Less meat in the shopping basket. The effect on meat purchases of higher prices, an information nudge and the combination: a randomised controlled trial

The effects of nudging and pricing strategies on the availability and purchases of ultra-processed foods: A secondary analysis of the Supreme Nudge trial

Regular consumption of ultra-processed foods (UPF) is a risk factor for morbidity and mortality. UPF are widely available in supermarkets. Nudging and pricing strategies are promising strategies to promote healthier supermarket purchases and may reduce UPF purchases. We investigated whether supermarket nudging and pricing strategies targeting healthy foods, but not specifically discouraging UPF, would change UPF availability, price, promotion and placement (UPF-APPP) in supermarkets and customer UPF purchases. We used data from the Supreme Nudge parallel cluster-randomized controlled trial, testing the effect of a combined nudging and pricing intervention promoting healthy products. The Dutch Consumer Food Environment Score (D-CFES) was used to audit 12 participating supermarkets in terms of UPF-APPP. We used customer loyalty card data of the first twelve intervention weeks from 321 participants to calculate the proportion of UPF purchases. Descriptive statistics were used to assess differences in D-CFES between supermarkets. Mixed model analyses were used to assess the association between the D-CFES and UPF purchases and the effect of the intervention on UPF purchases. No difference in the D-CFES between intervention and control supermarkets were found. No statistically significant association between the D-CFES and UPF purchases (β = -0.00, 95%CI: -0.02, 0.01) and no significant effect of the intervention on UPF purchases (β = 0.02, 95%CI: -0.07, 0.12) was observed. Given the significant proportion of unhealthy and UPF products in Dutch supermarkets, nudging and pricing strategies aimed at promoting healthy food purchases are not sufficient for reducing UPF-APPP nor purchases, and nationwide regulation may be needed.Trial registration number: Dutch Trial Register ID NL7064, May 30, 2018, https://trialsearch.who.int/Trial2.aspx?TrialID=NTR7302.

The effects of health-related food taxes on the environmental impact of consumer food purchases: secondary analysis of data from a randomised controlled trial in a virtual supermarket

OBJECTIVE

To measure the effects of health-related food taxes on the environmental impact of consumer food purchases in a virtual supermarket.

DESIGN

This is a secondary analysis of data from a randomised controlled trial in which participants were randomly assigned to a control condition with regular food prices (n 152), an experimental condition with a sugar-sweetened beverage (SSB) tax (n 131) or an experimental condition with a nutrient profiling tax based on Nutri-Score (n 112). Participants were instructed to undertake their typical weekly grocery shopping for their households. Primary outcome measures were three environmental impact indicators: greenhouse gas (GHG) emissions, land use and blue water use per household per week. Data were analysed using linear regression analyses.

SETTING

Three-dimensional virtual supermarket.

PARTICIPANTS

Dutch adults (≥ 18 years) who were responsible for grocery shopping in their household (n 395).

RESULTS

GHG emissions (-7·6 kg CO2-eq; 95 % CI -12·7, -2·5) and land use (-3·9 m2/year; 95 % CI -7·7, -0·2) were lower for the food purchases of participants in the nutrient profiling tax condition than for those in the control condition. Blue water use was not affected by the nutrient profiling tax. Moreover, the SSB tax had no significant effect on any of the environmental impact indicators.

CONCLUSIONS

A nutrient profiling tax based on Nutri-Score reduced the environmental impact of consumer food purchases. An SSB tax did not affect the environmental impact in this study.