Nudge Interventions Research Articles

The Effect of Nudging in Promoting the Consumption of Organic Fruits and Vegetables.

A field study collecting behavioral data was conducted to investigate effects of behavioral interventions, commonly known as nudges, in promoting the consumption of organic fruits and vegetables. Consumption, both organically and conventionally produced fruits and vegetables, was measured in a grocery store during 4 days (1 day every other week) where consumers were exposed to informational messages in combination with either emotional images or social norm messages. Measurements of daily consumption without exposure to nudges were carried out during four other days (1 day every other week, alternated with the nudging days). The results showed no effect of the nudging strategy; instead, it pointed to the importance of the price as a determinant of buying decisions. Buying ecological alternatives was associated with lower price differences between the ecological and non-ecological alternatives. We conclude that combined nudges and collected psychological data from participants may contribute to more successful nudging interventions. Some political measures in balancing the price difference between organically and conventionally produced products might also be interesting strategies in order to promote the consumption of organic fruits and vegetables.

Behavioral intervention strategies to nudge hand hygiene

<p id="p00005">Maintaining optimal hand hygiene is an important strategy for infection control and prevention. However, how to increase adherence to hand hygiene practices has been a major challenge to prevent infectious diseases and reduce hospital acquired infections (HAIs), especially in the critical period of COVID-19 epidemic regular prevention and control. There are great differences in the effectiveness between different hand hygiene behavior intervention strategies, and the best hand hygiene intervention practice is still in development and requires further investigation. In order to develop intervention strategies for health care researchers and practitioners, the current research systematically summarizes hand hygiene behavior intervention strategies from the perspective of “nudge” for the first time. Traditional hand hygiene interventions are usually based on knowledge sharing and health education, which only produce weak or modest effects on hand hygiene practices. Recent research in behavioral science provides insights for developing effective behavioral interventions to optimize hand hygiene practices by helping people form better hand hygiene habits. Traditional intervention strategies tend to rely on people’s ability to engage in rational thinking and the availability of cognitive resources, that is, encouraging people to reflect on their hand hygiene behaviors and enhance their handwashing motivation in a rational and conscious way. The influences of external environmental factors are rarely taken into account in traditional intervention strategies. Similarly, the role of personal psychological factors is often ignored, so this kind of hand hygiene intervention strategy often shows limited effectiveness and low sustainability. In addition, there are many other common obstacles such as limited accessibility of hand hygiene products, people's overconfidence in their immune system to prevent infection, inertia, and habitual forgetting. Many research results show that even if traditional intervention strategies can increase risk awareness of poor hand hygiene and enhance hand washing intention in the target population, they may not lead to effective behavior changes in hand hygiene. Inspired by the research from behavioral sciences, researchers have tried to promote experiential, unconscious, and automatically triggered hand hygiene behavior through interventions of specific psychological or external environmental factors, so as to help people overcome the gap between hand washing intention and behaviors. Based on different influential mechanisms, hand hygiene nudging strategies can be classified into four categories and nine subordinate categories, including providing decision information (simplifying information, providing feedback, and harvesting the impact of social norms), optimizing decision options (simplifying options and making original options more attractive), influencing decision structure (increasing the accessibility and visibility of favorable options), and reminding decision direction (direct reminder and environmental hint). Previous studies have shown that behavioral science-based hand hygiene interventions, in general, achieved positive effects at a fairly low cost, which are worthy of further application. However, there are still many disputes concerning ethics and effectiveness for nudging intervention. Among these disputes, the two points often mentioned are whether nudging limits the decision-makers' freedom of independent choice and damages their ability of independent choice. These two disputes may have a relatively small impact on hand hygiene promotion, and the form of nudging intervention is more easily accepted by the public, which may be due to the fact that handwashing behavior essentially has a certain degree of “injunctive norm” tendency (i.e., the vast majority of people agree with maintaining hand hygiene). In addition, previous research on hand hygiene nudging intervention also has many limitations, including low accuracy of the evaluation criteria, sustainability, and generalizability of nudging strategies. Further research is warranted to develop more effective hand hygiene nudging interventions and apply them to diverse social contexts. The effectiveness of multi-facet nudging strategies has also been confirmed in hand hygiene practices, suggesting that another future research direction is to construct a hand hygiene nudging strategy classification system similar to the Behavior Change Technique (BCT) taxonomy, so as to design multi-facet nudging strategies for promoting hand hygiene in a specific social context. Based on China's national conditions, traditional hand hygiene intervention strategies such as health education cannot be completely abandoned. This kind of comprehensive new model of “traditional intervention + nudging strategies” and the personalization and specialization of nudging intervention strategies might be the focus of hand hygiene behavior promotion intervention in the future. However, there is still a lack of hand hygiene nudging intervention in Chinese sociocultural contexts. Another direction for future research is to carry out such nudging interventions in hospitals, schools, communities, and other public places based on the theory of behavioral change, so as to contribute to the prevention and control of infectious diseases and improve public health.

Nudging food service users to choose fruit- and vegetable-rich items: Five field studies

Although nudging has been found to promote the choice of healthy foods in lab studies and ad-hoc field studies, relatively little research is available regarding effectiveness in real food venues that operate for profit. The paucity of empirical studies providing “proof of implementation” reveals the difficulty of applying previous empirical findings on nudging to mass-eating food services contexts, which serve meals to a lot of individuals daily. Based on the typology of choice architecture in food choice contexts, we closely collaborated with the in-house food service operator to devise and implement five nudge interventions to promote fruits and vegetables (FV) in university cafeterias. Each study was conducted for one 12-week semester or more over a three-year period. In the first two studies, non-verbal point-of-purchase prompting increased the choice of kale/spinach supplemented smoothies and whole fruits from baskets. In Study 3, the combination of sizing and point-of-purchase non-verbal prompting increased the sale of large size vegetable-rich bowls from a stir-fry grill. In Study 4, the proximity type of nudging by altering the position of the healthier option in a sandwich bar in combination with non-verbal prompting increased the sale of sandwiches containing spinach. In Study 5, the combination of sizing and proximity of large vs. small sized plates and serving spoons had no effect on sale of self-serve items in a salad bar. All the interventions except for Study 5 produced a moderate effect in increasing the choice of FV-rich items. We recommend that hospitality and food service operators consider operational parameters and simultaneously adopt more than one nudging components to achieve a sizable effect. Future randomized controlled trials are needed to implement choice architecture techniques in collaboration with food service companies.

Behavioral Nudges to Improve Audit and Feedback Report Opening Among Antibiotic Prescribers: A Randomized Controlled Trial.

BackgroundPeer comparison audit and feedback has demonstrated effectiveness in improving antibiotic prescribing practices, but only a minority of prescribers view their reports. We rigorously tested 3 behavioral nudging techniques delivered by email to improve report opening.MethodsWe conducted a pragmatic randomized controlled trial among Ontario long-term care prescribers enrolled in an ongoing peer comparison audit and feedback program which includes data on their antibiotic prescribing patterns. Physicians were randomized to 1 of 8 possible sequences of intervention/control allocation to 3 different behavioral email nudges: a social peer comparison nudge (January 2020), a maintenance of professional certification incentive nudge (October 2020), and a prior participation nudge (January 2021). The primary outcome was feedback report opening; the primary analysis pooled the effects of all 3 nudging interventions.ResultsThe trial included 421 physicians caring for >28 000 residents at 450 facilities. In the pooled analysis, physicians opened only 29.6% of intervention and 23.9% of control reports (odds ratio [OR], 1.51 [95% confidence interval {CI}, 1.10–2.07], P = .011); this difference remained significant after accounting for physician characteristics and clustering (adjusted OR [aOR], 1.74 [95% CI, 1.24–2.45], P = .0014). Of individual nudging techniques, the prior participation nudge was associated with a significant increase in report opening (OR, 1.62 [95% CI, 1.06–2.47], P = .026; aOR, 2.16 [95% CI, 1.33–3.50], P = .0018). In the pooled analysis, nudges were also associated with accessing more report pages (aOR, 1.28 [95% CI, 1.14–1.43], P < .001).ConclusionsEnhanced nudging strategies modestly improved report opening, but more work is needed to optimize physician engagement with audit and feedback.Clinical Trials RegistrationNCT04187742.

Lowering the harm of tourist activities: a systematic literature review on nudges

Tourists harm the destination environment in many different ways. Behavioural economics contributes to the formulation of public and private policies to reduce this harm. The nudging agenda is converging with tourism, where managers and policymakers realise that the implementation of nudges leads to lower costs, higher effectiveness of behavioural changes, and decreased harm produced by tourists. However, little effort has been made to comprehend the relationship between nudges and tourism sustainability. To fill this gap, this paper systematises the literature on nudge interventions in tourism and sustainability studies. Our results present the main disciplinary background in these investigations with Anglo-Saxon countries leading research on green nudges. The methodological approach adopted by the nudge studies is limited, and causal evidence is lacking. The thematic analysis categorises the interventions and supports the idea that nudges target both unconscious and conscious behaviours. The preferred interventions are those with a low-cost application, such as bed linen reuse. Social norms are the main trigger for developing hypotheses and designing nudges. Our study also presents the mediators and moderators of pro-environmental behaviours and develops a model to design nudges in the tourism industry. Theoretical, managerial contributions and suggestions for future studies are also discussed.

A Systematic Review of Nudge Interventions to Optimize Medication Prescribing.

Background: The benefits of medication optimization are largely uncontroversial but difficult to achieve. Behavior change interventions aiming to optimize prescriber medication-related decisions, which do not forbid any option and that do not significantly change financial incentives, offer a promising way forward. These interventions are often referred to as nudges. Objective: The current systematic literature review characterizes published studies describing nudge interventions to optimize medication prescribing by the behavioral determinants they intend to influence and the techniques they apply. Methods: Four databases were searched (MEDLINE, Embase, PsychINFO, and CINAHL) to identify studies with nudge-type interventions aiming to optimize prescribing decisions. To describe the behavioral determinants that interventionists aimed to influence, data were extracted according to the Theoretical Domains Framework (TDF). To describe intervention techniques applied, data were extracted according to the Behavior Change Techniques (BCT) Taxonomy version 1 and MINDSPACE. Next, the recommended TDF-BCT mappings were used to appraise whether each intervention applied a sufficient array of techniques to influence all identified behavioral determinants. Results: The current review located 15 studies comprised of 20 interventions. Of the 20 interventions, 16 interventions (80%) were effective. The behavior change techniques most often applied involved prompts (n = 13). The MINDSPACE contextual influencer most often applied involved defaults (n = 10). According to the recommended TDF-BCT mappings, only two interventions applied a sufficient array of behavior change techniques to address the behavioral determinants the interventionists aimed to influence. Conclusion: The fact that so many interventions successfully changed prescriber behavior encourages the development of future behavior change interventions to optimize prescribing without mandates or financial incentives. The current review encourages interventionists to understand the behavioral determinants they are trying to affect, before the selection and application of techniques to change prescribing behaviors. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42020168006].

Nudges for more sustainable food choices in the out-of-home catering sector applied in real-world labs

Food production is responsible for approximately 17% of Germany's greenhouse gas (GHG) emissions. After retail, out-of-home catering is the second largest food sales channel in Germany. A variety of means on both the supply and demand side are necessary to stimulate, facilitate and encourage a more sustainable development and minimise GHG emissions in this sector. Nudges are one of these. This paper's focus lies on the demand side. Set in real-world laboratories, we use a standardised empirical approach to compare different nudging interventions belonging to the area of physical environment and consumers’ choice making process. We compare the effects of the same intervention across different settings and the effect of different, sequential nudging interventions in the same setting. Data was collected in eight workplace and school cafeterias in Germany over two project iterations (2016/2017; 2019/2020). A similar intervention design was applied. Comparability was assured by a harmonised menu. The first project iteration revealed that only one nudge (top menu position, +22.5%) led to significant increases in sustainable food choices, while results from the second iteration showed that all nudge interventions (best counter position, +11.6%; top menu position, +6,9%; label plus information, +15.9%) positively influenced consumer choice. Possible explanations such as the stricter compliance to the experimental design in the cafeterias but also societal developments such as the appearance of the Fridays for Future movement are discussed. As results vary between specific locations and settings, our findings suggest that nudges need to be adjusted to situational conditions for achieving highest efficacy.

RCTs to Scale: Comprehensive Evidence From Two Nudge Units

Nudge interventions have quickly expanded from academic studies to larger implementation in so‐called Nudge Units in governments. This provides an opportunity to compare interventions in research studies, versus at scale. We assemble a unique data set of 126 RCTs covering 23 million individuals, including all trials run by two of the largest Nudge Units in the United States. We compare these trials to a sample of nudge trials in academic journals from two recent meta‐analyses. In the Academic Journals papers, the average impact of a nudge is very large—an 8.7 percentage point take‐up effect, which is a 33.4% increase over the average control. In the Nudge Units sample, the average impact is still sizable and highly statistically significant, but smaller at 1.4 percentage points, an 8.0% increase. We document three dimensions which can account for the difference between these two estimates: (i) statistical power of the trials; (ii) characteristics of the interventions, such as topic area and behavioral channel; and (iii) selective publication. A meta‐analysis model incorporating these dimensions indicates that selective publication in the Academic Journals sample, exacerbated by low statistical power, explains about 70 percent of the difference in effect sizes between the two samples. Different nudge characteristics account for most of the residual difference.

Nudging consumers towards energy efficiency through behavioural science: Profiling of energy consumers across Europe

Reducing energy consumption to increase energy efficiency and mitigate climate change demands drastic behavioural changes. Accordingly, the European Horizon 2020 founded project called “NUDging consumers towards enerGy Efficiency through behavioral science” (NUDGE) aims is to analyze the behavior of European citizens with concern the energy consumption and to consequently design and test nudging interventions on different segments of the population. Since recent studies have identified ways to influence behaviour through nudging interventions that, without limiting people’s options, can support their behavioural choices in a predictable manner, the NUDGE project – coordinated by the Institute for European Energy and Climate Policy Stitching (IEECP) – is set up to analyse people’s behaviour with concern to energy consumption, and to design and test nudging interventions in households, energy communities, and schools in five EU Member States (Greece, Belgium, Germany, Portugal and Croatia). All interventions are rooted in fundamental principles of behavioural science and based on the results of a general profiling survey that has been disseminated online across Europe from March to June 2021. The survey permitted to assess energy consumers’ attitudes and to consequently profile users into groups based on their behaviour, which allows used to carry out targeted interventions and assess their impact. Such comprehensive approach will be used to derive recommendations tailored to each country and to design more general policies at European level.

Different Shades of Nudges: Moderating Effects of Individual Characteristics and States on the Effectiveness of Nudges during a Fast-Food Order

Nudges, or subtle changes to a choice environment, are increasingly used in online food ordering platforms to improve dietary choices and reduce calorie intake. We report the results of an experiment aimed at nudging young adults to reduce calories in a fast-food order (N = 994). The nudging interventions used were: an order assistant, a color-coded system, and a combination of the order assistant and color-coded system. We hypothesized that participants’ characteristics (sex, BMI, education) and states (positive affect, negative affect, hunger) moderate the effectiveness of nudges. Our analysis shows that the effect of nudges is slightly increasing at higher BMI levels. In the combined treatment, hunger and negative affect significantly moderate the effect of nudges. We do not observe the moderating effects of participants’ sex, educational level, and positive affect in any of the treatments.

Reducing antibiotic prescribing using nudges: A systematic review of interventions in primary care

Introduction: Inappropriate antibiotic use in primary care is high. Nudge interventions, from the field of behavioural economics, are an approach to behaviour change that has been making significant inroads in healthcare. We conducted a systematic review to assess the effect of nudge interventions to reduce inappropriate antibiotic prescribing in primary care.

Nudge strategies for behavior-based prevention and control of neglected tropical diseases: A scoping review and ethical assessment.

Nudging, a strategy that uses subtle stimuli to direct people's behavior, has recently been included as an effective and low-cost behavior change strategy in low- and middle- income countries (LMIC), targeting behavior-based prevention and control of neglected tropical diseases (NTDs). The present scoping review aims to provide a timely overview of how nudge interventions have been applied within this field. In addition, the review proposes a framework for the ethical consideration of nudges for NTD prevention and control, or more broadly global health promotion. A comprehensive search was performed in several databases: MEDLINE, PsycINFO, and Embase (Ovid), Web of Science Core Collection, CINAHL, ERIC and Econ.Lit (EBSCO), as well as registered trials and reviews in CENTRAL and PROSPERO to identify ongoing or unpublished studies. Additionally, studies were included through a handpicked search on websites of governmental nudge units and global health or development organizations. This scoping review identified 33 relevant studies, with only two studies targeting NTDs in particular, resulting in a total of 67 nudge strategies. Most nudges targeted handwashing behavior and were focused on general health practices rather than targeting a specific disease. The most common nudge strategies were those targeting decision assistance, such as facilitating commitment and reminder actions. The majority of nudges were of moderate to high ethical standards, with the highest standards being those that had the most immediate and significant health benefits, and those implemented by agents in a trust relationship with the target audience. Three key recommendations should inform research investigating nudge strategies in global health promotion in general. Firstly, future efforts should investigate the different opportunities that nudges present for targeting NTDs in particular, rather than relying solely on integrated health promotion approaches. Secondly, to apply robust study designs including rigorous process and impact evaluation which allow for a better understanding of 'what works' and 'how it works'. Finally, to consider the ethical implications of implementing nudge strategies, specifically in LMIC.

Can nudging only get you so far? Testing for nudge combination effects

Abstract There is an emerging body of evidence to suggest that nudges can motivate behaviour change. The question as to whether using nudges in tandem ‘crowds out’ the marginal effectiveness of each one has attracted little attention. Using a randomised survey experiment consisting of 1,800 farmers, we tested the impact of two nudge interventions (injunctive norm and social signalling) when used individually in isolation and also when used in combination. Our findings are indicative of limited crowd out effects and more generally suggest that there may be scope for employing non-monetary interventions in combination when it comes to encouraging technology uptake.

The effectiveness of nudging interventions to promote healthy eating choices: A systematic review and an intervention among Italian university students

Nudges are changes in choice architecture (i.e., the environment in which people make decisions) aiming to steer a person's decision to a particular choice, without restricting alternative options or changing financial incentives. These strategies have been extensively used to promote healthy eating, above all among youths, whose behaviors can still be easily shaped compared to older people's. The current paper describes two studies aiming to investigate the effectiveness of nudging interventions in promoting healthy eating among university students. The first study consisted of a systematic review mapping all the published studies which describe the effectiveness of this kind of intervention worldwide. Twelve eligible records were selected after a search of three different databases. Information about the publication of the record, the adopted research methods and the described intervention was retrieved from each selected record. Based on this review's results, a new nudging intervention was developed to promote healthy food choice among Italian university students. The intervention aimed to modify students' choice for each of the Italian meal courses: first course (pasta, rice or soup), second course (meat, fish, cheese or cured meat), side dish, bread, and fruit. An Italian university cafeteria was observed in two phases: a pre-intervention phase (baseline) and a post-intervention phase (nudging strategies were implemented in the cafeteria's architecture).The applied nudging intervention was effective in promoting healthy choices in relation to the second course, the side dish, and the bread, but it did not significantly affect choices related to the first course or the fruit. Implications of these results and suggestions for future interventions are discussed.

Privacy nudges for disclosure of personal information: A systematic literature review and meta-analysis.

Digital nudging has been mooted as a tool to alter user privacy behavior. However, empirical studies on digital nudging have yielded divergent results: while some studies found nudging to be highly effective, other studies found no such effects. Furthermore, previous studies employed a wide range of digital nudges, making it difficult to discern the effectiveness of digital nudging. To address these issues, we performed a systematic review of empirical studies on digital nudging and information disclosure as a specific privacy behavior. The search was conducted in five digital libraries and databases: Scopus, Google Scholar, ACM Digital Library, Web of Science, and Science Direct for peer-reviewed papers published in English after 2006, examining the effects of various nudging strategies on disclosure of personal information online. The review unveiled 78 papers that employed four categories of nudge interventions: presentation, information, defaults, and incentives, either individually or in combination. A meta-analysis on a subset of papers with available data (n = 54) revealed a significant small-to-medium sized effect of the nudge interventions on disclosure (Hedges' g = 0.32). There was significant variation in the effectiveness of nudging (I2 = 89%), which was partially accounted for by interventions to increase disclosure being more effective than interventions to reduce disclosure. No evidence was found for differences in the effectiveness of nudging with presentation, information, defaults, and incentives interventions. Identifying ways to nudge users into making more informed and desirable privacy decisions is of significant practical and policy value. There is a growing interest in digital privacy nudges for disclosure of personal information, with most empirical papers focusing on nudging with presentation. Further research is needed to elucidate the relative effectiveness of different intervention strategies and how nudges can confound one another.

Post-Secondary Food Service Manager Perspectives on Fruit and Vegetable Nudging Strategies: Qualitative Study.

ABSTRACTBackgroundChanging the choice architecture in post-secondary food service contexts to “nudge” customers to choose more fruits and vegetables (FV) shows promise in intervention studies to date. If such approaches are to become more widely adopted, they must be feasible and acceptable to food service managers. Among possible early adopters, managers of food services in post-secondary education institutions may have unique insights on implementation of such approaches, as they have dual mandates to support student health and maintain profitability.ObjectiveThe goal of this exploratory study was to examine current knowledge, practice, facilitators, and barriers to uptake of nudge strategies promoting FV in a sample of post-secondary food service managers.MethodsA qualitative telephone interview study was undertaken with food service managers across Canada (n = 10 institutions), recruited from a national professional organization. One or more representatives from each institution completed the interview. Interviews were audio-recorded, transcribed, and underwent framework descriptive and interpretative content analysis in NVivo (QSR International). Münscher's Taxonomy of Choice Architecture and the Ottawa Model for Research Use guided development and analysis.ResultsManagers from 9 universities and 1 technical college participated. Local context, governance, and resources varied widely. Eight of 10 institutions used some form of FV nudging as part of their marketing and health promotion, most commonly to reduce the effort associated with choosing FV. Nudging strategies aimed at increasing the range and composition of FV offerings, providing a social reference (opinion leaders) for choosing FV, and changing consequences with loyalty cards were also common. Other nudging strategies were used infrequently. Cost, operational ease of implementation, and students’ privacy and choices were critical issues in adoption.ConclusionsThe results can inform development and testing of locally adapted nudge interventions. It is critical that managers be involved from the outset of any planned academic implementation study.

Nudging interventions on sustainable food consumption: a systematic review

As population growth continues, sustainable food behaviour is essential to help reduce the anthropogenic modification of natural systems, driven by food production and consumption, resulting in environmental and health burdens and impacts. Nudging, a behavioural concept, has potential implications for tackling these issues, encouraging change in individuals’ intentions and decision-making via indirect proposition and reinforcement; however, lack of empirical evidence for effectiveness and the controversial framework for ethical analysis create challenges. This systematic review evaluated the effectiveness of nudging interventions on sustainable food choices, searching five databases to identify the effectiveness of such interventions. Of the 742 identified articles, 14 articles met the eligibility criteria and were included in this review. Overall, the potential of certain nudging interventions for encouraging sustainable food choices were found in strategies that targeted ‘system 1’ thinking (automatic, intuitive and non-conscious, relying on heuristics, mental shortcuts and biases), producing outcomes which were more statistically significant compared to interventions requiring consumer deliberation. Gender, sensory influences, and attractiveness of target dishes were highlighted as pivotal factors in sustainable food choice, hence research that considers these factors in conjunction with nudging interventions is required.

Equity Effects of Dietary Nudging Field Experiments: Systematic Review

Background: Dietary behaviours are among the key modifiable risk factors for non-communicable diseases. Importantly, dietary behaviours vary substantially between groups and individuals with different socioeconomic positions, with more disadvantaged groups and individuals being exposed to more dietary risk factors. The goal of this review is to summarise the existing research on equity effects of dietary nudging interventions.Methods: Systematic review of nudging interventions conducted in a field setting that report an observable indicator of dietary behaviour, include a control group, and report effect sizes stratified by indicators of socioeconomic status as outlined in the PROGRESS-Plus framework. Two databases (scopus, Pubmed) were searched (last search June 2021), and 18 articles with 19 studies (k = 46 equity comparisons) were included. Risk of bias was assessed using the ROBINS-I tool. Due to heterogeneity in equity dimensions and study outcomes, a harvest plot was used to summarise data.Results: The majority of equity comparisons (38 out of 46) were available for cognitive nudges. Most of these (22 out of 38 comparisons) found that cognitive nudges worked equally well in more and less disadvantaged populations; however, in 12 out of the 38 comparisons, they favoured those who were less disadvantaged. Two out of four comparisons on behavioural nudges favoured more disadvantaged persons.Conclusions: The differential effects of dietary nudging interventions in this review can contribute to increases in health inequalities. At the same time, a substantial number of interventions showed no equity effects. Importantly, this review suggests that more research on nudging interventions and health equity is needed. Future interventions should report effect sizes stratified by indicators of social inequality.Systematic Review Registration: PROSPERO (CRD42019137469)

Determinants of Food Choice and Perceptions of Supermarket-Based Nudging Interventions among Adults with Low Socioeconomic Position: The SUPREME NUDGE Project.

Nudging has received ample attention in scientific literature as an environmental strategy to promote healthy diets, and may be effective for reaching populations with low socioeconomic position (SEP). Therefore, the objective of this study was to investigate how the determinants of food choice shape the perceptions regarding supermarket-based nudging strategies among adults with low SEP. We conducted semi-structured interviews among fifteen adults with low SEP using a pre-defined topic list and visual examples of nudges. Interviews were recorded and transcribed verbatim and content analysis was used to analyse the data. The results show that food costs, convenience, healthiness, taste, and habits were frequently mentioned as determinants of food choice. However, the relative importance of these determinants seemed to be context-dependent. Interviewees generally had a positive attitude towards nudges, especially when they were aligned with product preferences, information needs, and beliefs about the food environment. Still, some interviewees also expressed distrust towards nudging strategies, suspecting ulterior motives. We conclude that nudging strategies should target foods which align with product preferences and information needs. However, the suspicion of ulterior motives highlights an important concern which should be considered when implementing supermarket-based nudging strategies.

Eating in the Amazon: Nutritional Status of the Riverine Populations and Possible Nudge Interventions.

The Amazon is the largest tropical forest in the world and a source of healthy food, such as fruits and fish. Surprisingly, the Amazonian riverine population present an increased prevalence (as high as 58%) of non-communicable diseases, such as hypertension and insulin resistance, even higher than that described for the urban population of the Amazon. Therefore, this work aimed to analyze the nutritional status and associated risk of the riverine population. Body mass index, waist circumference (WC), waist-to-hip ratio, and neck circumference (NC) were evaluated, and risk analysis was assayed. Furthermore, data about occupation and the prevalence of consumers of the different groups of food were analyzed. All anthropometric parameters revealed high proportions of individuals at risk, WC and NC being the factors that had more high-risk women and men, respectively. Our data confirmed the characteristic profile of the riverine communities with a high number of fish consumers, but also observed different patterns probably associated to a phenomenon of nutrition transition. Based on our data, some nudge interventions that take into account the principles of behavior analysis are discussed and proposed for these populations, aiming to improve the nutritional status and avoid the long-term consequences of the results showed by this work.