg, spinach, strawberries, bananas) at a 15% to 25% discount from grocery store prices and accepted Supplemental Nutrition Assistance Program (SNAP) benefits for payment. ²²

To evaluate the effectiveness of Fresh to You, 480 parent–child dyads (with children aged 3-13 y) participated in a longitudinal cohort, including a baseline and follow-up survey at 5 months. Parents were mostly female (91.5%) and Hispanic (59.2%); 79% (n = 378) were retained at the 5-month follow-up. The study found that parent-reported children’s fruit and vegetable consumption increased by 0.48 cups per day from baseline to 5 months (P < .001), with increases for both fruit, excluding fruit juice (0.2 cups/day, P = .003), and vegetables, excluding potatoes (0.28 cups/day, P = .001). ²² Parents reported high levels of satisfaction with the market’s convenience and the quality and variety of produce. However, follow-up qualitative data from focus groups with a subgroup of parents suggested that produce cost was the single most important barrier to increasing consumption of fruit and vegetables. Additional suggestions for improvement included selling more culturally desired produce (eg, plantains, yucca, mangos) and providing educational activities. ²² These recommendations informed the next stage of evaluating the mobile produce market.

The Live Well, Viva Bien Cluster Randomized Controlled Trial

A cluster randomized controlled trial, Live Well, Viva Bien, was funded by the National Cancer Institute in 2010. Live Well, Viva Bien was designed to test the effectiveness of a mobile market along with educational activities on improving fruit and vegetable intake among adult residents (mean age, 54 y) of 15 subsidized housing complexes in Rhode Island (8 intervention sites and 7 control sites) in partnership with Rhode Island Housing. ^23,24 In contrast with Fresh to You, Live Well, Viva Bien featured a retrofitted car trailer with produce shelves so that participants could walk into the trailer to purchase produce. ²³ The trial was conducted in 3 types of public housing sites: housing for families, housing for adults aged >60, and housing for people with disabilities. In good weather, the markets were held outdoors at the family housing complexes using this trailer. At the housing complexes for older adults and people with disabilities, we continued to set up the markets indoors. The Live Well, Viva Bien intervention brought biweekly markets to each housing complex for 12 months and sold up to 70 local and nonlocal items, including staples, seasonal items, culturally desired produce, and exotic produce at discounted prices. ²³ The trial also included multiple educational activities at the markets, including 2 educational campaigns and monthly newsletters, DVDs, and taste-testing events at the markets. ²³

To evaluate the effectiveness of the markets on fruit and vegetable consumption, 1597 adult housing complex residents (intervention n = 837; control n = 760) were enrolled in the trial (73% women, 54% Hispanic). After 12 months of follow-up, residents in the intervention group significantly increased their fruit and vegetable intake compared with the control group (+0.44 cups vs –0.08 cups; P = .015). ²⁴ The findings suggest a dose–response relationship, as participants who attended “all” or “most” of the markets increased fruit and vegetable intake by 2.08 cups and 0.86 cups, respectively, compared with one-third cup or lower increases among participants with lower levels of market attendance (P = .046). ²³ Use of the DVDs, recipes, and taste-testing events was also associated with greater increases in fruit and vegetable intake, but the use of other educational components was not. ²³ Although the study was not originally powered to test differences between type of housing site (family vs older adults and people with disabilities), it found that fruit and vegetable consumption significantly increased at the housing complexes for older adults (0.48 cups/day, P = .01), and no significant change occurred in intake at family sites. ²⁴

Although the markets resulted in an increase in self-reported fruit and vegetable intake after 12 months, feedback from participants reported that market prices were a barrier for fruit and vegetable purchase and consumption, and overall sales at the markets were low. ²⁴ On the basis of these results, the researchers determined that program sustainability depended on addressing affordability by providing financial incentives with purchases and recommended that future iterations focus on market sites that had high sales and participation, particularly subsidized housing facilities for older adults.

Evolution of Food on the Move

Given the positive effect of the mobile produce markets on enhancing access to and consumption of fruit and vegetables, the research team sought out community partnerships to sustain the program beyond the life of research funding. When the research funding ended in 2016, the Rhode Island Public Health Institute (RIPHI) established Food on the Move as a scalable, sustainable, nonprofit social enterprise to continue the mobile market program as a community service. Food on the Move is a year-round mobile produce market that sells fruit and vegetables in communities with high rates of poverty in Rhode Island. The mission of Food on the Move is to make fresh, healthy produce accessible and affordable to everyone by bringing produce in a mobile market format to neighborhoods without grocery stores or produce markets. Food on the Move was informed by more than a decade of research.

RIPHI, a nonprofit with the mission of enhancing health equity in Rhode Island, is the appropriate home for Food on the Move because of its commitment to translational research and close partnership with both the Brown University School of Public Health and the Rhode Island Department of Health. To make the program feasible, RIPHI leadership recognized an immediate need to reduce operational costs from a multimillion-dollar research budget to a sustainable programmatic budget. Therefore, RIPHI developed a business plan that aimed to (1) identify efficiencies and dispense with low-performing sites to reduce programmatic costs; (2) build on findings of Fresh to You and Live Well, Viva Bien to make produce more affordable; (3) engage in continuing quality improvement activities to collect and evaluate market data to maximize effectiveness; and (4) diversify funding streams.

Enhancing Efficiencies

In Live Well, Viva Bien, we retrofitted a trailer with refrigeration and shelving to promote market mobility and decrease the labor costs associated with market setup and takedown. Despite this modification, however, many of the Live Well, Viva Bien markets still had to be held indoors during inclement weather and at sites for older adults or people with disabilities, which added time and labor costs to each market. Thus, one of the first grant applications written by RIPHI was to support the purchase of a customized refrigerated truck with shelving units that could be wheeled in and out of sites. This modification reduced market set-up time from approximately 1 hour to 20 minutes, allowed for more efficient staffing patterns for the program, and reduced overall program costs. The removable shelving units were an important innovation because older adults with limited mobility preferred the markets to be held indoors, regardless of weather. The team also procured funding to purchase more advanced point-of-sale software that allowed for better inventory-tracking capabilities. Moreover, the point-of-sale software informed RIPHI’s evaluation measures for identifying successful market sites to keep in operation based on total sales and percentage of transactions with SNAP benefits.

Reducing Fruit and Vegetable Costs

To capitalize on the lessons learned from Fresh to You and Live Well, Viva Bien, RIPHI applied for a US Department of Agriculture Food Insecurity Nutrition Incentive (FINI) pilot grant in 2015. FINI grants support community-based projects that aim to increase the purchase of fruit and vegetables among SNAP participants by providing incentives at the point of purchase. ²⁵ This grant allowed Food on the Move to offer a dollar-for-dollar match on produce purchased with SNAP benefits, addressing customers’ needs for lower-cost produce. Initially, Food on the Move issued the incentive to SNAP customers in the form of a matching gift card. In 2016, $28 664 in incentives was distributed to SNAP customers at Food on the Move as gift cards (Table). Overall, 13% of gift cards were never redeemed, meaning that customers were not receiving the full value of the incentive. With a subsequent FINI grant, Food on the Move tested a second incentive structure, in which it offered a 50% discount at the point of sale for purchases made with SNAP benefits, providing the same level of incentive through a different format. In this model, SNAP customers received the incentive immediately at the point of sale. The discount eliminated time and financial costs associated with issuing gift cards, which cost about $1 each and slowed down checkout times. This incentive structure was also well received by customers, because redemption was immediate and did not require customers to keep track of gift cards for return trips. After this transition in January 2018, the distribution of SNAP incentives increased 66% from 2017-2018, resulting in $50 345 in incentives in 2018 (Table). Similarly, the use of SNAP benefits at the market increased, representing 50% of all transactions in 2018.

Table.

Summary data of Food on the Move, ^a by year, Rhode Island, 2016-2018

Variable	2016	2017	2018
No. of sites served	34	28	18
No. of market occurrences	316	321	335
Average no. of markets per site	9.4	11.5	18.6
No. of unique transactions per year	8520	9236	10 940
No. of SNAP transactions per year	3231	3728	5482
% Transactions with SNAP	38	40	50
Total sales (including incentives), $	98 855	114 875	162 328
SNAP incentives, $	28 664	30 307	50 345
Average amount of purchase, $	11.60	12.44	14.80

Abbreviation: SNAP, Supplemental Nutrition Assistance Program.

^aFood on the Move is a year-round mobile produce market that sells fruit and vegetables in communities with high rates of poverty in Rhode Island. ²²

Evaluation of Market Data to Maximize Effectiveness

In its initial business plan, Food on the Move served worksites and community sites to facilitate a model whereby purchases at the higher-income worksites would partially subsidize purchases in lower-income community sites. Evaluation of 2016 market point-of-sale data showed that Food on the Move held 316 markets at 34 unique sites and averaged 9.4 markets per site per year (Table). In total, the markets sold $98 855 in produce, and the average transaction amount was $11.60. Given that fruit and vegetables are perishable and do not last an entire month, these data suggested that the potential effect of Food on the Move was being limited by serving 34 sites with 1 mobile market. Therefore, Food on the Move phased out most worksites in 2017 and focused on serving low-income community sites more regularly by hosting weekly markets. In 2018, Food on the Move served 18 community sites, held 335 markets, and doubled the average annual number of markets held per site. These changes were associated with increases in market sales of more than $65 000 (from $98 855 in 2016 to $162 328 in 2018), and the average transaction amount increased to $14.80. As a result of this change in weekly format and incentive structure, Food on the Move markets were associated with an increased effect on fruit and vegetable purchases in communities with limited access to produce. ²⁶ To estimate the impact of these sales on potential fruit and vegetable intake, we converted sales data, expressed as pounds of food sold, to estimated servings of fruit and vegetables using the US Food and Drug Administration Guide for Human Consumption: 140 g per serving of fruit and 85 g per serving of vegetables. ²⁷ Point-of-sale data showed that 594 998 servings of fresh fruit and vegetables were sold at Food on the Move in 2018. Sixty-three percent of servings sold were vegetables, 31% were fruit, 5% were potatoes, and 1% were dry beans. In all, 1776 servings of fruit and vegetables were sold at each market, which translated to an additional 33 055 servings of fruit and vegetables sold in 18 low-income communities in Rhode Island in 2018.

Diversifying Funding Streams to Support Food on the Move

Although Food on the Move reduced overhead and recognized operational efficiencies, the program still relies on grant revenue for 85% of its overall $425 000 in annual operating costs, including its evaluation staff. FINI grants have been essential to Food on the Move selling produce at affordable prices. Staff, evaluation, and capital expenses have been supported by chronic disease prevention grants from the Centers for Disease Control and Prevention and local and national foundations. Since 2015, Food on the Move has received funding from the Champlin Foundation, the Rhode Island Foundation, AARP Foundation, and Blue Cross Blue Shield of Rhode Island. Philanthropic support is essential to sustaining Food on the Move, particularly given RIPHI’s commitment to enhancing health equity. Although Food on the Move’s model is a social enterprise, its commitment to translational research requires additional funding support. Other nonprofit mobile produce markets operating in food deserts or low-income neighborhoods also have relied heavily on grant funding. ¹⁹

Lessons Learned

With each federal funding cycle, the National Institutes of Health spends billions of dollars on research testing best practices to prevent chronic diseases and address health disparities. Peer-reviewed journals regularly publish on the success of this work; yet, the rates of chronic disease continue to rise, and health disparities continue to widen. More than 34 million people in the United States (10.5%) have diabetes, ²⁸ with higher rates among Hispanic and non-Hispanic Black Americans and people from low-income households than among non-Hispanic White Americans and people from high-income households. ^{9 -11} This disparity is especially concerning because the overall prevalence of diabetes has increased in the United States during the past 2 decades. ²⁶ For sustained change in communities, researchers and community partners need examples of how to translate the results of research trials into public health practice. After 2 research-funded studies demonstrated the effect of mobile markets in enhancing access to and consumption of fruit and vegetables, RIPHI adopted and scaled the program across the state. We scaled Food on the Move by (1) identifying efficiencies and dispensing with poor-performing markets to reduce programmatic costs, (2) engaging in ongoing quality improvement, (3) implementing an innovative SNAP incentive program, and (4) diversifying funding streams. Although Food on the Move still relies heavily on philanthropic support for maximal effect, it nevertheless offers important lessons about translating research into sustainable public health programs.