Full-Service Mobile Food Markets and Dietary Quality in Low-Income Housing Communities: A Randomized Clinical Trial.

Abstract

Full-service mobile markets, also known as grocery stores on wheels, may improve diet-related outcomes by bringing low-cost, nutritious food to individuals experiencing low incomes and low food access. To determine the impact of the full-service Twin Cities Mobile Market on dietary outcomes in low-income communities. This cluster randomized clinical trial was conducted over 3 waves (January 2022 to October 2025) across 12 public or private subsidized housing sites in the Minneapolis-St. Paul, Minnesota, area. Participants were screened for interest in the mobile market. Follow-up assessments began after 6 months of market service. Analyses were finalized September 2026. Sites were randomized to weekly market service or waiting list control groups. Primary outcome: diet quality (Healthy Eating Index-2020 via 24-hour recalls). A priori secondary outcomes: dietary intake (fruit and vegetable, energy, sodium, and percentage of calories from added sugar), food security (18-item US Department of Agriculture Food Security Screening Module), and fruit and vegetable servings procured for the home (validated tracking tool). Adjusted intention-to-treat (ITT) generalized estimating equations were used to assess outcome differences between treatment groups. Among 262 adults who enrolled in the mobile market study, 242 participants (mean [SD] age, 66.5 [11.5] years; 156 women [64.5%]) across 12 sites completed baseline assessments and were randomized to mobile market service or waiting list control groups. There were 137 individuals (56.6%) who received Supplemental Nutrition Assistance Program (SNAP) benefits. Sites had a mean (SD) of 18.2 (4.4) weekly transactions (mean of 110 of 1071 households [10.3%]). Of 109 intervention site participants, 47 individuals (43.1%) shopped at the mobile market 1 or more times in implementation months 5 to 6, while 90 of 94 individuals who reported ever using the market (95.7%) reported that they would recommend the market service. Participant retention was 218 of 242 participants (90.0%). In ITT models, the primary outcome of diet quality (adjusted mean difference, 1.25 [95% CI, -1.60 to 4.10]) among 215 participants and 6 of 7 secondary outcomes (fruit and vegetable, energy, and added sugar intake; food security and food security improvement; fruit and vegetable procurement) were not significantly different between groups. Intervention site participants consumed an adjusted mean difference of 397 mg (95% CI, -636 to -158 mg) less sodium daily compared with participants in the waiting list control group. Main findings were consistent across 4 sensitivity and supplemental analyses, except the per-protocol sensitivity analysis, which found that participants in the intervention group consumed an adjusted mean difference of 2.35% (95% CI, 0.66%-4.04%) more calories from added sugar compared with the control group. In this study, satisfaction with the mobile market was high, but the mobile market did not improve diet quality or most outcomes examined. The mobile market was associated with a meaningful sodium reduction that could improve population-level health. ClinicalTrials.gov Identifier: NCT05672186.