Price discounts significantly enhance fruit and vegetable purchases when combined with nutrition education: A randomized controlled supermarket trial

摘要

Background: Reducing fruit and vegetable (FV) prices is a frequently considered policy to improve dietary habits in the context of health promotion. However, evidence on the effectiveness of this intervention is limited. Objective: The objective was to examine the effects of a 50 price discount on FVs or nutrition education or a combination of both on supermarket purchases. Design: A 6-mo randomized controlled trial within Dutch supermarkets was conducted. Regular supermarket shoppers were randomly assigned to 1 of 4 conditions: 50 price discounts on FVs, nutrition education, 50 price discounts plus nutrition education, or no intervention. A total of 199 participants provided baseline data; 151 (76) were included in the final analysis. FV purchases were measured by using supermarket register receipts at baseline, at 1 mo after the start of the intervention, at 3 mo, at 6 mo (end of the intervention period), and 3 mo after the intervention ended (9 mo). Results: Adjusted multilevel models showed significantly higher FV purchases (per household/2 wk) as a result of the price discount (+3.9 kg; 95 CI: 1.5, 6.3 kg) and the discount plus education intervention (+5.6 kg; 95 CI: 3.2, 7.9 kg) at 6 mo compared with control. Moreover, the percentage of participants who consumed recommended amounts of FVs (≥400 g/d) increased from 42.5 at baseline to 61.3 at 6 mo in both discount groups (P = 0.03). Education alone had no significant effect. Conclusions: Discounting FVs is a promising intervention strategy because it resulted in substantially higher FV purchases, and no adverse effects were observed. Therefore, pricing strategies form an important focus for future interventions or policy. However, the long-term effects and the ultimate health outcomes require further investigation. This trial was registered at the ISRCTN Trial Register as number ISRCTN56596945 and at the Dutch Trial Register (http://www.trialregister.nl/trialreg/index.asp) as number NL22568.029.08.