Impact of Three Nutrition Incentive Levels on Fruit and Vegetable Purchasing, Consumption, and Food Security: A 12-month Randomized Control Trial with 6-month Follow-Up

Background : Little is known about the impact of different nutrition incentive (NI) levels on fruit and vegetable (F&V) consumption and food security. Our goal was to compare the impact of three NI levels ($10/month, $20/month, and $40/month) on F&V purchasing, consumption, and food security. Methods : A three-arm randomized controlled trial (¡Más Fresco! More Fresh) involving six large retail grocery stores in Los Angeles, Orange, and San Diego counties in southern California was conducted between 2017-2020. SNAP participants, age ≥18 years who lived within 5-miles of stores, self-referred. Participants earned $1 in F&V incentives for every $1 of fresh F&V bought using SNAP benefits. Incentives were capped at $10, $20, or $40/month for 12 months; participants were randomized using a 1:1:1 ratio. Monthly NI redemptions, total F&V spending, total grocery spending, self-reported F&V consumption, and food security were captured via individual-level point-of-sale data and online surveys at baseline, 6 months, 12 months, and 6-month follow-up after incentives ended (month 18). Mixed effects regression models were conducted among 1409 participants who used the program for ≥3 months. Results : Most participants were female (90%) and Latino (92%); 75% reported low/very low food security. The $40 group had the highest monthly mean redemptions ($10 group, $8.66; $20 group, $12.62; $40 group, $16.69, p<0.001) and spent an average of $36.11 on F&V per month (vs. $23.46 and $29.56 in the $10 and $20 groups, respectively, p<0.001). However, they earned proportionally less of their monthly allowable incentives ($10 group: 74.5%, $20 group: 58.5%, $40 group: 40.8%, p<0.001). The $40 group reported 0.18 cups greater F&V consumption at 12 months compared to the $10 group (p<0.05). The adjusted odds of low/very low food security only decreased in the $40 group at 12 months (aOR=0.44, 95%CI 0.29-0.66). F&V intake and food security improvements were no longer significant at 6-month follow-up, after incentives ended. Conclusion and Relevance : The $40 group had significantly greater F&V consumption and improved food security. However, they did not redeem their full incentive, and program effects waned after incentives stopped. Additional efforts are needed to sustain these programs and increase redemption of available incentives. Trial Registration : http://clinicaltrials.gov. Identifier: NCT02976389. Registration date: November 21, 2016