The impact of financial incentives and restrictions on cyclical food expenditures among low-income households receiving nutrition assistance: a randomized controlled trial

BACKGROUND: The Supplemental Nutrition Assistance Program (SNAP) is the largest anti-hunger program in the United States. Two proposed interventions to encourage healthier food expenditures among SNAP participants have generated significant debate: financial incentives for fruits and vegetables, and restrictions on foods high in added sugar. To date, however, no study has assessed the impact of these interventions on the benefit cycle, a pattern of rapid depletion of SNAP benefits that has been linked to worsening nutrition and health outcomes over the benefit month. METHODS: Low-income households not currently enrolled in SNAP (n = 249) received benefits every 4 weeks for 12 weeks on a study-specific benefit card. Households were randomized to one of four study arms: 1) incentive (30% incentive for fruits and vegetables purchased with study benefits), 2) restriction (not allowed to buy sugar-sweetened beverages, sweet baked goods, or candy using study benefits), 3) incentive plus restriction, or 4) control (no incentive or restriction). Weekly household food expenditures were evaluated using generalized estimating equations. RESULTS: Compared to the control group, financial incentives increased fruit and vegetable purchases, but only in the first 2 weeks after benefit disbursement. Restrictions decreased expenditures on foods high in added sugar throughout the benefit month, but the magnitude of the impact decreased as the month progressed. Notably, restrictions mitigated cyclical expenditures. CONCLUSIONS: Policies to improve nutrition outcomes among SNAP participants should consider including targeted interventions in the second half of the month to address the benefit cycle and attendant nutrition outcomes. TRIAL REGISTRATION: ClinicalTrial.gov, NCT02643576. Retrospectively registered December 22, 2014. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12966-021-01223-7.