Grocery store interventions to change food purchasing behaviors: a systematic review of randomized controlled trials

Do promotions of healthier or more sustainable foods increase sales? Findings from three natural experiments in UK supermarkets

BACKGROUND

Dietary changes are necessary to improve population health and meet environmental sustainability targets. Here we analyse the impact of promotional activities implemented in UK supermarkets on purchases of healthier and more sustainable foods.

METHODS

Three natural experiments examined the impact of promotional activities on sales of a) no-added-sugar (NAS) plant-based milk (in 199 stores), b) products promoted during 'Veganuary' (in 96 stores), and c) seasonal fruit (in 100 non-randomised intervention and 100 matched control stores). Data were provided on store-level product sales, in units sold and monetary value (£), aggregated weekly. Predominant socioeconomic position (SEP) of the store population was provided by the retailer. Analyses used interrupted time series and multivariable hierarchical mixed-effects models.

RESULTS

Sales of both promoted and total NAS plant-based milks increased significantly during the promotional period (Promoted:+126 units, 95%CI: 105-148; Overall:+307 units, 95%CI: 264-349). The increase was greater in stores with predominately low SEP shoppers. During Veganuary, sales increased significantly for plant-based foods on promotion (+60 units, 95%CI: 37-84), but not for sales of plant-based foods overall (dairy alternatives: -1131 units, 95%CI: -5821-3559; meat alternatives: 1403 units, 95%CI: -749-3554). There was no evidence of a change in weekly sales of promoted seasonal fruit products (assessed via ratio change in units sold: 0.01, 95%CI: 0.00-0.02), and overall fruit category sales slightly decreased in intervention stores relative to control (ratio change in units sold: -0.01, 95%CI: -0.01-0.00).

CONCLUSION

During promotional campaigns there was evidence that sales of plant-based products increased, but not seasonal fruits. There was no evidence for any sustained change beyond the intervention period.

Creating a healthy and sustainable food environment to promote plant-based food consumption: clear barriers and a gradual transition

BACKGROUND

A shift away from diets high in animal-based foods towards diets high in plant-based foods is desirable considering human health, environmental sustainability, and animal welfare. As the food environment plays a crucial role in shaping consumption patterns, understanding of how changes in the food environment can facilitate plant-based consumption is crucial for the so-called protein transition. The current study aims to garner insight into barriers and facilitators for food outlet managers to take action to stimulate plant-based consumption within a local food environment.

METHODS

Using a maximum-variation sample approach, we examined possible barriers and facilitators to promote plant-based consumption across different types of food outlets located within a geographically shared food environment (a city in the Netherlands). We conducted in-depth semi-structured interviews among food outlet managers and applied multi-stage thematic analysis to the interview transcripts.

RESULTS

Most managers underscored the urgency of shifting towards more plant-based diets, and perceived a growing demand for plant-based products. However, three barriers hindered most of them from taking decisive action: Managers' perception of low consumer demand for plant-based food options; fear of consumer resistance when stimulating plant-based food options; and limited behavioral agency to offer attractive plant-based food options. The few managers who made changes, or intend to make changes, are individuals with high intrinsic motivation, knowledge and skills.

CONCLUSIONS

The present work suggests the key for change towards a food environment stimulating plant-based consumption lies in addressing three (perceived) barriers shared among diverse outlets. These are partly different from barriers for stimulating healthy consumption in general. Furthermore, current changes appear to be driven incidentally by individuals who are motivated and able to stimulate more plant-based purchases among a small targeted group of consumers.

Are Dutch adults equally susceptible to nudging and pricing strategies? Secondary analyses of the Supreme Nudge parallel cluster-randomised controlled supermarket trial

BACKGROUND

Supermarket interventions are promising to promote healthier dietary patterns, but not all individuals may be equally susceptible. We explored whether the effectiveness of nudging and pricing strategies on diet quality differs by psychological and grocery shopping characteristics.

METHODS

We used data of the 12-month Supreme Nudge parallel cluster-randomised controlled supermarket trial, testing nudging and pricing strategies to promote healthier diets. Participants were Dutch speaking adults aged 30-80 years and regular shoppers of participating supermarkets (n = 12) in socially disadvantaged neighbourhoods. Data on psychological characteristics (food-related behaviours; price sensitivity; food decision styles; social cognitive factors; self-control) and grocery shopping characteristics (time spent in the supermarket; moment of the day; average supermarket visits; shopping at other retailers; supermarket proximity) were self-reported at baseline. These characteristics were tested for their moderating effects of the intervention on diet quality (scored 0-150) in linear mixed models.

RESULTS

We included 162 participants from intervention supermarkets and 199 from control supermarkets (73% female, 58 (± 10.8) years old, 42% highly educated). The interventions had no overall effect on diet quality. Only five out of 23 potential moderators were statistically significant. Yet, stratified analyses of these significant moderators showed no significant effects on diet quality for one of the subgroups and statistically non-significant negative effects for the other. Negative effects were suggested for individuals with lower baseline levels of meal planning (β - 2.6, 95% CI - 5.9; 0.8), healthy shopping convenience (β - 3.0, 95% CI - 7.2; 1.3), and healthy food attractiveness (β - 3.5, 95% CI - 8.3; 1.3), and with higher levels of price consciousness (β - 2.6, 95% CI - 6.2; 1.0) and weekly supermarket visits (β - 2.4, 95% CI - 6.8; 1.9).

CONCLUSIONS

Adults with varying psychological and grocery shopping characteristics largely seem equally (un)susceptible to nudging and pricing strategies. It might be that certain characteristics lead to adverse effects, but this is not plausible, and the observed negative effects were small and statistically non-significant and may be explained by chance findings. Verification of these findings is needed in real-world trials based on larger sample sizes and with the use of more comprehensive interventions.

TRIAL REGISTRATION

Dutch Trial Register ID NL7064, 30th of May, 2018, https://onderzoekmetmensen.nl/en/trial/20990.

What factors influence sustainable and healthy diet consumption? A review and synthesis of literature within the university setting and beyond

Globally, typical dietary patterns are neither healthy nor sustainable. Recognizing the key role of dietary change in reducing noncommunicable disease risk and addressing environmental degradation, it is crucial to understand how to shift individuals toward a sustainable and healthy diet (SHD). In this literature review, we introduced the concept of a SHD and outlined the dietary behaviors necessary to transition toward SHD consumption; we reviewed the literature on factors that may influence sustainable (and unsustainable) dietary behaviors in adults; and we developed a novel scoring system to rank factors by priority for targeting in future research. Given the significant potential to promote a sustainable and healthy dietary transition on the university campus-where factors that may impact dietary behaviors can be targeted at all levels of influence (i.e., individual, interpersonal, environmental, policy)-we narrowed our focus to this setting throughout. Aided by our novel scoring system, we identified conscious habitual eating, product price, food availability/accessibility, product convenience, self-regulation skills, knowledge of animal ethics/welfare, food promotion, and eating norms as important modifiable factors that may influence university students' dietary behaviors. When scored without consideration for the university population, these factors were also ranked as highest priority, as was modified portion sizes. Our findings offer insight into factors that may warrant attention in future research aimed at promoting SHDs. In particular, the high-priority factors identified from our synthesis of the literature could help guide the development of more personalized dietary behavioral interventions within the university setting and beyond.

Promoting healthful food purchases through in-store interventions: Empirical evidence from rural food deserts

Effective ways to promote healthful food intake in rural areas are understudied. The paper evaluated whether a two-component, in-store intervention designed to encourage healthy food purchases was associated with improved healthfulness scores of food items purchased by shoppers in rural food deserts. One component introduced a point-of-sales label that assigned a single numerical score to each food item facilitating direct comparisons of the product's nutrition with those of other products shelved around it. The other component was a one-day nutrition education workshop promoted within the store. Interventions took place in 2015 at two stores in rural counties in the U.S. Midwest. Four stores in similar communities were selected as the control group. We applied a difference-in-difference model to estimate changes in the healthfulness of food items purchased attributable to the intervention among shoppers at the treatment stores (n = 486) and control stores (n = 10,759) using store transaction data. Healthfulness of food items was measured in terms of food scores published by the Environmental Working Group on a 1-10 scale. Both components had minimal impacts on the scores, although 0.2 and 0.1 points increases in the score per item and score per dollar were statistically significant at the 1% level respectively. A year after the intervention, these small effects of the intervention further diminished compared to the immediately after implementation. Results suggest the average effects of intervention across the study communities had limited practical significance but benefited some rural residents who were exposed to the intervention.

Nudging plant-based alternatives to meat and dairy in a real-life online supermarket: A randomized controlled trial

A shift from predominantly animal-based to plant-based consumption can benefit both planetary and public health. Nudging may help to promote such a shift. This study investigated nudge effects on plant-based alternatives to meat and dairy in an online supermarket. We conducted a two-arm, parallel-group, randomized controlled real-life online supermarket trial. Each customer transaction was randomized to a control arm (regular online supermarket) or an intervention arm (addition of placement, hedonic property and dynamic social norm nudges promoting meat and dairy alternatives). Outcomes were the aggregate of meat and dairy alternative purchases (primary outcome), the number of meat purchases, dairy purchases, meat alternative purchases, and dairy alternative purchases (secondary), and retailer revenue (tertiary). Generalized linear mixed models with a Conway-Maxwell Poisson distribution were used to estimate incidence rate ratios (IRRs). Analyzed data included 8488 transactions by participants (n = 4,266 control arm, n = 4,222 intervention arm), out of which 2,411 (66%) were aged above 45 years, 5,660 (67%) were females, and 1,970 (23%) lived in socially disadvantaged neighborhoods. Intervention arm participants purchased 10% (IRR 1.10 (95% CI 0.99-1.23)) more meat and dairy alternatives and 16% (1.16 (0.99-1.36)) more meat alternatives than control arm participants, although these findings are not statistically significant. There was no difference in dairy alternative purchases (1.00 (0.90-1.10)). Intervention arm participants purchased 3% less meats (0.97 (0.93-1.02)) and 2% less dairy products (0.98 (0.95-1.02)) than control participants. Retailer revenue was not affected (0.98 (0.95-1.01)). Online nudging strategies alone did not lead to a statistically significant higher amount of plant-based purchases, but replication of this work is needed with increased study power. Future studies should also consider nudging strategies as part of a broader set of policies to promote plant-based purchases. TRIAL REGISTRATION: Prospectively registered on 14th of May 2022. ISRCTN16569242 (https://doi.org/10.1186/ISRCTN16569242).

Development of a Tool for Reporting Key Dietary Indicators from Sales Data in Remote Australian Aboriginal and Torres Strait Islander Community Stores

Reporting key dietary indicators from sales data can help us guide store decision makers in developing effective store policy to support healthier customer purchases. We aimed to develop a web-based reporting tool of key dietary indicators from sales data to support health-promoting policy and practice in stores in geographically remote Aboriginal and Torres Strait Islander communities. Tool development included identifying key dietary indicators (informed by sales data from 31 stores), community consultation (19 Aboriginal and Torres Strait Islander store directors and two store managers) and a web-build. Tool evaluation involved feedback interviews with stakeholders (25 store managers and two nutritionists). Key dietary indicators aligned with Australian Dietary Guideline food groupings and recommendations. An online portal for accessing and customising reports was built. Stakeholder feedback indicated that the strengths of the reports were the visuals, ease of interpretation, providing information that was not currently available and potential to increase capacity to support healthy food retailing. Difficulties were defining healthiness classification with alignment to other nutrition guidelines used and ensuring reports reached relevant store decision makers. This tool may be valuable to support store decision makers in identifying and prioritising nutrition issues and optimising the health-enabling attributes of stores.

Real-world nudging, pricing, and mobile physical activity coaching was insufficient to improve lifestyle behaviours and cardiometabolic health: the Supreme Nudge parallel cluster-randomised controlled supermarket trial

BACKGROUND

Context-specific interventions may contribute to sustained behaviour change and improved health outcomes. We evaluated the real-world effects of supermarket nudging and pricing strategies and mobile physical activity coaching on diet quality, food-purchasing behaviour, walking behaviour, and cardiometabolic risk markers.

METHODS

This parallel cluster-randomised controlled trial included supermarkets in socially disadvantaged neighbourhoods across the Netherlands with regular shoppers aged 30-80 years. Supermarkets were randomised to receive co-created nudging and pricing strategies promoting healthier purchasing (N = 6) or not (N = 6). Nudges targeted 9% of supermarket products and pricing strategies 3%. Subsequently, participants were individually randomised to a control (step counter app) or intervention arm (step counter and mobile coaching app) to promote walking. The primary outcome was the average change in diet quality (low (0) to high (150)) over all follow-up time points measured with a validated 40-item food frequency questionnaire at baseline and 3, 6, and 12 months. Secondary outcomes included healthier food purchasing (loyalty card-derived), daily step count (step counter app), cardiometabolic risk markers (lipid profile and HbA1c via finger prick, and waist circumference via measuring tape), and supermarket customer satisfaction (questionnaire-based: very unsatisfied (1) to very satisfied (7)), evaluated using linear mixed-models. Healthy supermarket sales (an exploratory outcome) were analysed via controlled interrupted time series analyses.

RESULTS

Of 361 participants (162 intervention, 199 control), 73% were female, the average age was 58 (SD 11) years, and 42% were highly educated. Compared to the control arm, the intervention arm showed no statistically significant average changes over time in diet quality (β - 1.1 (95% CI - 3.8 to 1.7)), percentage healthy purchasing (β 0.7 ( - 2.7 to 4.0)), step count (β - 124.0 (- 723.1 to 475.1), or any of the cardiometabolic risk markers. Participants in the intervention arm scored 0.3 points (0.1 to 0.5) higher on customer satisfaction on average over time. Supermarket-level sales were unaffected (β - 0.0 (- 0.0 to 0.0)).

CONCLUSIONS

Co-created nudging and pricing strategies that predominantly targeted healthy products via nudges were unable to increase healthier food purchases and intake nor improve cardiometabolic health. The mobile coaching intervention did not affect step count. Governmental policy measures are needed to ensure more impactful supermarket modifications that promote healthier purchases.

TRIAL REGISTRATION

Dutch Trial Register ID NL7064, 30 May 2018, https://www.onderzoekmetmensen.nl/en/trial/20990.

A Behaviorally Informed Mobile App to Improve the Nutritional Quality of Grocery Shopping (SwapSHOP): Feasibility Randomized Controlled Trial

BACKGROUND

Interventions targeting the nutritional quality of grocery shopping have the potential to help improve diet and health outcomes.

OBJECTIVE

This study aims to assess the feasibility and acceptability of receiving advice on healthier food purchases through SwapSHOP, a behaviorally informed smartphone app that allows users to scan barcodes of grocery products from the United Kingdom, providing nutritional information and personalized swap suggestions to encourage healthier purchases.

METHODS

We randomized adult volunteers in a 6-arm parallel-group controlled feasibility trial. Participants used the SwapSHOP app to record their grocery shopping during a 2-week run-in period and were individually randomized in a 3:1 ratio to either intervention or control arms within 3 strata related to a nutrient of concern of their choice: saturated fat (SFA), sugar, or salt. Participants randomized to the intervention received the SwapSHOP app with a healthier swap function, goal setting, and personalized feedback. Participants in the control group were instructed to use a simpler version of the app to log all their food purchases without receiving any guidance or advice. The primary outcome was the feasibility of progression to a full trial, including app use and follow-up rates at 6 weeks. The secondary outcomes included other feasibility outcomes, process and qualitative measures, and exploratory effectiveness outcomes to assess changes in the nutrient content of the purchased foods.

RESULTS

A total of 112 participants were randomized into 3 groups: SFA (n=38 intervention and n=13 control), sugar (n=40 intervention and n=15 control), and salt (n=5 intervention and n=1 control, not analyzed). The 2 progression criteria were met for SFA and sugar: 81% (30/37) and 87% (34/39) of intervention participants in the SFA and sugar groups, respectively, used the app to obtain healthier swaps, and 89% (68/76) of intervention participants and 96% (23/24) of control participants completed follow-up by scanning all purchases over the follow-up period. The process and qualitative outcomes suggested that the intervention was acceptable and has the potential to influence shopping behaviors. There were reductions of -0.56 g per 100 g (95% CI -1.02 to -0.19) in SFA and -1 g per 100 g (95% CI -1.97 to -0.03) in total sugars across all food purchases in the intervention groups.

CONCLUSIONS

People were willing to use the SwapSHOP app to help reduce sugar and SFA (but not salt) in their grocery shopping. Adherence and follow-up rates suggest that a full trial is feasible. Given the suggestive evidence indicating that the intervention resulted in reductions in sugars and SFA, a definitive trial is necessary to target improvements in health outcomes.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number ISRCTN13022312; https://doi.org/10.1186/ISRCTN13022312.

A systems framework for implementing healthy food retail in grocery settings

BACKGROUND

Food retailers can be reluctant to initiate healthy food retail activities in the face of a complex set of interrelated drivers that impact the retail environment. The Systems Thinking Approach for Retail Transformation (START) is a determinants framework created using qualitative systems modelling to guide healthy food retail interventions in community-based, health-promoting settings. We aimed to test the applicability of the START map to a suite of distinct healthy food marketing and promotion activities that formed an intervention in a grocery setting in regional Victoria, Australia.

METHODS

A secondary analysis was undertaken of 16 previously completed semi-structured interviews with independent grocery retailers and stakeholders. Interviews were deductively coded against the existing START framework, whilst allowing for new grocery-setting specific factors to be identified. New factors and relationships were used to build causal loop diagrams and extend the original START systems map using Vensim.

RESULTS

A version of the START map including aspects relevant to the grocery setting was developed ("START-G"). In both health-promoting and grocery settings, it was important for retailers to 'Get Started' with healthy food retail interventions that were supported by a proof-of-concept and 'Focus on the customer' response (with grocery-settings focused on monitoring sales data). New factors and relationships described perceived difficulties associated with disrupting a grocery-setting 'Supply-side status quo' that promotes less healthy food and beverage options. Yet, most grocery retailers discussed relationships that highlighted the potential for 'Healthy food as innovation' and 'Supporting cultural change through corporate social responsibility and leadership'.

CONCLUSIONS

Several differences were found when implementing healthy food retail in grocery compared to health promotion settings. The START-G map offers preliminary guidance for identifying and addressing commercial interests in grocery settings that currently promote less healthy foods and beverages, including by starting to address business outcomes and supplier relationships.

Purchasing sustainable palm oil products: narrowing the intention-behavior gap

Experts on palm oil production and utilization emphasize the role of consumer purchasing power in dealing with the environmental and social impacts of the palm oil crisis -that by increasing the demand for sustainable palm oil (SPO), greater supply will follow. However, research has identified a persistent intention-behavior gap. Even knowledgeable consumers do not always follow through on their intentions to purchase SPO. Utilizing the Capability-Opportunity Motivation model of Behavior (COM-B), this article reviews important variables contributing to this intention-behavior gap. While knowledge about palm oil and SPO (capability), perceived product availability (opportunity), and pro-green consumption attitudes (motivation) are important predictors of SPO purchasing intentions, increasing these factors has been insufficient in narrowing the intention-behavior gap. Campaigns can increase knowledge about palm oil and SPO, as well as build motivation around making the 'sustainable' choice, but are inadequate in addressing barriers around opportunity (e.g., ease of access to SPO products). In expressing their intent to purchase SPO products, consumers may underestimate the difficulties in being able to identify these consumables (e.g., palm oil often is not clearly labeled, sustainability status may not be obvious), and locate them. In this review, we argue that while consumer behavior is important, it is insufficient to power industry-wide change toward the utilization of SPO. Greater corporate responsibility is needed to increase use of SPO in products, and make consumables containing SPO more available, identifiable, and affordable for consumers. We also suggest that national procurement policies for SPO are likely to produce longer-lasting change.

Women Consumers' Views on Legislation to Restrict Prominent Placement and Multibuy Promotions of High Fat, Sugar, and Salt Products in England: A Qualitative Perspective

BACKGROUND

As part of the childhood obesity strategy, the UK Government has introduced regulations to restrict the ways high fat salt and sugar (HFSS) products can be promoted in retail settings from October 2022. This study explored (i) consumers' views on the likely impact of the UK legislation restricting the placement and promotion of HFSS products on their shopping behaviours and (ii) consumers' beliefs about who is responsible for healthy eating.

METHODS

Using a cross-sectional study design, qualitative semi-structured telephone interviews were conducted with a purposive sample of women who shopped at a discount supermarket. Thematic analysis was employed to identify key themes.

RESULTS

Participants' (n = 34) had a median age of 35 years and over half were in paid employment. Five themes were identified: (1) The legislation is acceptable, but people can still (and should be able to) buy HFSS items; (2) The legislation is likely to have more impact on shoppers who do not plan their shopping; (3) Affordability of healthy food is just as, or more, important than the legislation; (4) It's up to the individual to eat healthily; and (5) Government and retailers can better support consumers to make healthy choices.

CONCLUSION

Most participants were optimistic about the incoming regulations and believed that it would support consumers to make healthier food choices. Many raised concerns, however, that the high price of healthy foods and continued availability of unhealthy foods within the stores could undermine the legislation's benefits. Coupling the legislation with interventions to promote and reduce the costs of healthier products would go some way to ensure its success. Raising awareness about marketing strategies that play into consumer concerns for cost and autonomy could further increase acceptance of the policy.

Food insecurity in people living with obesity: Improving sustainable and healthier food choices in the retail food environment-the FIO Food project

At both UK and global level, dietary consumption patterns need to change to address environmental, health and inequality challenges. Despite considerable policy interventions, the prevalence of overweight and obesity in the United Kingdom has continued to rise with obesity now a leading cause of mortality and morbidity. Obesity prevalence is greater among those on lower incomes and the current UK food system, including government policy, does not effectively address this. Current behavioural approaches, without the support of structural changes in the system, may even widen the inequalities gap. Hence, using behavioural insights from those living with obesity and food insecurity, the project will explore potential avenues that can be applied in the food system to promote healthier choices in the food retail environment. The National Food Strategy report recommends that the UK food system should ensure "safe, healthy, affordable food; regardless of where people live or how much they earn". However, the association between food insecurity and the development of obesity is not well understood in relation to purchasing behaviours in the UK retail food environment, nor is the potential effectiveness of interventions that seek to prevent and reduce the impact of diet-induced health harms. The FIO Food (Food insecurity in people living with obesity - improving sustainable and healthier food choices in the retail food environment) project provides a novel and multi-disciplinary collaborative approach with co-development at the heart to address these challenges. Using four interlinked work packages, the FIO Food project will combine our knowledge of large-scale population data with an understanding of lived experiences of food shopping for people living with obesity and food insecurity, to develop solutions to support more sustainable and healthier food choices in the UK retail food environment.

Evaluating the impact of marketing interventions on sugar-free and sugar-sweetened soft drink sales and sugar purchases in a fast-food restaurant setting

BACKGROUND

Beverages high in added sugar, such as sugar-sweetened soft drinks, continue to be associated with various health issues. This study examines the effects of a manufacturer-initiated multicomponent intervention on the sales of sugar-free (SFD) and sugar-sweetened (SSD) soft drinks and the amount of sugar people purchase from soft drinks in a fast-food restaurant setting.

METHODS

A database of monthly sales data of soft drinks from January 2016 to December 2018 was obtained from three treatment and three control fast-food restaurants. A multicomponent intervention consisting of free coupons, point-of-purchase displays, a menu board, and two sugar-free replacements for sugar-sweetened soft drinks was introduced in August 2018 for five months in Western Sydney, Australia. A retrospective interrupted time series analysis was used to model the data and examine the effects of the interventions on SFD and SSD sales and their consequential impact on sugar purchases from soft drinks. The analyses were carried out for volume sales in litres and sugar in grams per millilitre of soft drinks sales. A comparison of these measures within the treatment site (pre- and post-intervention) and between sites (treatment and control) was conducted.

RESULTS

The interventions had a statistically significant impact on SFDs but not SSDs. On average, SFD sales in the treatment site were 56.75% higher than in the control site. Although SSD sales were lower in the treatment site, the difference with the control site was not statistically significant. The net reduction of 6.34% in the amount of sugar purchased from soft drinks between sites during the experimental period was attributed to the interventions.

CONCLUSIONS

The interventions significantly increased SFD sales and reduced sugar purchases in the short run. Aside from free coupons, the findings support the recommendation for fast food restaurants to nudge customers towards choosing SFDs through point-of-purchase displays and the replacement of popular SSDs with their SFD counterparts.

Preventing type 2 diabetes: A research agenda for behavioural science

AIMS

The aim of this narrative review was to identify important knowledge gaps in behavioural science relating to type 2 diabetes prevention, to inform future research in the field.

METHODS

Seven researchers who have published behaviour science research applied to type 2 diabetes prevention independently identified several important gaps in knowledge. They met to discuss these and to generate recommendations to advance research in behavioural science of type 2 diabetes prevention.

RESULTS

A total of 21 overlapping recommendations for a research agenda were identified. These covered issues within the following broad categories: (a) evidencing the impact of whole population approaches to type 2 diabetes prevention, (b) understanding the utility of disease-specific approaches to type 2 diabetes prevention such as Diabetes Prevention Programmes (DPPs) compared to generic weight loss programmes, (c) identifying how best to increase reach and engagement of DPPs, whilst avoiding exacerbating inequalities, (d) the need to understand mechanism of DPPs, (e) the need to understand how to increase maintenance of changes as part of or following DPPs, (f) the need to assess the feasibility and effectiveness of alternative approaches to the typical self-regulation approaches that are most commonly used, and (g) the need to address emotional aspects of DPPs, to promote effectiveness and avoid harms.

CONCLUSIONS

There is a clear role for behavioural science in informing interventions to prevent people from developing type 2 diabetes, based on strong evidence of reach, effectiveness and cost-effectiveness. This review identifies key priorities for research needed to improve existing interventions.

Influences of the community and consumer nutrition environment on the food purchases and dietary behaviors of adolescents: A systematic review

Adolescence is a period of increased autonomy over decision-making, including food choices, and increased exposure to influences outside the home, including the food environment. This review aims to synthesize the evidence for the influence of community nutrition environments, spatial access to food outlets, and consumer nutrition environments, environments inside food outlets, on adolescent food purchasing and dietary behaviors in high-income countries. Six databases were searched for articles published before January 2023. Results were synthesized using a vote-counting technique and effect direction plots that record the direction of the effect in relation to the anticipated relationship with health. Thirty-four observational and two intervention studies met the inclusion criteria. In the 13 studies assessing adolescent exposure to healthy community nutrition environments, results did not show clear associations with dietary and purchasing outcomes. Thirty studies assessed adolescents' exposure to unhealthy community nutrition environments with the majority (n = 17/30, 57%) reporting results showing that greater exposure to food outlets classified as unhealthy was associated with less healthy food purchases and dietary intakes. Inconsistent results were observed across the seven studies investigating associations with the consumer environment. Further research in these areas, including more high-quality intervention studies, may help to develop policy strategies to improve adolescents' dietary behaviors.

The impact of price promotions on confectionery and snacks on the energy content of shopping baskets: A randomised controlled trial in an experimental online supermarket

Overconsumption of foods high in fat, sugars, and salt (HFSS) poses a significant risk to health. The government in England has passed legislation that would limit some price promotions of HFSS foods within supermarkets, but evidence regarding likely impacts of these policies, especially in online settings, is limited. This study aimed to determine whether there were any differences in the energy and nutrient content of shopping baskets after removing promotions on HFSS foods in an online experimental supermarket. UK adults (n = 511) were asked to select food from four categories with a £10 budget in an online experimental supermarket: confectionery; biscuits and crackers; crisps, nuts and snacking fruit; cakes and tarts. They were randomly allocated to one of two trial arms: (1) promotions present (matched to promotion frequency seen in a major UK retailer) (n = 257), or (2) all promotions removed from all products within the target food categories (n = 254). The primary outcome analysis used linear regression to compare total energy (kcal) of items placed in shopping baskets when promotions were present vs. absent, while secondary analyses investigated differences in nutrients and energy purchased from individual food categories. Mean energy in food selected without promotions was 5156 kcal per basket (SD 1620), compared to 5536 kcal (SD 1819) with promotions, a difference of -552kcal (95%CIs: -866, -238), equivalent to 10%. There were no significant differences in energy purchased for any individual category between groups. No evidence was found of other changes in nutritional composition of baskets or of significant interactions between the impact of promotions and participant characteristics (gender, age, ethnicity) on energy purchased. Removing promotions on HFSS foods resulted in significantly less total energy selected in an online experimental supermarket study.

Real-life experiments in supermarkets to encourage healthy dietary-related behaviours: opportunities, challenges and lessons learned

BACKGROUND

Supermarkets are the primary source of food for many people yet their full potential as a setting to encourage healthy dietary-related behaviours remains underutilised. Sharing the experiences from research groups who have worked with supermarket chains to evaluate strategies that promote healthy eating could improve the efficiency of building such relationships and enhance the design quality of future research studies.

METHODS

A collective case study approach was used to synthesise experiences of engaging and sustaining research collaborations with national supermarket chains to test the effectiveness of health-focused in-store interventions. The collective narrative covers studies conducted in three high-income countries: Australia, the Netherlands and the United Kingdom.

RESULTS

We have distilled our experiences and lessons learned into six recommendations for conducting high quality public health research with commercial supermarket chains. These include: (i) using personal contacts, knowledge of supermarket activities and engaging executive management to establish a partnership and allowing time to build trust; (ii) using scientifically robust study designs with appropriate sample size calculations; (iii) formalising data exchange arrangements and allocating adequate resource for data extraction and re-categorisation; (iv) assessing effects at individual/households level where possible; (v) designing a mixed-methods process evaluation to measure intervention fidelity, dose and unintended consequences; and (vi) ensuring scientific independence through formal contract agreements.

CONCLUSIONS

Our collective experiences of working in non-financial partnerships with national supermarket chains could be useful for other research groups looking to develop and implement supermarket studies in an efficient manner. Further evidence from real-life supermarket interventions is necessary to identify sustainable strategies that can improve population diet and maintain necessary commercial outcomes.

Developing Co-Creation Research in Food Retail Environments: A Descriptive Case Study of a Healthy Supermarket Initiative in Regional Victoria, Australia

Research into the co-creation of healthy food retail is in its early stages. One way to advance co-creation research is to explore and understand how co-creation was applied in developing, implementing, and evaluating a heath-enabling initiative in a supermarket in regional Victoria, Australia. A case study design was used to explore and understand how co-creation was applied in the Eat Well, Feel Good Ballarat project. Six documents and reports related to the Eat Well, Feel Good Ballarat project were analyzed with findings from the focus groups and interviews. Motivations to develop or implement health-enabling supermarket initiatives differed among the participants. Participants considered that initial negotiations were insufficient to keep the momentum going and to propose the value to the retailers to scale up the project. Presenting community-identified needs to the supermarket helped gain the retailer's attention, whilst the co-design process helped the implementation. Showcasing the project to the community through media exposure kept the supermarket interested. Retailers' time constraints and staff turnover were considered significant barriers to partnership building. This case study contributes insights into applying co-creation to health-enabling strategies in food retail outlets using two co-creation frameworks.

Co-creation of health-enabling initiatives in food retail: academic perspectives

INTRODUCTION

Co-creation of healthy food retail comprises the systematic collaboration between retailers, academics and other stakeholders to improve the healthiness of food retail environments. Research into the co-creation of healthy food retail is in its early stages. Knowledge of the roles and motivations of stakeholders in intervention design, implementation and evaluation can inform successful co-creation initiatives. This study presents academic experiences of stakeholder roles and motivations in the co-creation of healthy food retail environments.

METHODS

Purposive sampling of academics with research experience in the co-creation of healthy food retail initiatives. Semi-structured interviews conducted between October and December 2021 gathered participants' experiences of multi-stakeholder collaborative research. Thematic analysis identified enablers, barriers, motivations, lessons and considerations for future co-creation of healthy food retail.

RESULTS

Nine interviewees provided diverse views and applications of co-creation research in food retail environments. Ten themes were grouped into three overarching areas: (i) identification of stakeholders required for changes to healthier food retail; (ii) motivations and interactions, which included the intrinsic desire to build healthier communities along with recognition of their work; and (iii) barriers and enablers included adequate resourcing, effective and trusting working relationships and open communications.

CONCLUSION

This study provides insights that could help future co-creation in healthy food retail environments. Trusting and respectful relationships and reciprocal acknowledgement between stakeholders are key practices in the co-creation process. These constructs should be considered in developing and testing a model that helps to systematically co-create healthy food retail initiatives that ensure all parties meet their needs while also delivering research outcomes.

The impact of altering restaurant and menu option position on food selected from an experimental food delivery platform: a randomised controlled trial

BACKGROUND

Overconsumption is one of the most serious public health challenges in the UK and has been linked to increased consumption of food ordered through delivery platforms. This study tested whether repositioning foods and/or restaurant options in a simulated food delivery platform could help to reduce the energy content of users' shopping basket.

METHODS

UK adult food delivery platform users (N = 9,003) selected a meal in a simulated platform. Participants were randomly allocated to a control condition (choices listed randomly) or to one of four intervention groups, (1) food options listed in ascending order of energy content, (2) restaurant options listed in ascending order of average energy content per main meal, (3) interventions 1 and 2 combined (4) interventions 1 and 2 combined, but food and restaurant options repositioned based on a kcal/price index to display options lower in energy but higher in price at the top. Gamma regressions assessed the impact of interventions on total energy content of baskets at checkout.

RESULTS

The energy content of participants' baskets in the control condition was 1382 kcals. All interventions significantly reduced energy content of baskets: Compared to control, repositioning both foods and restaurants purely based on energy content of options resulted in the greatest effect (-209kcal; 95%CIs: -248,-168), followed by repositioning restaurants (-161kcal; 95%CIs: -201,-121), repositioning restaurants and foods based on a kcal/price index (-117kcals; 95%CI: -158,-74) and repositioning foods based on energy content (-88kcals; 95%CI: -130,-45). All interventions reduced the basket price compared to the control, except for the intervention repositioning restaurants and foods based on a kcal/price index, which increased the basket price.

CONCLUSIONS

This proof-of-concept study suggests repositioning lower-energy options more prominently may encourage lower energy food choices in online delivery platforms and can be implemented in a sustainable business model.

The association of impulsivity with effects of the ChooseWell 365 workplace nudge intervention on diet and weight

Impulsivity is associated with unhealthy food choices. Nudge interventions in the food environment may be particularly helpful for individuals with high impulsivity. To examine if trait, choice, and action impulsivity were associated with the effectiveness of a workplace-based nudge intervention to improve diet and weight. This was a planned secondary analysis of 487 participants of ChooseWell 365, a randomized controlled trial that tested a 12-month nudge intervention to improve cafeteria purchases among hospital employees. Trait impulsivity was measured with the Barratt Impulsiveness Scale. Choice and action impulsivity were assessed with delay discounting and response inhibition tasks, respectively. Tertiles were generated for each measure. Multivariable regression models examined the association of impulsivity with cafeteria purchases [Healthy Purchasing Score (HPS)] over 12 months, dietary intake [Healthy Eating Index-2015 (HEI) score], and body mass index (BMI) measured at 12 months. Interaction terms tested differences in intervention effect by level of impulsivity. Participants with higher trait (p = .02) and choice (p < .001) impulsivity had lower baseline HPS than those with lower impulsivity. Employees of all impulsivity levels increased healthy eating, but higher trait impulsivity was associated with smaller increase in HPS over 12 months (p = .03). In the highest action impulsivity tertile, 12-month BMI increased less for intervention vs. control participants (0.3 vs. 0.5 kg/m2; p-interaction = .04). There were no interaction effects for trait or choice impulsivity. A workplace nudge intervention improved food choices among employees of all impulsivity levels and attenuated weight gain in those with higher action impulsivity.

Involving supermarkets in health promotion interventions in the Danish Project SoL. A practice-oriented qualitative study on the engagement of supermarket staff and managers

BACKGROUND

Supermarkets have been suggested as relevant settings for environmental and educational initiatives encouraging healthier shopping and eating decisions, but in the literature, limited attention has been paid to the context, perspectives, and everyday practices of supermarket staff. The aim of this study was to examine the engagement of supermarket staff in a health promotion project from a practice-oriented perspective.

METHODS

The study was based on qualitative data collected in the supermarket setting of Project SoL; a community-based health promotion project in Denmark. We conducted 26 in-depth interviews with store managers and other key staff members in seven participating supermarkets. In addition, we collected data on planning, implementation, and perceptions of supermarket staff of in-store interventions and other project-related activities. These field data included short telephone interviews, observational notes, photos, and audiotapes of meetings. Data were analysed from the perspective of practice theory.

RESULTS

Although supermarket staff found community-based health promotion meaningful to engage in, the study observed that their engagement was challenged by a business mindset, practical routines and structural requirements favouring sales promotion over health promotion. Nevertheless, there were also examples of how health promotion activities and ways of thinking were successfully incorporated in everyday staff practices during and after Project SoL.

CONCLUSIONS

Our findings point to both potentials and challenges for using supermarkets as settings for health promotion. The voluntary engagement of supermarket staff in community-based health projects cannot stand alone but should be supplemented by more long-lasting strategies and policies regulating this and other food environments. Context-sensitive and practice-oriented analyses in local food environments could inform such strategies and policies to make sure they target unwanted elements and practices and not just individual behavior.

Impact on alcohol selection and online purchasing of changing the proportion of available non-alcoholic versus alcoholic drinks: A randomised controlled trial

BACKGROUND

Increasing the availability of non-alcoholic options is a promising population-level intervention to reduce alcohol consumption, currently unassessed in naturalistic settings. This study in an online retail context aimed to estimate the impact of increasing the proportion of non-alcoholic (relative to alcoholic) drinks, on selection and purchasing of alcohol.

METHODS AND RESULTS

Adults (n = 737) residing in England and Wales who regularly purchased alcohol online were recruited between March and July 2021. Participants were randomly assigned to one of 3 groups: "25% non-alcoholic/75% alcoholic"; "50% non-alcoholic/50% alcoholic"; and "75% non-alcoholic/25% alcoholic," then selected drinks in a simulated online supermarket, before purchasing them in an actual online supermarket. The primary outcome was the number of alcohol units selected (with intention to purchase); secondary outcomes included actual purchasing. A total of 607 participants (60% female, mean age = 38 years [range: 18 to 76]) completed the study and were included in the primary analysis. In the first part of a hurdle model, a greater proportion of participants in the "75% non-alcoholic" group did not select any alcohol (13.1%) compared to the "25% non-alcoholic" group (3.4%; 95% confidence interval [CI] -2.09, -0.63; p < 0.001). There was no evidence of a difference between the "75% non-alcoholic" and the "50% non-alcoholic" (7.2%) groups (95% CI 0.10, 1.34; p = 0.022) or between the "50% non-alcoholic" and the "25% non-alcoholic" groups (95% CI -1.44, 0.17; p = 0.121). In the second part of a hurdle model in participants (559/607) selecting any drinks containing alcohol, the "75% non-alcoholic" group selected fewer alcohol units compared to the "50% non-alcoholic" (95% CI -0.44, -0.14; p < 0.001) and "25% non-alcoholic" (95% CI -0.54, -0.24; p < 0.001) groups, with no evidence of a difference between the "50% non-alcoholic" and "25% non-alcoholic" groups (95% CI -0.24, 0.05; p = 0.178). Overall, across all participants, 17.46 units (95% CI 15.24, 19.68) were selected in the "75% non-alcoholic" group; 25.51 units (95% CI 22.60, 28.43) in the "50% non-alcoholic" group; and 29.40 units (95% CI 26.39, 32.42) in the "25% non-alcoholic" group. This corresponds to 8.1 fewer units (a 32% reduction) in the "75% non-alcoholic" compared to the "50% non-alcoholic" group, and 11.9 fewer alcohol units (41% reduction) compared to the "25% non-alcoholic" group; 3.9 fewer units (13% reduction) were selected in the "50% non-alcoholic" group than in the "25% non-alcoholic" group. For all other outcomes, alcohol selection and purchasing were consistently lowest in the "75% non-alcoholic" group. Study limitations include the setting not being entirely naturalistic due to using a simulated online supermarket as well as an actual online supermarket, and that there was substantial dropout between selection and purchasing.

CONCLUSIONS

This study provides evidence that substantially increasing the proportion of non-alcoholic drinks-from 25% to 50% or 75%-meaningfully reduces alcohol selection and purchasing. Further studies are warranted to assess whether these effects are realised in a range of real-world settings.

TRIAL REGISTRATION

ISRCTN: 11004483; OSF: https://osf.io/qfupw.

Marketing Sustainability Analysis of Stores Participating in a Healthier Retail Food Program

OBJECTIVES

To examine how food retailers completing Shop Healthy NYC, a healthy food retail program, (1) changed availability, placement, and promotion of healthier food immediately after participation and (2) sustained changes 1-year postintervention.

METHODS

From 2014 to 2017, stores in 2 high-poverty New York City neighborhoods participated in a low-intensity intervention focused on in-store advertising or a high-intensity intervention to meet 7 criteria related to availability, placement, and promotion of healthy items. Stores were assessed preintervention (Pre), 1-month postintervention (Post 1), and 12-16 months postintervention (Post 2). Analyses were restricted to stores that completed the intervention and were assessed at all time points (n = 64). Changes were compared across time points.

RESULTS

Across stores participating in the low-intensity intervention, the ratio of unhealthy-to-healthy ads decreased from Pre to Post 1, and by Post 2 remained improved over baseline. Among stores participating in the high-intensity intervention, the median number of healthy criteria met increased from 3.5 to 6 from Pre to Post 1 and decreased to 5 at Post 2.

CONCLUSIONS

Improvements in the marketing and availability, placement, and promotion of healthy products are feasible but may require reinforcement and additional support over time.

Implementation of a food retail intervention to reduce purchase of unhealthy food and beverages in remote Australia: mixed-method evaluation using the consolidated framework for implementation research

BACKGROUND

Adoption of health-enabling food retail interventions in food retail will require effective implementation strategies. To inform this, we applied an implementation framework to a novel real-world food retail intervention, the Healthy Stores 2020 strategy, to identify factors salient to intervention implementation from the perspective of the food retailer.

METHODS

A convergent mixed-method design was used and data were interpreted using the Consolidated Framework for Implementation Research (CFIR). The study was conducted alongside a randomised controlled trial in partnership with the Arnhem Land Progress Aboriginal Corporation (ALPA). Adherence data were collected for the 20 consenting Healthy Stores 2020 study stores (ten intervention /ten control) in 19 communities in remote Northern Australia using photographic material and an adherence checklist. Retailer implementation experience data were collected through interviews with the primary Store Manager for each of the ten intervention stores at baseline, mid- and end-strategy. Deductive thematic analysis of interview data was conducted and informed by the CFIR. Intervention adherence scores derived for each store assisted interview data interpretation.

RESULTS

Healthy Stores 2020 strategy was, for the most part, adhered to. Analysis of the 30 interviews revealed that implementation climate of the ALPA organisation, its readiness for implementation including a strong sense of social purpose, and the networks and communication between the Store Managers and other parts of ALPA, were CFIR inner and outer domains most frequently referred to as positive to strategy implementation. Store Managers were a 'make-or-break' touchstone of implementation success. The co-designed intervention and strategy characteristics and its perceived cost-benefit, combined with the inner and outer setting factors, galvanised the individual characteristics of Store Managers (e.g., optimism, adaptability and retail competency) to champion implementation. Where there was less perceived cost-benefit, Store Managers seemed less enthusiastic for the strategy.

CONCLUSIONS

Factors critical to implementation (a strong sense of social purpose; structures and processes within and external to the food retail organisation and their alignment with intervention characteristics (low complexity, cost advantage); and Store Manager characteristics) can inform the design of implementation strategies for the adoption of this health-enabling food retail initiative in the remote setting. This research can help inform a shift in research focus to identify, develop and test implementation strategies for the wide adoption of health-enabling food retail initiatives into practice.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN 12,618,001,588,280.

Modifying an Open Science Online Grocery for parents of youth with anorexia nervosa: A proof-of-concept study

OBJECTIVE

For youth with anorexia nervosa (AN), remission requires high caloric goals to achieve weight restoration, consumption of a wide variety of calorically dense foods, and reintroduction of eliminated foods. Family-based treatment (FBT), the gold-standard treatment for youth with AN, empowers parents to renourish their child and restore them to health; yet, parents often report struggling with shifting meal planning and grocery shopping behaviors to focus on nutritional rehabilitation and weight restoration.

METHODS

This proof-of-concept study aimed to modify a simulated grocery store (Open Science Online Grocery [OSOG]) for parents of youth with AN and explore the acceptability and feasibility of its use as part of standard care. Study staff collaborated with six parent research partners to modify the OSOG prior to piloting it with participants. Participants were 10 parents of youth undergoing a first-time hospitalization for medical stabilization of AN or atypical AN. Parents completed a battery of measures and a semistructured interview assessing the acceptability and feasibility of OSOG.

RESULTS

Parents described the tool as credible and acceptable. Qualitative feedback highlighted common themes of caregiver burden, nutrition education, and acceptability of the tool.

DISCUSSION

Results point to the need for more work in supporting parents in Phase I of FBT.

PUBLIC SIGNIFICANCE

Families are instrumental in supporting youth to recover from anorexia nervosa. During treatment, parents are charged with selecting and serving their adolescent's meals, often requiring them to change grocery shopping and food preparation habits to meet their child's high caloric needs. Parents reported feeling overwhelmed by this task and noted struggling with learning different approaches to nourish their adolescent during an already stressful time. Collaboratively with parents, we modified a tool to support parents in shifting thier shopping habits, which they reported as being a helpful springboard in the early phase of treatment.

A Proof-of-Concept Pilot Test of a Behavioral Intervention to Improve Adherence to Dietary Recommendations for Cancer Prevention

OBJECTIVES

Prevention programs that can help adults improve the quality of their diets to reduce cancer risk are needed. This Phase IIa study prospectively tested a mHealth intervention designed to improve adherence to dietary quality guidelines for cancer prevention.

METHODS

All participants (N = 62) received nutrition education and a self-regulation skills curriculum, with a primary target of changing grocery shopping behavior. Using a randomized, factorial design, the study varied whether each of the following 4 components were added to the 20-week intervention: (1) location-triggered app messaging, delivered when individuals arrived at grocery stores, (2) reflections on benefits of change, delivered with extra coaching time and tailored app messages, (3) coach monitoring, in which food purchases were digitally monitored by a coach, and (4) involvement of a household member in the intervention.

RESULTS

Benchmarks were successfully met for recruitment, retention, and treatment acceptability. Across conditions, there were significant reductions in highly processed food intake (P < .001, η2 = .48), red and processed meat intake (P < .001, η2 = .20), and sugar-sweetened beverage intake (P = .008, η2 = .13) from pre-to post-treatment. Analyses examining whether each intervention component influenced change across time found that participants who received coach monitoring increased their intake of fruits, vegetables, and fiber, whereas those with no coach monitoring had less improvement (P = .01, η2 = .14). The improvement in red and processed meat was stronger among participants with household support ON, at a marginally significant level, than those with household support OFF (P = .056, η2 = .07).

CONCLUSION

This study showed feasibility, acceptability, and preliminary signals of efficacy of a remotely delivered intervention to facilitate adherence to dietary guidelines for cancer prevention and that coach monitoring and household support may be especially effective strategies. A fully powered clinical trial is warranted to test an optimized version of the intervention that includes nutrition education, self-regulation skills training, coach monitoring, and household member involvement.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04947150.

Consumer willingness to pay for healthier food products: A systematic review

Food retail strategies to improve the healthiness of food and beverage options may increase purchasing of healthier options and improve diets. Consumer demand for healthier options is an important determinant of the successful implementation and maintenance of healthy food retail interventions. A systematic review of peer-reviewed literature was undertaken to explore whether consumers are willing to pay more for healthier foods and to determine the key factors that influence willingness to pay. Fifteen studies reported the results of 26 experiments providing willingness to pay estimates for healthier food products across a range of food retail environments. Twenty three out of the 26 experiments included in this review (88.5%) found consumers would pay a 5.6% to 91.5% (mean 30.7%) price premium for healthier foods. Studies consistently found a positive willingness to pay for foods with reduced fat and wholegrains with additional fruit and vegetables, while willingness to pay for foods with reduced salt or a combination of low fat and sugar, or salt showed mixed results. Adults over 60 years, females, those living with obesity, and consumers who aim to maintain a healthy lifestyle were more likely to pay a price premium for healthier food, whereas younger consumers, consumers with healthy weight, and consumers with higher levels of education were less likely to pay higher prices. The results of this review contribute to our understanding of consumer preferences for healthier products and provide information to retailers on consumer surplus (benefits) associated with the provision of healthier food alternatives.

The revised Healthy Purchase Index (r-HPI): a validated tool for exploring the nutritional quality of household food purchases

BACKGROUND

The Healthy Purchase Index (HPI) assesses the nutritional quality of food purchases (FP) from food group expenditure shares only. However, it was developed from the FP of a disadvantaged population.

OBJECTIVE

To adapt and validate the HPI for a general population.

METHODS

FP were obtained from a representative sample of French households (Kantar WorldPanel) subdivided into two subsamples. The first sample (n = 4375) was used to adapt and validate the score; the second sample (n = 2188) was used to test external validity. The revised-HPI (r-HPI) includes 2 subscores: the diversity subscore and the quality subscore. Diversity subscore points were awarded when expenditure shares were above the 25th percentile for 5 food groups ("Fruits", "Vegetables", "Starches", "Dairy", "Meat, Fish and Eggs"). Regression models between the expenditure shares of each food group and the Mean Adequacy Ratio (MAR) and the Mean Excess Ratio (MER) of FP were used to select quality subscore components and define cut-offs for point allocation. Construct validity was assessed on the first sample using Spearman's correlations between the r-HPI and the four nutritional quality indicators (NRF9.3, MAR, MER, energy density), and also by comparing the r-HPI of monthly FP of sub-populations defined by criteria known to influence diet quality (age, gender, income, education) and between households having a monthly food basket of higher (MAR > median and MER and energy density < median) vs. lower nutritional quality within the population, using Wilcoxon tests or pairwise comparisons of contrasts. External validity was tested by performing the same analyses on the 2nd sample of 2188 households.

RESULTS

The adaptation led to include new components (e.g. red meat) and define new cut-offs (e.g. - 1 point when budget share for red meat > 21%). The r-HPI (mean = 6.50 ± 3.58) was strongly correlated with NRF9.3, MAR, MER and energy density (0.59, 0.52, - 0.41 and - 0.65, respectively, p < 0.01) and poorly correlated with total energy content (- 0.096, p < 0.001). The r-HPI was significantly higher in women (β = 1.41 [0.20], p < 0.01), households having a food basket of higher nutritional quality (β = 4.15 [0.11], p < 0.001), and increased significantly with age, income and education levels. Similar results were obtained in the 2nd sample.

CONCLUSION

We showed the validity of the r-HPI in a large sample of French households. As it does not require food quantity or nutrient content, it can be used as a valuable tool to explore FP behaviours. Cut-offs can be used in health promotion to provide nutri-economic counselling.

Encouraging Healthier Food and Beverage Purchasing and Consumption: A Review of Interventions within Grocery Retail Settings

This review identifies the most promising intervention strategies for promoting the purchase and consumption of healthier items within U.S. grocery retail settings, with a particular focus on those strategies that may be most effective when implemented within SNAP-authorized retail settings. Searches of nine electronic databases, as well as forward and backward searches, yielded 1942 studies. After being screened, 73 peer-reviewed academic articles were identified for inclusion. Of these, 33 analyzed single-component interventions, while 40 assessed multi-component interventions. The following unique intervention types were considered as evaluated in these studies for their ability to increase healthy item purchasing and consumption: (1) nutrition scoring, (2) nutritional messaging, (3) non-nutritional messaging, (4) endcaps and secondary placement, (5) point-of-sale interventions, (6) increased stocking, (7) food tasting and demonstrations, (8) nutrition education, and (9) placement on shelf interventions. Nutritional scoring and nutritional messaging emerged as the most rigorously tested and effective intervention strategies. Other strategies warrant more research attention. Simple intervention strategies, as opposed to complex ones, yield the most successful results and minimize shopper burden. Therefore, these strategies should be reviewed for policy implementation within SNAP-authorized grocery retailers.

Does promoting plant-based products in Veganuary lead to increased sales, and a reduction in meat sales? A natural experiment in a supermarket setting

OBJECTIVE

To explore changes in plant-based and meat product sales during and after implementation of a multi-component in-store intervention implemented by a major UK food retailer. Secondary objectives included exploring differences by store format and area affluence.

DESIGN

The intervention increased the visibility, accessibility, affordability and availability of a selection of plant-based products. Unit sales of plant-based and meat products during the intervention (January 2021) were compared with pre- (November 2020) and post-intervention (February and March 2021). Non-meat product sales were assessed as a control. Negative binomial mixed models were used to explore sales changes and differences by store format or affluence.

SETTING

The intervention was applied in a real-world supermarket setting during Veganuary.

PARTICIPANTS

Stores that applied the full intervention (n 154) were included for analysis. Weekly sales data for each store were obtained from the retailer.

RESULTS

Average weekly unit sales of plant-based products increased significantly (57 %) during the intervention period (incidence rate ratio (IRR) 1·52 (95 % CI1·51, 1·55)). Plant-based product sales decreased post-intervention but remained 15 % higher than pre-intervention (IRR 1·13 (95 % CI 1·12, 1·14)). There was no significant change in meat sales according to time period. The increase in plant-based product sales was greatest at superstores (58 %), especially those located in below average affluence areas (64 %).

CONCLUSIONS

Results suggest that increasing visibility, accessibility, affordability and availability of plant-based products led to increased sales, with evidence of lasting effects. No significant changes in meat sales were observed. Variation according to store format and area affluence indicates targeted intervention approaches are needed.

Evaluation of two social norms nudge interventions to promote healthier food choices in a Canadian grocery store

The objective of this study was to determine the impact of two nudge interventions on customers’ produce purchases at a rural Canadian grocery store. A pre- and post-intervention observational study design was used. Sales data were gathered before and after the staggered implementation of two nudge-based interventions to encourage produce purchases: grocery cart dividers to encourage shoppers to fill one-third of their cart with produce and grocery cart plaques with information about how many fruits and vegetables were typically purchased in the store. The proportion of total sales accounted for by produce was compared between baseline and implementation of the first intervention (Phase 1), between implementation of the first intervention and the addition of the second intervention (Phase 2), and between baseline and post-implementation of both interventions together. There was a 5% relative increase (0.5% absolute increase) in produce spending between baseline and post-implementation of both interventions (10.3% to 10.8%, p < 0.001, 95% CI 0.2%, 0.7%). Intervention phase-specific produce spending showed no significant change in the percentage of produce spending from baseline to Phase 1 of the intervention, and an 8% relative increase (0.8% absolute increase) in the percentage of produce spending from Phase 1 to Phase 2 of the intervention (10.3% to 11.1%, p < 0.001, 95% CI 0.5, 1.1%). Simple, low-cost nudge interventions were effective at increasing the proportion of total grocery spend on produce. This study also demonstrated that partnerships with local businesses can promote healthier food choices in rural communities in Canada.

Co-creation of healthier food retail environments: A systematic review to explore the type of stakeholders and their motivations and stage of engagement

OBJECTIVE

To synthesize peer-reviewed literature that utilize co-creation principles in healthy food retail initiatives.

METHODS

Systematic review of six databases from inception to September 2021. Screening and quality assessment were carried out by two authors independently. Studies were included if they were conducted in food retail stores, used a collaborative model, and aimed to improve the healthiness of the food retail environment. Studies excluded were implemented in restaurants, fast food chains, or similar or did not utilize some form of collaboration. Extracted data included the type of stakeholders engaged, level of engagement, stakeholder motivation, and barriers and enablers of the co-creation process.

FINDINGS

After screening 6951 articles by title and abstract, 131 by full text, 23 manuscripts that describe 20 separate studies from six countries were included. Six were implemented in low-income communities and eight among Indigenous people groups. A common aim was to increase access to, and availability of, healthy products. A diverse range of co-creation approaches, theoretical perspectives, and study designs were observed. The three most common stakeholders involved were researchers, corporate representatives or store owners, and governments.

CONCLUSIONS

Some evidence exists of the benefits of co-creation to improve the healthiness of food retail environments. The field may benefit from structured guidance on the theory and practice of co-creation.

Optimizing an mHealth Intervention to Change Food Purchasing Behaviors for Cancer Prevention: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Dietary intake is a powerful modifiable factor that influences cancer risk; however, most US adults do not adhere to dietary guidelines for cancer prevention. One promising pathway for improving dietary adherence is targeting grocery shopping habits. Interventions might facilitate healthy grocery choices, with a combination of mHealth and traditional methods, by promoting the salience of dietary goals while shopping, enhancing motivation to make dietary changes, and increasing household support for healthy food purchasing.

OBJECTIVE

This pilot study will assess feasibility and acceptability of intervention components designed to improve adherence to dietary guidelines for cancer prevention (preliminary aim). The primary aim of the study is to quantify the effect of each intervention component, individually and in combination, on dietary intake (primary aim) and grocery store food purchases (exploratory aim). Mediation analyses will be conducted to understand the mechanisms of action (goal salience, motivation, and household support-secondary aims). The overarching goal is to optimize an mHealth intervention to be tested in a future fully powered clinical trial.

METHODS

The study enrolled adults (N=62) with low adherence to dietary recommendations for cancer prevention. In a 20-week program, all participants attend a nutrition education workshop and receive weekly educational messages through an app. A factorial design is used to test 4 intervention components: (1) location-triggered messages: educational messages are delivered when arriving at grocery stores; (2) reflections on the benefits of change: content is added to messages to encourage reflection on anticipated benefits of healthy eating, and participants attend an additional workshop session and 3 coach calls on this topic; (3) coach monitoring: food purchases are monitored digitally by a coach who sends personalized weekly app messages and conducts 3 coaching calls that focus on feedback about purchases; and (4) household support: another adult in the household receives messages designed to elicit support for healthy food purchasing, and support is addressed in 3 coach calls and an extra workshop session attended by the index participant and household member. Assessments are completed at weeks 0, 10, and 20 using self-report measures, as well as objective capture of grocery data from the point of purchase using store loyalty accounts.

RESULTS

The National Cancer Institute funded this study (R21CA252933) on July 7, 2020. Participant recruitment began in the spring of 2021 and concluded with the successful enrollment of 62 participants. Data collection is expected to be completed in the summer of 2022, and results are expected to be disseminated in the summer of 2023.

CONCLUSIONS

The results of this study will inform the development of scalable interventions to lower cancer risk via changes in dietary intake.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04947150; https://clinicaltrials.gov/ct2/show/NCT04947150.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39669.

Suggested explanations for the (in)effectiveness of nutrition information interventions among adults with a low socioeconomic status: a scoping review

Unhealthy diets are a major threat to population health and are especially prevalent among those with a low socioeconomic status (SES). Health promotion initiatives often rely on nutrition information interventions (NIIs), but are usually less effective among adults with a low SES than in their high-SES counterparts. Explanations for this lower effectiveness are set out in extant studies. These have been conducted across a wide range of disciplines and subject fields and using a variety of methodological approaches. We have therefore conducted a scoping review to identify and synthesise the following: (1) explanations suggested in studies carried out in high-income countries for why NIIs are (in)effective among adults with a low SES and (2) whether these suggested explanations were studied empirically. Eight databases were searched for relevant studies published since 2009 across various disciplines. This identified 4951 papers, 27 of which were included in our review after screening. Only fifteen of these proposed an explanation for the (in)effectiveness of NIIs among adults with a low SES. The following four main themes were uncovered: health literacy, economic resources, social resources and convenience. Ten studies tested their explanations empirically, but the results were inconsistent. The reasons why NIIs are (in)effective among low-SES adults are therefore still largely unclear. Also, current literature predominantly relies on individualistic explanations, most notably focusing on psychological and economic attributes. Consequently, if the effectiveness of NIIs among low-SES populations is to be improved, future studies should examine a wider range of explanations and test them systematically and empirically.

Can in-store interventions reduce the socioeconomic gap in fruit and vegetable purchases in grocery stores? A descriptive study of volume sales from 2012 to 2020 in Norway's largest grocery store chain

Fruits and vegetable (FVs) consumption is an essential determinant of health, and intake is strongly patterned by socioeconomic status (SES). Inside grocery store interventions have increasingly been explored to promote healthier diets, especially for people with lower SES. This study describes how the supermarket chain Kiwi used a combination of in-store interventions to increase annual sales of FVs between 2012 and 2020. In particular, this study examined how sales developed in counties with different demographic characteristics (e.g., education, income, overweight and obesity, and self-reported FVs consumption level) in order to evaluate whether the effect differs between different populations. The primary outcome measurement was annual volume sales, adjusted for new stores opening and closing during the study period, also called like-for-like sales. The study has used a descriptive study design. The chain used interventions such as better placement, promoting healthy foods, giving out discounts, and placing "on the go" FVs and cups with portioned FVs at the cash registry. Results show that like-for-like volume sales of FVs grew by 34.1% during the study period. The increase was especially strong for vegetables, which increased by 41.8%, compared to fruits and berries, which increased by 25%. Sales increased for all eleven counties in Norway. Using the Spearman correlation, a moderately positive association was found between the number of overweight or obese people in counties and the development in FVs sales. To conclude, in-store interventions positively impacted FVs sales. More research in an experimental context is needed to determine if interventions may reduce the socioeconomic gap in FVs consumption.

Assessing the Influence of Food Insecurity and Retail Environments as a Proxy for Structural Racism on the COVID-19 Pandemic in an Urban Setting

A collaborative partnership launched the Great Grocer Project (GGP) in March 2021 in Detroit, Michigan where health inequities, including deaths due to COVID-19, have historically been politically determined and informed by socially entrenched norms. Institutional and structural racism has contributed to a lack of diversity in store ownership among Detroit grocers and limited access to high-quality, affordable healthy foods as well as disparate food insecurity among Detroit residents. The GGP seeks to promote Detroit's healthy grocers to improve community health and economic vitality through research, programs, and policies that have the potential to advance health equity. A cross-sectional design was used to explore relationships between scores from the Nutrition Environment Measures Surveys-Stores (NEMS-S) in 62 stores and city-level data of COVID-19 cases and deaths as well as calls to 211 for food assistance. Regression and predictive analyses were conducted at the ZIP code level throughout the city to determine a relationship between the community food environment and food insecurity on COVID-19 cases and deaths. COVID-19 cases and deaths contributed to greater food insecurity. The use of ZIP code data and the small sample size were limitations within this study. Causation could not be determined in this study; therefore, further analyses should explore the potential effects of individual grocery stores on COVID-related outcomes since a cluster of high-scoring NEMS-S stores and calls to 211 for food security resources inferred a potential protective factor. Poor nutrition has been shown to be associated with increased hospitalizations and deaths due to COVID-19. It is important to understand if a limited food environment can also have a negative effect on COVID-19 rates and deaths. Lessons learned from Detroit could have implications for other communities in using food environment improvements to prevent an uptick in food insecurity and deaths due to COVID-19 and other coronaviruses.

Implementing a Rural Natural Experiment: A Protocol for Evaluating the Impacts of Food Coops on Food Consumption, Resident's Health and Community Vitality

Background: Local food environments are recognized by experts as a determinant of healthy eating. Food cooperatives (coop) can promote the accessibility to healthier foods and thus improve the health of the population, particularly in remote rural communities. Objective: To measure the effects of implementing a food coop in a disadvantaged community with poor access to food. We have two main research questions: (1). Does the establishment of a food coop in rural areas described as food deserts have an impact on accessibility, frequency of use, food consumption, food quality, and ultimately the health of individuals? (2). Does the establishment of a food coop in rural areas described as food deserts have an impact on food security and community vitality? Design: A natural experiment with a mixed pre/post method will be used. The sample is composed of households that came from geographically isolated communities (population: 215 to 885 inhabitants) which qualified as food deserts and located in rural areas of Quebec (Canada). All communities plan to open a food coop (in the years 2022–2023), and as their opening will be staggered over time, participants from communities with a new food coop (intervention) will be compared to communities awaiting the opening of their food coop (control). Data collection was carried out at three time points: (1) before; (2) 1 to 5 months after; and (3) 13 to 17 months after the opening of the coop. Questionnaires were used to measure sociodemographic variables, dietary intake, residents’ health, and community vitality. Semi-structured interviews were conducted with community stakeholders. Results: Few natural experiments have been conducted regarding the impact of implementing food coops. Gathering concrete data on the effectiveness and processes surrounding these interventions through natural experiments will help to quantify their impact and guide knowledge users and policymakers to make more informed decisions.

The potential of food environment policies to reduce socioeconomic inequalities in diets and to improve healthy diets among lower socioeconomic groups: an umbrella review

Socioeconomic inequalities in diets need to be tackled to improve population diets and prevent obesity and diet-related non-communicable diseases. The potential of food environment policies to reduce such inequalities has to date however not been appraised. The objective of this umbrella review was to assess the impact of food environment policies on socioeconomic inequalities in diets and to identify knowledge gaps in the existing literature, using the Healthy Food Environment Policy Index as a conceptual framework. The policies considered in the umbrella review are within six domains: 1) food composition 2) food labelling 3) food promotion 4) food provision 5) food retail 6) food pricing. A systematic search for systematic literature reviews on the effect of food environment policies on dietary-related outcomes across socioeconomic groups and published in English between 2004 and 2019 was conducted. Sixteen systematic literature reviews encompassing 159 primary studies were included, covering food composition (n = 2), food labelling (n = 3), food provision (n = 2), food prices (n = 13) and food in retail (n = 4). Quality assessment using the “Assessing the Methodological Quality of Systematic Reviews” quality rating scale showed that review quality was mainly low or critically low. Results suggest that food taxation may reduce socioeconomic inequalities in diets. For all other policy areas, the evidence base was poor. Current research largely fails to provide good quality evidence on impacts of food environment policies on socioeconomic inequalities in diets. Research to fill this knowledge gap is urgently needed.

Removing seasonal confectionery from prominent store locations and purchasing behaviour within a major UK supermarket: Evaluation of a nonrandomised controlled intervention study

BACKGROUND

The proportion of energy from free sugars and saturated fat currently exceeds the UK-recommended intake across all age groups. Recognising the limits of reformulation programmes, the government in England has announced their intention to introduce legislation to restrict the promotion of foods high in free sugars, salt, and saturated fats in prominent store locations. Here, we evaluated a grocery store intervention to remove seasonal confectionery from prominent locations within a major UK supermarket.

METHODS AND FINDINGS

A nonrandomised controlled intervention study with interrupted time series (ITS) analysis was used. Data were analysed from 34 intervention stores located in 2 London boroughs and 151 matched control stores located elsewhere in the UK owned by the same retailer. Stores were matched based on store size and overall sales during the previous year. Between 15 February 2019 and 3 April 2019 (before Easter), stores removed free-standing promotional display units of seasonal confectionery from prominent areas, although these products were available for purchase elsewhere in the store. Store-level weekly sales (units, weight (g), and value (£)) of seasonal chocolate confectionery products were used in primary analyses, with data from 1 January 2018 to 24 November 2019. Secondary outcomes included total energy, fat, saturated fat, and sugars from all in-store purchases. Multivariable hierarchical models were used to investigate pre/post differences in weekly sales of confectionery in intervention versus control stores. ITS analyses were used to evaluate differences in level and trends after intervention implementation. Over a preintervention baseline period (15 February 2018 to 3 April 2018), there were no significant differences in sales (units, weight, and value) of all chocolate confectionery between intervention versus control stores. After intervention implementation, there was an attenuation in the seasonal increase of confectionery sales (units) in intervention stores compared to control (+5% versus +18%; P < 0.001), with similar effects on weight (g) (+12% versus +31%; P < 0.001) and value (£) (-3% versus +10%; P < 0.001). ITS analyses generally showed statistically significant differences in the level at the point of intervention (P ranges 0.010 to 0.067) but also in the trend afterwards (P ranges 0.024 to 0.053), indicating that the initial difference between intervention and control stores reduced over time. There was a significant difference in level change in total energy sold, adjusted for the total weight of food and drink (kcal/g, P = 0.002), and total fat (fat/g) (P = 0.023), but no significant changes in saturated fat or sugars from total sales in ITS models. There was no evidence that the main results varied across store deprivation index. The limitations of this study include the lack of randomisation, residual confounding from unmeasured variables, absolute differences in trends and sales between intervention versus control stores, and no independent measures of intervention fidelity.

CONCLUSIONS

Removal of chocolate confectionery from prominent locations was associated with reduced purchases of these products, of sufficient magnitude to observe a reduction in the energy content of total food purchases. These results from a "real-world" intervention provide promising evidence that the proposed legislation in England to restrict promotions of less healthy items in prominent locations may help reduce overconsumption.

TRIAL REGISTRATION

https://osf.io/br96f/.

Testing availability, positioning, promotions, and signage of healthier food options and purchasing behaviour within major UK supermarkets: Evaluation of 6 nonrandomised controlled intervention studies

BACKGROUND

Governments are increasingly looking for policies to change supermarket environments to support healthier food purchasing. We evaluated 6 interventions within major United Kingdom grocery stores, including availability, positioning, promotions, and signage strategies to encourage selection of healthier products.

METHODS AND FINDINGS

Nonrandomised controlled study designs were used, except for one intervention that was rolled out nationwide using a pre/post within-store design. Store-level weekly sales (units, weight (g), and value (£)) of products targeted in the interventions were used in primary analyses using multivariable hierarchical models and interrupted time series (ITS) analyses. Stocking low fat chips next to regular chips was associated with decreases in sales of regular chips (units) in intervention versus control stores (-23% versus -4%; P = 0.001) with a significant level change in ITS models (P = 0.001). Increasing availability of lower energy packs of biscuits was associated with increased sales but reduced sales of regular biscuits in intervention versus control stores (lower energy biscuits +18% versus -2%; P = 0.245; regular biscuits -4% versus +7%; P = 0.386), although not significantly, though there was a significant level change in ITS models (P = 0.004 for regular biscuits). There was no evidence that a positioning intervention, placing higher fibre breakfast cereals at eye level was associated with increased sales of healthier cereal or reduced sales of regular cereal. A price promotion on seasonal fruits and vegetables showed no evidence of any greater increases in sales of items on promotion in intervention versus control stores (+10% versus +8%; P = 0.101) but a significant level change in ITS models (P < 0.001). A nationwide promotion using Disney characters was associated with increased sales of nonsugar baked beans (+54%) and selected fruits (+305%), with a significant level change in ITS models (P < 0.001 for both). Shelf labels to highlight lower sugar beverages showed no evidence of changes in purchasing of lower or higher sugar drinks. These were all retailer-led interventions that present limitations regarding the lack of randomisation, residual confounding from unmeasured variables, absolute differences in trends and sales between intervention versus control stores, and no independent measures of intervention fidelity.

CONCLUSIONS

Increasing availability and promotions of healthier alternatives in grocery stores may be promising interventions to encourage purchasing of healthier products instead of less healthy ones. There was no evidence that altering positioning within an aisle or adding shelf edge labelling is associated with changes in purchasing behaviours.

TRIAL REGISTRATION

https://osf.io/br96f/.

Sparking Change: Evaluating the effectiveness of a multi-component intervention at encouraging more sustainable food behaviors

Facilitating the adoption of more sustainable food behaviors is key in order to reduce pressure on nature and improve public health. Food businesses that interact directly with consumers are well placed to enable a positive change in food behaviors. The present study evaluates the effectiveness of a 9-week multi-component behavioral intervention implemented by a large UK food retailer. Three food behaviors were explored: meat consumption, food waste and scratch cooking. Evaluation methods comprise of surveys issued pre-intervention, at intervention-end and at delayed follow-up (3 months after intervention end), and focus groups where participants were divided according to life-stage (pre-family, family, retired). Results show the intervention mitigated individual barriers to change and had a positive impact on awareness, intention and behavior which lasted beyond intervention-end. Participants reported reducing their meat consumption and food waste and cooking more frequently from scratch. Findings indicate that the online community, 'ask the expert' videos and product samples were the most impactful intervention components, while recipes and cook-alongs were less effective. This study provides an effective and feasible intervention which could be implemented and scaled by food companies. While behavioral interventions offer a positive opportunity for companies to drive consumer behavior change, structural and cultural changes to the food environment will be needed to facilitate long-term change at scale.

A Proposed Research Agenda for Promoting Healthy Retail Food Environments in the East Asia-Pacific Region

PURPOSE OF REVIEW

This paper aimed to summarise existing literature on strategies to improve the healthiness of retail food environments in the East Asia and Pacific (EAP) region, and propose a prioritised research agenda on this topic.

RECENT FINDINGS

Little research on retail food environments has been conducted in the EAP region. Several approaches for measuring retail food environments were identified, although none have been tailored to the EAP context. A small number of policies and initiatives to promote healthy retail food environments have been implemented in EAP. Lessons learnt from successful implementation of initiatives in other regions could be applied in EAP. Retail food environments have a strong influence on food choices and health outcomes. Research can contribute to efforts to improve the healthiness of retail food environments in EAP by (1) describing the current state of retail food environments to highlight areas of good practice and concern and (2) identifying policies and initiatives that are likely to be effective, and mechanisms for their successful implementation.

The use of food swaps to encourage healthier online food choices: a randomized controlled trial

BACKGROUND

Online grocery stores offer opportunities to encourage healthier food choices at the moment that consumers place a product of their choice in their basket. This study assessed the effect of a swap offer, Nutri-Score labeling, and a descriptive norm message on the nutrient profiling (NP) score of food choices in an online food basket. Additionally explored was whether these interventions made it more motivating and easier for consumers to select healthier foods and whether potential effects were moderated by consumer health interest.

METHODS

Hypotheses were tested with a randomized controlled trial (RCT) in a simulated online supermarket. Dutch participants (n = 550) chose their preferred product out of six product options for four different categories (breakfast cereals, crackers, pizza, and muesli bars). Participants were randomly allocated to one of eight groups based on the interventions in a 2 (Nutri-Score: present, not present) X 2 (swap offer: present, not present) X 2 (norm message: present, not present) between subject design. The primary outcome was the difference in combined NP score of product choices, for which a lower score represented a healthier product.

RESULTS

Swap offer (B = - 9.58, 95% CI: [- 12.026; - 7.132], Ƞ² = 0.098) and Nutri-Score labeling (B = - 3.28, 95% CI: [- 5.724; -.829], Ƞ² = 0.013) significantly improved the combined NP score compared to the control condition (NP score M = 18.03, SD = 14.02), whereas a norm message did not have a significant effect (B = - 1.378, 95% CI [- 3.825; 1.070], Ƞ² = 0.002). No evidence was found that interventions made it more motivating or easier for consumers to select healthier food, but situational motivation significantly influenced the healthiness score of food choices for both swap offer (b = - 3.40, p < .001) and Nutri-Score (b = - 3.25, p < .001). Consumer health interest only significantly moderated the influence of Nutri-Score on ease of identifying the healthy food option (b = .23, p = .04).

CONCLUSIONS

Swap offer and Nutri-Score labeling were effective in enhancing healthy purchase behavior in the online store environment.

TRIAL REGISTRATION

This study was retrospectively registered in the ISRCTN database on 02-09-2021 ( ISRCTN80519674 ).

Food system development pathways for healthy, nature-positive and inclusive food systems

Sustainable food systems require the integration of and alignment between recommendations for food and land use practices, as well as an understanding of the political economy context and identification of entry points for change. We propose a food systems transformation framework that takes these elements into account and links long-term goals with short-term measures and policies, ultimately guiding the decomposition of transformation pathways into concrete steps. Taking the transition to healthier and more sustainable diets as an example, we underscore the centrality of social inclusion to the food systems transformation debate.

Are nudging and pricing strategies on food purchasing behaviors equally effective for all? Secondary analyses from the Supreme Nudge virtual supermarket study

Nudging and pricing strategies are effective in promoting healthier purchases. However, whether the effects are equal across individuals with different personal characteristics is unknown. This exploratory study aimed to examine differential effects of nudging and pricing strategies on food purchases across individuals' levels of impulsivity, price sensitivity, decision-making styles, and food choice motives. Data from a virtual supermarket experiment where participants were exposed to five study conditions (control, nudging, pricing, salient pricing, and salient pricing with nudging) was used. Participants completed questionnaires assessing their impulsivity, price sensitivity, decision-making styles, and food choice motives. The outcome was the percentage of healthy food purchases. Effect modification was analyzed by adding interaction terms to the statistical models and post-hoc probing was conducted for statistically significant interaction terms. We used data from 400 Dutch adult participants (61.3% female, median age 30.0 years (IQR 24.0)). The effects of the nudging and pricing conditions on healthy food purchases were not modified by impulsivity, price sensitivity, decision-making styles, and the food choice motives 'health' and 'price'. Only the interactions of the food choice motive 'natural content of foods' x pricing (B = -1.02, 90%CI = -2.04; -0.01), the food choice motive 'weight control' x nudging (B = -2.15, 90%CI = -3.34; -0.95), and 'weight control' x pricing (B = -1.87, 90%CI = -3.11; -0.62) were statistically significant. Post-hoc probing indicated that nudging and/or pricing strategies were more effective in individuals who gave lower priority to these food choice motives. The effects of nudging and pricing strategies on increasing healthy food purchasing behaviors, at least in a virtual environment, do not seem to be influenced by personal characteristics and may therefore be implemented as general health promoting strategies.