Mobile food markets have been proposed as a strategy for mitigating health disparities related to poor nutrition and diet/weight-related health conditions because they bring low-cost, healthy food directly to underserved populations. Full-service mobile markets may improve multiple aspects of the diet by providing foods to meet all dietary needs through a convenient one-stop shop. The full-service mobile market to be tested (Twin Cities Mobile Market) sells nutritious and staple foods from a bus that regularly visits low-income neighborhoods. Foods are sold at prices ~10% below those of grocery stores. SNAP/EBT is accepted, and a state-funded fruit/vegetable incentive program (Market Bucks) is available to shoppers. Working in partnership with our community team members, we will enroll 12 total sites and recruit 22 participants per site (N=264). We will collect baseline data and randomize sites to either receive the full-service mobile market intervention or serve as the waitlist control. We will then implement the full-service mobile market at intervention sites, follow participants for 6 months, and collect follow-up data. After follow-up data collection, waitlist control sites will receive the full-service mobile market intervention. Diet quality will be assessed through dietary recall interviews, food insecurity will be assessed by survey, and fruit and vegetable purchases will be measured by collecting one month of food purchase tracking forms at baseline and follow-up data collection. Analyses will determine whether the full-service mobile market changes diet quality, food security, and food purchasing outcomes.

Inclusion Criteria:

Community sites (e.g., public housing hi-rise, low-income senior living residence) must meet the following criteria:

• locale for low-income populations that experience difficulty in accessing healthy, affordable foods (e.g., public housing residences; low-income senior housing) or a community center in a low-income, low-food access (0.5 mile) census tract;
• willingness to be randomized to the intervention or waitlist control;
• located over 0.5 miles apart from other trial sites;
• willingness to allow for recruitment and data collection to occur in onsite community rooms

Participants must meet the following criteria:

• being aged 18 years or older;
• identifying as the primary food shopper in their household;
• being able to speak English or ASL;
• living within a half mile of the community site location; and
• reporting to be likely or somewhat likely to shop at the market in response to: "how likely would you be to shop regularly at the Twin Cities Mobile Market if it came to your neighborhood each week (response options: likely to unlikely).
• willing and able to participate in all study data collection activities

Exclusion Criteria:

• planning to move in the next 12 months
• currently shopping at the mobile market
• not having a phone number or mailing address
• presence of a condition or abnormality that would prohibit participation in the study or the quality of the data

The study protocol, statistical analysis plan, and consent form are available on the trial's clinicaltrials.gov registry (NCT05672186). Quarto (R Markdown) documents will describe and implement all data extraction, cleaning, and analysis steps, and the resulting files will be made publicly available alongside all publications resulting from this study. To support the reproducibility and replication of our findings, upon completion of the trial, we will share anonymized quantitative participant data used in publications of outcomes with the community partner and researchers. Proposals to access the data should be directed to horn0199@umn.edu.

Upon completion of the trial

Proposals to access the data should be directed to horn0199@umn.edu.

Following site enrollment, sites will be randomized by wave to receive the full-service market intervention or serve as a waitlist control by the study statistician, who will be blinded to study site names. After randomization, the study statistician will be unblinded to site names by being given the key that matches sites with their assigned numbers. The study statistician will use this key to inform the mobile market co-investigator of site allocation to allow time for the mobile market to plan for market routes and schedules while baseline data collection is ongoing. Participants, site locations, the PI, university non-statistician trial investigators, and research staff will be blinded to site randomization results until baseline data collection is complete. Only the project manager and study statistician will be aware of the key (the link between the site names and the assigned site numbers linked to the data to be used in analysis) until analysis is complete.