Voucher for Healthy Foods and Diabetes Control: A Randomized Clinical Trial

Introduction

Diabetes management depends heavily on healthy nutrition, but access to nutritious foods varies widely, especially among populations facing food insecurity. While programs offering healthy food vouchers exist in select regions, their direct impact on glycemic control in people with diabetes has remained unclear. This randomized clinical trial aimed to assess whether monthly grocery vouchers designed to improve access to healthy foods could influence diabetes control measured by hemoglobin A1c (HbA1c) levels in food-insecure adults with diabetes.

Study Design and Participants

The trial was conducted across seven sites in Toronto, Canada, from March 2023 through April 2025. Food-insecure patients with diagnosed diabetes and baseline HbA1c values between 6.0% and 11% were recruited and randomized into two groups: one received monthly vouchers for healthy groceries, and the other continued usual access to food without added financial assistance.

Among 1,061 patients approached, 390 enrolled with a balanced demographic profile including 49% men and 51% women, and diverse racial/ethnic representation (approximately 21% Black, 24% South Asian, and 27% White participants). Randomization assigned 194 participants to the voucher intervention and 196 to the control group.

Intervention Details

Participants in the intervention arm received monthly vouchers valued at $65 CAD (increased to $85 CAD for households with six or more members), redeemable for healthy foods over six months. The voucher was intended to facilitate increased purchase of fruits, vegetables, and other nutritious foods despite economic or environmental barriers.

Primary and Secondary Outcomes

The primary outcome measured was change in HbA1c levels from baseline to 6 months, which reflects average blood glucose control over the prior three months. Secondary outcomes included biochemical markers of diet quality (levels of serum β-carotene and ascorbic acid), self-reported frequency of fruit and vegetable consumption, financial security status, food security, and general self-rated health.

Results

The primary analysis showed a nonsignificant adjusted mean difference in HbA1c change between the voucher and control groups of -0.10% (95% CI, -0.33 to 0.12; P = .35), indicating that provision of the vouchers did not meaningfully reduce average blood sugar levels within six months.

However, participants receiving vouchers reported notably higher frequency of vegetable consumption twice or more per day (44.7% vs 21.5%) and fruit consumption (42.6% vs 22.7%) compared with controls. Food insecurity was significantly reduced (risk difference -0.10; 95% CI, -0.18 to -0.02), and participants reported improvements in general health status (odds ratio, 1.6; 95% CI, 1.1-2.3). There was no significant effect on financial insecurity or on serum β-carotene and ascorbic acid levels.

Discussion

While the monthly food voucher program improved self-reported intake of fruits and vegetables and helped reduce food insecurity, it did not translate to improved glycemic control or biochemical markers of diet quality over a 6-month period. Several factors may explain this. First, the baseline HbA1c levels and duration may require longer follow-up to see meaningful change. Second, self-reported dietary improvements may reflect increased consumption but not necessarily sufficient or consistent quality changes to alter glycemic measures. Third, the dose and duration of food voucher assistance may need adjustment.

These findings highlight the complexities in addressing diabetes through nutrition interventions in real-world settings, especially among populations facing socioeconomic challenges. Although improving food security and diet diversity is critical, additional strategies—such as nutrition education, diabetes self-management support, and broader socioeconomic interventions—are likely needed to achieve clinically meaningful glycemic improvements.

Conclusions

This randomized clinical trial demonstrated that monthly grocery vouchers facilitating access to healthy foods increased self-reported fruit and vegetable consumption and reduced food insecurity but did not significantly improve diabetes control as measured by HbA1c over six months. Future policies aiming to improve diabetes outcomes should consider multifaceted approaches that integrate financial assistance with education and medical support for people with diabetes experiencing food insecurity.

Trial Registration

ClinicalTrials.gov Identifier: NCT05776420.

References

Persaud N, Ul Haq MZ, Buadu A, Sabir A, Sinha L, Thorpe KE, Xu K, Hwang SW, Pinto AD, Gucciardi E. Voucher for Healthy Foods and Diabetes Control: A Randomized Clinical Trial. JAMA Intern Med. 2025 Dec 1;185(12):1434-1441. doi: 10.1001/jamainternmed.2025.5420. PMID: 41114992; PMCID: PMC12538504.