Buying health: assessing the impact of a consumer-side vegetable subsidy on purchasing, consumption and waste

Abstract

Objective: To measure the impact of a reimbursement-based consumer subsidy on vegetable expenditures, consumption and waste. Design: Two-arm randomized controlled trial; two-week baseline observation period, three-week intervention period. Participants' vegetable expenditures, consumption and waste were monitored using receipts collection and through an FFQ. During the intervention period, the treatment group received reimbursement of up to 50 US dollars ($) for purchased vegetables. Setting: Participants were solicited from Palo Alto, CA, USA using materials advertising a 'consumer behavior study' and a small participation incentive. To prevent selection bias, solicitation materials did not describe the specific behaviour being evaluated. Subjects: One hundred and fifty potential participants responded to the solicitations and 144 participants enrolled in the study; 138 participants completed all five weekly surveys. Results: Accounting for the control group (n 69) and the two-week baseline period, the intervention significantly impacted the treatment group's (n 69) vegetable expenditures (+ $8·16 (SD 2·67)/week, P < 0·01), but not vegetable consumption ( +1·3 (SD 1·2) servings/week, P = 0·28) or waste (−0·23 (SD 1·2) servings/week, P = 0·60). Conclusions: The consumer subsidy significantly increased participants' vegetable expenditures, but not consumption or waste, suggesting that this type of subsidy might not have the effects anticipated. Reimbursement-based consumer subsidies may therefore not be as useful a policy tool for impacting vegetable consumption as earlier studies have suggested. Moreover, moderation analysis revealed that the subsidy's effect on participants' vegetable expenditures was significant only in men. Additional research should seek to determine how far reaching genderspecific effects are in this context. Further research should also examine the effect of a similar consumer subsidy on high-risk populations and explore to what extent increases in participants' expenditures are due to the purchase of more expensive vegetables, purchasing of vegetables during the study period that were consumed outside the study period, or a shift from restaurant vegetable consumption to grocery vegetable consumption.

The impact of the consumer and neighbourhood food environment on dietary intake and obesity-related outcomes: A systematic review of causal impact studies

“…The effect of in-kind incentives on children was investigated by two studies reporting toy premiums significantly increased children’ purchases (tracked by scan cards) of healthier and low-calorie meals in fast-food restaurants, and FV snacks in local zoos( Hobin et al, 2012 ; Karpyn et al, 2017 ). Fifteen studies focused on the effect of financial incentives on dietary intake ( Jilcott Pitts et al, 2018a ; Geliebter et al, 2013 ; Waterlander et al, 2013a ; Harnack et al, 2016 ; Ball et al, 2015 ; Kral et al, 2016 ; Bernales-Korins et al, 2017 ; Smith-Drelich, 2016 ; Franckle et al, 2018 ), purchases ( Waterlander et al, 2013a , 2013b ; Ball et al, 2015 ; Kral et al, 2016 ; Bernales-Korins et al, 2017 ; Smith-Drelich, 2016 ; Franckle et al, 2018 ; Blakely et al, 2011 ; Guan et al, 2018 ; Banerjee and Nayak, 2018 ; Polacsek et al, 2018 ; Gopalan et al, 2019 ), and BMI ( Jilcott Pitts et al, 2018a ; Geliebter et al, 2013 ; Waterlander et al, 2013a ; Harnack et al, 2016 ; Kral et al, 2016 ), among adult samples. The type of financial incentives varied, including different levels of price reductions ( Jilcott Pitts et al, 2018a ; Geliebter et al, 2013 ; Waterlander et al, 2013a , 2013b ; Harnack et al, 2016 ; Ball et al, 2015 ; Bernales-Korins et al, 2017 ; Blakely et al, 2011 ; Polacsek et al, 2018 ), coupons for targeted products ( Franckle et al, 2018 ; Guan et al, 2018 ; Banerjee and Nayak, 2018 ), and cash back payments (reimbursements) ( Kral et al, 2016 ; Smith-Drelich, 2016 ; Gopalan et al, 2019 ) based on purchasing behaviour.…”

“…Mixed results were found for the impact of cash back payments on healthy food purchases (measured by checking receipts) as one study incentivizing vegetable purchases in supermarkets found positive results ( Smith-Drelich, 2016 ), while two studies that incentivized a variety of healthy items reported null ( Kral et al, 2016 ; Gopalan et al, 2019 ). These studies are RCTs with low risk of bias score.…”

“…For the consumer food environment our results confirm and complement previous findings on financial incentives by suggesting that price discounts and coupons could significantly increase the intake and purchases of healthy foods among children and adults from different socioeconomic backgrounds ( Cameron et al, 2016 ; An, 2013 ). The exception is for cash back payments which null effects on outcomes could be due to research design limitations such as temporal separation between the shopping and the cash back payments ( Kral et al, 2016 ; Smith-Drelich, 2016 ; Gopalan et al, 2019 ). The added effort of going to the research centre, showing the receipts, and waiting for payment might diminish the effect of the financial incentive, especially for the targeted samples that were high income ( Kral et al, 2016 ; Smith-Drelich, 2016 ; Gopalan et al, 2019 ).…”

Vegetables, Herbs and Spices: The Importance of Family and Tasting

“…While past research has explored strategies such as serving more of a vegetable [39], serving a wider variety of vegetables [40] and offering a vegetable subsidy (price reduction) to make them more affordable [41] to increase vegetable intake, focus group findings here suggest that tasting or sampling opportunities as well as preparation suggestions and demonstrations may be effective means to introduce consumers to new vegetables. Additional research is needed to better explain the interaction of favorite vegetables and frequently eaten vegetables.…”

Retail Nutrition Programs and Outcomes: An Evidence Analysis Center Scoping Review

“…Sixty-six studies looked at the impact of interventions on store sales and ROI for the food retailer. Fifty studies reported an increase in store sales after the intervention, with the greatest outcomes produced by coupon/vouchers (n ¼ 11), 68-71,89,98,103,106,107,109,124 signage, displays and nutrition labels (n ¼ 8), 149,151,153,158,159,164,165,167 rebate programs (n ¼ 4), 88,90,93,130 and a combination of incentive programs with pathto-purchase marketing (n ¼ 3). 182,199,200 Nutritional Quality of Shopping Purchases.…”