Introducing taxes, subsidies or both: the effects of various food pricing strategies in a web-based supermarket randomized trial

Prev Med. 2012 May;54(5):323-30. doi: 10.1016/j.ypmed.2012.02.009. Epub 2012 Feb 23.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Commerce / statistics & numerical data
  • Commerce / trends
  • Costs and Cost Analysis
  • Factor Analysis, Statistical
  • Female
  • Financing, Government*
  • Food Preferences / psychology*
  • Food Supply / economics*
  • Food Supply / legislation & jurisprudence
  • Health Behavior*
  • Health Policy
  • Health Promotion / methods
  • Humans
  • Internet
  • Male
  • Middle Aged
  • Netherlands
  • Nutrition Policy
  • Taxes*
  • Vegetables