TY - JOUR
T1 - Shifting toward a healthier dietary pattern through nudging and pricing strategies
T2 - A secondary analysis of a randomized virtual supermarket experiment
AU - Stuber, Josine M.
AU - Hoenink, Jody C.
AU - Beulens, Joline W. J.
AU - Mackenbach, Joreintje D.
AU - Lakerveld, Jeroen
N1 - Funding Information: This study was conducted as part of the doctoral thesis of JMS. Her work, as well as that of JCH and JDM, is supported through the Supreme Nudge program funded by the Dutch Heart Foundation and the Netherlands Organization for Health Research and Development (CVON2016-04). JDM is further funded by an NWO VENI grant on ?Making the Healthy Choice Easier?Role of the Local Food Environment? (grant 451-17-032). The funders have no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, nor have they authority on the decision to submit the manuscript for publication. Publisher Copyright: © The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/8/1
Y1 - 2021/8/1
N2 - Background: Nudging and salient pricing are promising strategies to promote healthy food purchases, but it is possible their effects differ across food groups. Objective: To investigate in which food groups nudging and/or pricing strategies most effectively changed product purchases and resulted in within-food groups substitutions or spillover effects. Methods: In total, 318 participants successfully completed a web-based virtual supermarket experiment in the Netherlands. We conducted a secondary analysis of a mixed randomized experiment consisting of 5 conditions (within subject) and 3 arms (between subject) to investigate the single and combined effects of nudging (e.g., making healthy products salient), taxes (25% price increase), and/or subsidies (25% price decrease) across food groups (fruit and vegetables, grains, dairy, protein products, fats, beverages, snacks, and other foods). Generalized linear mixed models were used to estimate the incidence rate ratios and 95% CIs for changes in the number of products purchased. Results: Compared with the control condition, the combination of subsidies on healthy products and taxes on unhealthy products in the nudging and price salience condition was overall the most effective, as the number of healthy purchases from fruit and vegetables increased by 9% [incidence rate ratio (IRR) = 1.09; 95% CI: 1.02, 1.18], grains by 16% (IRR = 1.16; 95% CI: 1.05, 1.28), and dairy by 58% (IRR = 1.58; 95% CI: 1.31, 1.89), whereas the protein and beverage purchases did not significantly change. Regarding unhealthy purchases, grains decreased by 39% (IRR = 0.72; 95% CI: 0.63, 0.82) and dairy by 30% (IRR = 0.77; 95% CI: 0.68, 0.87), whereas beverage and snack purchases did not significantly change. The groups of grains and dairy showed within-food group substitution patterns toward healthier products. Beneficial spillover effects to minimally targeted food groups were seen for unhealthy proteins (IRR = 0.81; 95% CI: 0.73, 0.91). Conclusions: Nudging and salient pricing strategies have a differential effect on purchases of a variety of food groups. The largest effects were found for dairy and grains, which may therefore be the most promising food groups to target in order to achieve healthier purchases. The randomized trial on which the current secondary analyses were based is registered in the Dutch trial registry (NTR7293; www.trialregister.nl).
AB - Background: Nudging and salient pricing are promising strategies to promote healthy food purchases, but it is possible their effects differ across food groups. Objective: To investigate in which food groups nudging and/or pricing strategies most effectively changed product purchases and resulted in within-food groups substitutions or spillover effects. Methods: In total, 318 participants successfully completed a web-based virtual supermarket experiment in the Netherlands. We conducted a secondary analysis of a mixed randomized experiment consisting of 5 conditions (within subject) and 3 arms (between subject) to investigate the single and combined effects of nudging (e.g., making healthy products salient), taxes (25% price increase), and/or subsidies (25% price decrease) across food groups (fruit and vegetables, grains, dairy, protein products, fats, beverages, snacks, and other foods). Generalized linear mixed models were used to estimate the incidence rate ratios and 95% CIs for changes in the number of products purchased. Results: Compared with the control condition, the combination of subsidies on healthy products and taxes on unhealthy products in the nudging and price salience condition was overall the most effective, as the number of healthy purchases from fruit and vegetables increased by 9% [incidence rate ratio (IRR) = 1.09; 95% CI: 1.02, 1.18], grains by 16% (IRR = 1.16; 95% CI: 1.05, 1.28), and dairy by 58% (IRR = 1.58; 95% CI: 1.31, 1.89), whereas the protein and beverage purchases did not significantly change. Regarding unhealthy purchases, grains decreased by 39% (IRR = 0.72; 95% CI: 0.63, 0.82) and dairy by 30% (IRR = 0.77; 95% CI: 0.68, 0.87), whereas beverage and snack purchases did not significantly change. The groups of grains and dairy showed within-food group substitution patterns toward healthier products. Beneficial spillover effects to minimally targeted food groups were seen for unhealthy proteins (IRR = 0.81; 95% CI: 0.73, 0.91). Conclusions: Nudging and salient pricing strategies have a differential effect on purchases of a variety of food groups. The largest effects were found for dairy and grains, which may therefore be the most promising food groups to target in order to achieve healthier purchases. The randomized trial on which the current secondary analyses were based is registered in the Dutch trial registry (NTR7293; www.trialregister.nl).
KW - choice architecture
KW - food policy
KW - grocery store intervention
KW - price change
KW - public health
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85104652021&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/33829225
UR - http://www.scopus.com/inward/record.url?scp=85104652021&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/ajcn/nqab057
DO - https://doi.org/10.1093/ajcn/nqab057
M3 - Article
C2 - 33829225
SN - 0002-9165
VL - 114
SP - 628
EP - 637
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
IS - 2
ER -