Objective: Fiscal policies may form a solution in improving dietary intake. This study aimed to examine the effectiveness of varying taxing and subsiding schemes to stimulate healthier food purchases. Methods: A randomized controlled trial with three levels of price reduction on healthy foods (no; 25%; 50%) × three levels of price increase on unhealthy foods (5%; 10%; 25%) factorial design was used. 150 participants were randomized into one of nine conditions and were asked to purchase groceries at a web-based supermarket. Data were collected in the Netherlands in January-February 2010 and analyzed using analysis of covariance. Results: Subjects receiving 50% discount purchased significantly more healthy foods than subjects receiving no (mean difference = 6.62 items, p < 0.01) or 25% discount (mean difference = 4.87 items, p < 0.05). Moreover, these subjects purchased more vegetables (mean difference = 821 g; p < 0.05 compared to no discount). However, participants with the highest discount also purchased significantly more calories. No significant effects of the price increases on unhealthy foods were found. Conclusion: Price decreases are effective in stimulating healthy food purchases, but the proportion of healthy foods remains unaffected. Price increases up to 25% on unhealthier products do not significantly affect food purchases. Future studies are important to validate these results in real supermarkets and across different countries. © 2012 Elsevier Inc.
Waterlander, W. E., Steenhuis, I. H. M., de Boer, M. R., Schuit, A. J., & Seidell, J. C. (2012). Introducing taxes, subsidies or both: the effects of various food pricing strategies in a web-based supermarket randomized trial. Preventive Medicine, 54(5), 323-330. https://doi.org/10.1016/j.ypmed.2012.02.009