Healthy Food Purchases Research Articles

Healthy food purchase intention: The moderation effect of intuitive thinking and perceived knowledge

This paper aims to study the relationships among intuitive thinking, nutritional information, perceived knowledge, subjective norm, trust, and health concerns on purchase intention. The study was conducted with 461 consumers in Brazil. Structure Equation Modeling (SEM) was applied. Most of our hypotheses were supported and demonstrated that consumers with high perceived knowledge care less about social influence. On the other hand, when it comes to using nutritional information to develop trust in food producers, consumers rely more on intuitive thinking. Trust and health consciousness have a positive effect on purchase intention. Policymakers can benefit from the results to develop accurate public policies, and food manufacturers can use them to adequate resolutions and implement labels with consumers’ well-being under perspective. We confirmed that if consumers perceive that they have sufficient knowledge and can make their decisions mostly based on it, less they will rely on subjective norms.

Baltimore community resident and collaborator perspectives on the influence of guaranteed income on health: a formative qualitative study

BackgroundGiven increased interest and investment in guaranteed income initiatives across North America, it is critical to understand the impact of guaranteed income on health, an understudied outcome. As part of Baltimore, Maryland’s guaranteed income pilot, we conducted formative research to understand the influence of increased income on health and develop concrete recommendations for implementation and evaluation of the pilot.MethodsWe conducted semi-structured in-depth interviews with Baltimore community residents (n = 8) and community collaborators (n = 8), probing on familiarity with guaranteed income; effect of guaranteed income on overall health and specific health outcomes (e.g., mental health, nutrition); and recommendations for program structure (e.g., eligibility, target population). Data were analyzed thematically using a framework analysis approach.ResultsRespondents agreed that guaranteed income could have beneficial effects on health though some were unsure of specific mechanisms. Respondents emphasized pathways through which guaranteed income could improve health: (1) reduced financial-related stress; (2) improved nutrition through purchase of healthier foods; (3) improved family well-being including child health and parent-child relationships; (4) increased utilization of health services; (5) improved community health through increased community cohesion and decreased violence. Respondents described decreased feelings of time scarcity as a social determinant of health. Most respondents reported that Baltimore’s guaranteed income program should prioritize young, low-income families with $1,000/month or more for at least one year.ConclusionsThis formative research on the potential health impacts of guaranteed income in Baltimore highlights important health outcomes and pathways, such as social cohesion and decreased feelings of time scarcity, to prioritize for evaluation.

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

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

Grocery Delivery to Support Individuals With Type 2 Diabetes: Protocol for a Pilot Quality Improvement Program.

People with low income are disproportionately affected by type 2 diabetes (T2D), and 17.6% of US adults with T2D experience food insecurity and low diet quality. Low-carbohydrate eating plans can improve glycemic control, promote weight loss, and are associated with improved cardiometabolic health and all-cause mortality. Little is known about supporting low-carbohydrate eating for people with T2D, although food-as-medicine interventions paired with nutrition education offer a promising solution. This program aims to support the initiation of dietary changes by using grocery delivery and low-carbohydrate education to increase the quality of low-carbohydrate nutrition among people with T2D and food insecurity. This program was a nonrandomized pilot conducted at 21 primary care practices in Michigan. Adults with T2D and food insecurity or low income were eligible to enroll. Patients were referred by primary care clinic staff. All participants received the 3-month program, which included monthly US $80 credits for healthy foods, free grocery delivery from Shipt, and low-carbohydrate nutrition education. Food credits were restricted to the purchase of healthy foods. Education materials, developed in collaboration with providers and patients, included print, digital, interactive web, and video formats. At enrollment, participants completed a survey including demographics, diabetes health, diet and physical activity, and diabetes management and knowledge. After the 3-month program, participants completed a survey with repeat assessments of diabetes health, diet and physical activity, and diabetes management and knowledge. Perspectives on participant experience and perceived program impact, food purchasing behaviors, and use of educational materials were also collected. Diabetes health information was supplemented with data from participant medical records. We plan to perform mixed methods analysis to assess program feasibility, acceptability, and impact. Primary quality improvement (QI) measures are the number of patients referred and enrolled, use of US $80 food credits, analysis of food purchasing behavior, participant experience with the program, and program costs. Secondary QI measures include changes in hemoglobin A1c, weight, medications, self-efficacy, diabetes and carbohydrate knowledge, and activity between baseline and follow-up. This program started in October 2022. Data collection is expected to be concluded in June 2024. A total of 151 patients were referred to the program, and 83 (55%) were enrolled. The average age was 57 (SD 13; range 18-86) years, 72% (57/79) were female, 90% (70/78) were White, and 96% (74/77) were of non-Hispanic ethnicity. All participants successfully ordered grocery delivery during the program. This pilot QI program aimed to improve diet quality among people with T2D and food insecurity by using grocery delivery and low-carbohydrate nutrition education. Our findings may help inform the implementation of future QI programs and research studies on food-as-medicine interventions that include grocery delivery and education for people with T2D. DERR1-10.2196/54043.

Fruitful changes? Exploring household fruit purchase decisions following comprehensive food policy regulations in Chile

Changes in unprocessed healthy food purchases associated with the implementation of comprehensive food policy remain understudied. This study analyzes whether, following the announcement, modification, and implementation of Chile's Food Labeling and Advertising law targeting highly processed food (occurring in 2012, 2015, and 2016, respectively), households improved their fruit purchase decisions: purchase participation (i.e., buying likelihood) and purchase quantity. Expenditure data from a representative sample of Chilean households were employed, covering two consecutive survey waves conducted in 2011/2012 and 2016/2017. After controlling for socioeconomic factors (e.g., prices and income), results indicate that only purchase participation increased, providing weak support for positive spillover effects of a comprehensive food policy on fruit purchases. Subsample analyses reveal that this increase was driven by college-educated, childless, and low-income households and was stronger for sweeter and more convenient fruits. Considering that households in Chile do not meet health recommendations for daily fruit intake, additional policy efforts targeting healthy, unprocessed food consumption could be considered.

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.

Abstract P483: Food Purchase Priorities and Healthy Food Purchase Supports and Barriers for U.S. General and Low-Income Consumers: A Quantitative Survey

Introduction: Identifying priorities and attributes that influence food purchase decisions will inform interventions and strategies to promote healthy eating. Aim: This study aimed to identify food purchase priorities and healthy food purchase supports and barriers for the general population and those with limited household income. Methods: Participants were recruited by a market research company in May 2023 and were required to be ≥ 18 years old, not work in healthcare/medical/nutrition or advertising/public relations/marketing/market research and be the primary/shared food decision maker for the household. Recruitment quotas ensured age, income, gender and geographic region approximated 2022 US census data (n=1,182) (Census-representative group, CRG). A sample with limited income and participation in federal food or healthcare programs (low-income group, LIG) was also recruited (n=506). The survey was administered online in May and June 2023. Differences between LIG and CRG were assessed using z-tests (p < 0.05). Results: Taste was most commonly rated by CRG as very or extremely important in household food purchasing (87%). Availability, price, ingredients and nutritional value were also important to at least two-thirds of CRG. Taste was similarly important to LIG (85%), but they were more likely to rate price and less likely to rate availability, nutritional value and ingredients as important. When prompted to choose the most important factor, price and taste were the most common responses, chosen by similar proportions of CRG, while price was the most important factor for LIG, followed by taste. CRG versus LIG were more likely to prioritize personal taste over cost, health and nutrition information on labels, buying local and selecting according to nutrition, brand and origin/sourcing information. CRG were less likely than LIG to prefer a lower cost and usually select according to price. LIG were more likely than CRG to state that nothing supports them in selecting healthier foods and less likely to have found support from good-tasting recipes, advance meal or grocery list preparation, cooking equipment access, following influencers, recommendations from organizations or consulting a dietitian/nutritionist. Conversely, LIG were more likely to identify price and availability as barriers to selecting healthier foods, and less likely to see long preparation time, small servings sizes or nothing as barriers. Conclusions: Cost is a strong barrier to healthy eating, especially with limited income, along with taste, while nutrition is not a leading influence on food choice. Strategies to enable healthy eating among low-income households must prioritize taste and cost.

The dynamics in food selection stemming from price awareness and perceived income adequacy: a cross-sectional study using 1-year loyalty card data

BackgroundHigher cost of healthy foods may explain unhealthy dietary patterns in lower-income households. Unfortunately, combining food selection and nutrient intake data to price and expenditure is challenging. Food retailer’s customer loyalty card data, linked to nutrient composition database, is a novel method for simultaneous exploration of food purchases, price, and nutrition. ObjectivesWe studied the associations between perceived income adequacy (PIA) as a grouping variable with price (per kilogram or megajoule) and the volume of purchases (percentage of expenditure or energy) simultaneously as outcome variables for 17 most purchased food groups. MethodsWe used 1-year (2018) loyalty card data from the largest grocery chain in Finland. Participants were 28,783 loyalty cardholders who made ≥41% of food purchases from the retailer and answered an online questionnaire at the midpoint of data collection. The 5-level PIA described the perceived financial situation in the household. Energy and nutrient content of foods purchased were from the Finnish Food Composition Database Fineli. We calculated the Nutrient Rich Food Index per 100 g food using 11 nutrients. Trends in prices and expenditures between PIA levels were analyzed using 2-sided Jonckheere–Terpstra tests, with false discovery rate control (Benjamini–Hochberg method) and confounder adjustments (inverse probability weighting). ResultsLower PIA participants selected cheaper foods per kilogram and megajoule within most food groups. They also favored unhealthy food groups cheap in energy [<1 € (USD 1.18)/MJ]. Despite lower purchase price, the expenditure (%) among lower PIA was higher on alcohol, snacks, sugar-sweetened beverages, and sweets and chocolates. ConclusionsParticipants with lower PIA showed stronger price awareness. It is crucial to consider the pricing of competing alternative food groups, when steering toward environmentally sustainable and healthier food purchases. Package labeling might also direct the selection of healthier choices among the less expensive items within a food group.

Toward an Integrated Model of Healthy Food Purchase via the Impact of Online Nutrition Information Seeking

Healthy eating is critical to consumers’ overall health. The purpose of this study was to examine body mass index (BMI), obesity knowledge, and self-efficacy, along with online nutrition information seeking (ONIS), as antecedents to healthy food purchase (HFP) in a moderated mediation model. An online survey was conducted using Amazon Mechanical Turk to recruit 897 participants, with 484 women and 380 men. A moderated mediation analysis was then used to explore the mediating effect of ONIS, and the moderating effects of obesity knowledge and self-efficacy. Results found the impact of ONIS on HFP was significantly generated by obesity knowledge but not by BMI. Both ONIS and self-efficacy yielded individual and interactive effects on HFP, and ONIS did not only generate a direct effect on HFP but also interacted with self-efficacy for HFP. Practically, it was suggested that online health information should be strategically crafted to promote healthy eating behavior, given that consumers in various health conditions were activated to purchase heathier foods via ONIS. Through the ONIS’s mediation of the relationship between obesity knowledge and HFP, consumers with poor obesity knowledge would be cultivated well to further develop their better eating habits.

Understanding family food purchasing behaviour of low-income urban UK families: An analysis of parent capability, opportunity and motivation

ObjectiveFamily food purchasing decisions have a direct influence on children's food environments and are powerful predictors of obesity and dietary quality. This study explored parents' capability, opportunities, and motivations regarding food purchasing for their families, as well as barriers and facilitators of healthy food purchasing behaviour, in an ethnically diverse, low-income area. DesignSemi-structured interviews with parents of under-11-year-old children were conducted to investigate family food purchases, both when eating inside and outside the home. Interviews were analysed using framework analysis mapped against the COM-B model (Michie et al., 2011). SettingAn ethnically diverse, low-income area in Birmingham, UK. ParticipantsSixteen parents (13F, 3M) of under-11-year-old children. 75% Pakistani, 12.5% White British, 6.3% White and Black Caribbean, and 6.3% “Other”. ResultsFour themes were identified: i) I know how to provide healthy meals for my family, ii) Family food purchase decisions are complex, iii) I want what they are eating and iv) Healthy eating is important but eating outside of the home is a treat. The barriers of healthy family food purchasing were predominantly at family and community levels, including time, cost, and both parents' and children's food enjoyment and preferences. Facilitators of healthy family food purchasing were primarily identified at an individual level, with high levels of capability and motivation for healthy food provision. ConclusionsAttempts to enhance parental capability to improve healthy food purchasing through nutrition education is not likely to be a useful intervention target in this group. Emphasis on enjoyment, palatability and value for money could be key to increasing parental motivation to purchase healthy family foods.

A Review of Research on Factors Influencing Chinese Consumers' Healthy Food Purchases

The public's health awareness has increased substantially with the progress of society, food safety incidents are frequent, and the Chinese government has introduced a number of health-related policies, so it is necessary to study the influencing factors on consumers' purchasing of healthy food. This paper investigates the influencing factors on consumers’ purchase of healthy food through literature analysis and finds that consumers’ perception of healthy food significantly influences their purchase of healthy food through different dimensions. Perceptions are correlated with education, however, when consumers perceive that the health food market in China is not sufficiently safe and secure the higher their level of concern the lower their purchase rate. Purchasing habits and preferences, income level, type of occupation, and personal and family health conditions all have an impact on the purchase of healthy foods. Among product factors high prices are a major barrier to healthy food purchases. Government regulation of the food industry and consumer protection all have a strong effect on consumer purchases of healthy food. Characteristics such as the environment, convenience, trustworthiness and price level of the place of consumption also have an impact on the purchase of health food.

A systematic review of the implementation of healthy food retail interventions in settings with multiple food retail outlets (complex food retail settings).

Complex food retail settings, where multiple food retail outlets operate in close proximity are common. Despite their ubiquity, there remains a significant knowledge gap regarding healthy food retail interventions implemented within these settings. Furthermore, understanding the factors affecting the implementation of interventions in these settings remains limited. This systematic review aimed to (1) identify and describe complex food retail settings where interventions were implemented to promote the healthiness of foods purchased, (2) synthesise the evidence on the effectiveness of the interventions implemented, and (3) identify enablers and barriers to the implementation of the interventions in these settings. Four databases, namely, MEDLINE Complete, Global Health, Embase, and Business Source Complete, were searched until December 2022. The Effective Public Health Practice Project quality assessment tool was used. Six studies reported on the implementation of interventions promoting healthy food purchases across multiple food retail outlets. Three studies each described two complex food retail settings: university and hospital. Interventions including promotion and promotion plus price improved the healthiness of foods purchased. There was limited description of institutional food policies, conceptual frameworks, formative research, or evaluation outcomes to inform the implementation of interventions in these settings. No study analysed enablers and barriers to the implementation of interventions. No study identified their settings as complex food retail settings. There is limited evidence describing complex food retail settings, their impact on intervention effectiveness, and associated enablers or barriers. Investigating factors influencing the effectiveness of interventions implemented within complex food retail settings is critical to support their implementation at scale.

Designing and analyzing the motivational risk profile of healthy food and agricultural products purchase

Several factors influence consumer preferences for food and agriculture. Knowing and evaluating these factors is necessary to promote the purchase and consumption of healthy products and correct nutritional behaviors. This study aims to identify and evaluate the risks that consumers face when buying healthy products. For this purpose, the sources of risk were displayed in a matrix, and the factors influencing the motivational risk of buying these products were investigated using the generalized ordinal logit method. The sample size in this study is 359 households that live in Mashhad- Iran, and the information on the samples is collected from an online questionnaire. The results of the risk matrix show that worrying about the low level of household income is the highest risk score, and low trust in the advice of others has the lowest score. Variables of age, education, nutritional knowledge, special diet, importance to product health, and presence of children under five years old in the household have positive effects on the risk. Variables of household expenses and government supervision have a negative effect. Suggestions like reforming the production and processing system of nutrition and agriculture in order to supply healthy, cheap, and accessible products, improving the level of nutrition and public awareness about the risks of not consuming healthy products are also made to reduce barriers to healthy nutrition.

Digital Influencers Promoting Healthy Food: The Role of Source Credibility and Consumer Attitudes and Involvement on Purchase Intention

This article investigates the influence of digital influencers on healthy food purchase intention within the context of Instagram. The research model is guided by the theory of source credibility and the elaboration likelihood model. A quantitative approach was employed, and data were collected through an online survey from Instagram users in Portugal (n = 221). A set of ten hypotheses was tested using structural equation modeling (SPSS-AMOS). The findings corroborated that purchase intention of healthy foods is positively influenced by digital influencer perceived credibility, involvement with healthy foods, and attitude toward advertising on Instagram. The findings also confirmed that involvement with healthy foods and with Instagram affect advertising avoidance behavior, and that these three constructs affect attitude toward advertising on Instagram. However, the expected relationship between attitude toward advertising and digital influencer credibility was not confirmed. The study contributes to the literature on influencer marketing, specifically in the context of healthy food, and it provides valuable insights for social media marketers and brand managers interested in adopting influencer marketing to leverage their communication effectiveness.

P22-035-23 Targeted Messaging Techniques to Encourage Healthy Food Purchasing: A Proposed Study Protocol

P22-035-23 Targeted Messaging Techniques to Encourage Healthy Food Purchasing: A Proposed Study Protocol

Australians support for policy initiatives addressing unhealthy diet: a population-based study.

To inform public health policy implementation in Australia, our study investigated the level of public support for six policy initiatives addressing unhealthy diet. The policy initiatives included taxing soft drinks and energy drinks, taxing less healthy food and beverage purchases, zoning to restrict the supply of junk foods near schools, prohibiting advertising and promotion of less healthy food and beverages to children under the age of 16 and restricting sugar-sweetened beverages from vending machines in schools, and public places. Data from a cross-sectional population-based study for 4040 Australians aged 15+ years, were analysed. A high overall support across all policy initiatives was observed. Nearly three-quarter of public support was observed for policy initiatives targeting children (zoning to restrict the supply of junk food near schools, prohibiting advertising and promotion of less healthy food and beverages to children under the age of 16 and restricting sugars-sweetened beverages from vending machines in schools), and half of Australians supported policy initiatives of taxing soft drinks and energy drinks and taxing less healthy food and beverage purchases. Australian women and those with tertiary level of education were more likely to support public health initiatives targeting children and all policy initiatives respectively. Interestingly, young adults expressed low level of support for all policy initiatives. The study demonstrated considerable public support for policy initiatives focussed on protecting children from unhealthy diet in Australia. Framing, designing and implementing policies targeting children is potentially a good starting point for policymakers to create a health promoting food environment.

Which Front-of-Package Nutrition Label Is Better? The Influence of Front-of-Package Nutrition Label Type on Consumers' Healthy Food Purchase Behavior.

To help consumers understand the healthfulness of food and make healthy food choices, manufacturers are increasingly providing front-of-package nutrition labels. However, not all types of front-of-package nutrition labels can promote consumers' healthy food purchase behavior. We explored the impact of front-of-package nutrition label type on the consumer purchase behavior of healthy food through three experiments. The results show that evaluative (vs. objective) front-of-package nutrition labels can improve consumer purchase intention and willingness to pay for healthy food. The spokesperson type moderates the influence of front-of-package nutrition labels on consumers' healthy food purchase behavior. Specifically, when the spokesperson type is a typical consumer, consumers are more willing to buy healthy foods with evaluative nutrition labels than those with objective nutrition labels. When the spokesperson type is a star, consumers are more willing to buy healthy food with objective nutrition labels (vs. evaluative nutrition labels). Finally, this study provides feasible suggestions for marketers to select appropriate front-of-package nutrition labels.

Policy Opportunities and Legal Considerations to Reform SNAP-Authorized Food Retail Environments.

There is an invigorated national interest in nutrition security, with emphasis on the Supplemental Nutrition Assistance Program (SNAP) playing a key role. To support healthy food purchasing, several strategies have emerged to modify the food retail environment. However, the legal feasibility of several such policy options has not been established. Research was conducted using Lexis+ to evaluate statutes, regulations, and case law to determine the legal feasibility of requiring retail-based SNAP signage and nutrition disclosures, healthy endcaps and checkout aisles, and tying advertising restrictions to the licensing of SNAP retailers. US in-store and online food retail retailers. Legal feasibility. Requiring retailers that designate certain foods or locations as SNAP-eligible to consistently do so in all SNAP-eligible pages/locations is likely feasible. If properly drafted to focus on the nutritional quality of food, healthy checkout and endcap restrictions are legally feasible. It is of unclear legal feasibility to require retailers (especially in-store) to disclose nutrition-related labeling, shelf tags, or nonfactual symbols indicating the relative healthfulness of products. Restricting or banning advertising is not legally feasible even if the government ties the restrictions to retail licensing requirements. Entities seeking to support healthy food retail should not seek to restrict advertising or compel retailers to convey messages against their interests. The government can license retailers and require them to abide by laws and other requirements that do not violate their constitutional rights. The government can also use its own speech through public service announcements, billboards, and transit advertising to encourage healthy food consumption for all shoppers including those who use SNAP. Additional research is warranted into online retail practices to evaluate variations in online checkout pages and to determine whether online retailers treat SNAP participants differently from non-SNAP participants.

The Role of Children in the Family Purchase Decision-Making Process About Healthy Versus Unhealthy Food

This study explores how children are involved in the family decision-making process when buying healthy vs unhealthy food, and whether this involvement is influenced by family emotional climate. Participants are 239 parents of 7 to 13 years old children. They completed a set of self-report questionnaire related to healthy and unhealthy foods perception; consumer purchase decision making process; children's influences strategies in food purchase; influence exerted by children in the food purchasing process; family cohesion, flexibility, and communication. The results highlight how the children used influence strategies and became more involved in consumer purchasing decisions when they come to unhealthy food than healthy food. The emotional family climate also modifies both the frequency of use and the level of participation in the consumer purchase decision making process. This study provides insight into the key predictors of the development of certain consumption skills in children and how they use them to influence the family purchase of healthy and unhealthy foods.

Abstract 53: Real-Life Effects of Nudging and Pricing Strategies in the Supermarket to Promote Healthy Diets and Cardiometabolic Health: The Supreme Nudge Parallel Cluster-Randomized Controlled Trial

Introduction: Unhealthy food intake is a major risk factor for cardiometabolic diseases. Individual-level efforts to promote heathy diets (e.g., nutrition education) have limited effect on the long term. Designing the choice context in such a way that it facilitates healthy food choices may contribute to sustainable prevention of cardiometabolic diseases. We evaluated the real-life effects of nudging and pricing strategies in supermarkets. Hypothesis: Exposure to store-level nudging and pricing will improve dietary guideline adherence, healthy food purchasing and customer satisfaction, and reduce cardiometabolic risk among Dutch adults after 12 months compared to no intervention. Methods: In this parallel cluster-randomized controlled trial, we randomized 12 Dutch supermarkets in socially disadvantaged neighborhoods to a control (n=6 supermarkets) or intervention group (n=6). Intervention supermarkets received healthy food nudges (across 13 food groups on circa 9% of supermarket products) and pricing strategies (price decreases on healthy products and increases on unhealthy products; on circa 3% of products). Eligible participants were aged 30-80 years and regular shoppers at participating supermarkets. The primary outcome was dietary guideline adherence measured via a validated index score (scale 0-150), at baseline and after 3, 6 and 12 months. Secondary outcomes included the percentage of healthy food purchases, parameters of cardiometabolic health (HbA1c (mmol/L), lipid profile (mmol/L), and waist circumference (cm)), and supermarket customer satisfaction (very unsatisfied (1) to very satisfied (7)). Implementation fidelity was regularly monitored (no implementation (1) to optimal implementation (5)). Results: Of the 361 participants included (162 intervention, 199 control), 73% were female, 42% were highly educated and the average age (sd) was 58 (11) years. Linear mixed models showed no effectiveness of the intervention compared to control on dietary guideline adherence (β -1.1, 95%CI: -3.8; 1.7), the total percentage of healthy purchases (β 0.4, 95%CI: -3.0; 3.7), HbA1c (β 0.6, 95%CI: -0.1; 1.3), lipid profile (LDL β -0.0, 95%CI: -0.2; 0.1, HDL β -0.0, 95%CI: -0.1; 0.0), and waist circumference (females β 0.7 (95%CI: -0.8; 2.2), males β 0.5, 95%CI: -2.4; 3.5) over the 12-month intervention period. Participants in the intervention clusters scored 0.3 points (95%CI: 0.1; 0.5) higher on overall customer satisfaction, compared to control clusters. Median implementation fidelity over time was 3.6 (range 2.9-4.1). Conclusions: Nudging and pricing strategies implemented in a real-life purchasing setting were not effective in promoting healthier diets and purchasing patterns nor in improving cardiometabolic health on an individual level. Sub-optimal intervention exposure due to practical implementation barriers may have contributed to these null results.