Nudging towards sustainable dining: Exploring menu nudges to promote vegetarian meal choices in restaurants.

Food choice behavior plays a large role in achieving sustainability goals. Meat in particular has a negative environmental impact as compared with plant-based food - and is more frequently chosen in restaurant contexts. To increase plant-based meal choices in restaurants, we tested three nudges for menus that are likely to be implemented by restaurant owners: a hedonic label (e.g., artisanal vegetable burger), a chef's recommendation (specifying the vegetarian option as the chef's favorite), and a salience nudge (a box around the vegetarian option). In an online experiment, we showed participants (n = 513) in four conditions (no nudge, hedonic label, chef's recommendation, and salience nudge) five menus with four meal options each, one of which was vegetarian. We asked participants to choose a meal and subsequently to rate these meals on how tasty and indulgent they were (taste and indulgence attributions). We then revealed which nudge was used to the participants and asked how participants received it. Results show that the hedonic label and chef's recommendation nudge (but not the salience nudge) both increase vegetarian meal choices. The hedonic label increased participants' attributions of indulgence of the meal, but not of tastiness. This finding fits with restaurants' gastronomic, pleasure-seeking context and shapes future directions of labeling interventions, namely that indulgence attributions can be increased in vegetarian foods. Furthermore, the nudges were generally well accepted and participants' intention to return to the (virtual) restaurant was high. Finally, customers expected the hedonic label nudge to be more effective in promoting vegetarian food choices than the other two nudges, partially corresponding with our findings of actual effectiveness.

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 (ߠ- 1.1 (95% CI - 3.8 to 1.7)), percentage healthy purchasing (ß 0.7 ( - 2.7 to 4.0)), step count (ߠ- 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 (ß - 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.

The role of attention and health goals in nudging healthy food choice.

Introduction: Nudging is a promising intervention technique that supports people in pursuing their healthy eating goals. Recent research suggests that, despite previous assumptions, disclosure of the presence of a nudge does not compromise nudge effectiveness. However, it is unknown whether attention to a nudge affects nudge effects. We assessed the role of attention systematically, by examining explicit and implicit attention to nudges, while also exploring healthy eating goals as a potential moderator. Methods: Participants were assigned to a nudge (i.e., a shopping basket inlay with pictures of healthy items) or control condition (i.e., a shopping basket inlay with neutral pictures) and chose a snack in an experimental supermarket field study. Explicit and implicit attention (with a mobile eye-tracker) to nudges, healthiness of snack choice, and healthy eating goals were assessed. Results: Results showed that attention to the nudge did not hamper the nudge's effect. Furthermore, individuals with strong healthy eating goals made healthier food choices in the nudge condition. Individuals with weak to non-existent healthy eating goals were not influenced by the nudge. Discussion: Findings are in line with the viewpoint that nudging does not by definition work 'in the dark', and suggests that nudges support people in adhering to their healthy eating goal.

Mental models of the protein shift: Exploring consumers' perceptions of the transition.

The protein transition is one of today's major societal challenges to mitigate climate change. To support lasting consumer engagement, it has been suggested to look into consumers' understanding of the protein transition to identify barriers that go beyond the practical issues of changing one's diet. The current study explored consumers' mental models of how the transition unfolds to examine which factors consumers perceive as important drivers of the transition. With a fixed set of factors and actors identified with a questionnaire, Dutch consumers (N = 214) mapped their mental models. The content and structure of the mental models were analyzed with a focus on how consumers perceive their own role. Animal well-being and environmental concerns were most often included as important drivers. The findings showed a lack of consensus about which actor(s) drive the transition (i.e., none of the actors were included by a majority of the participants). This diffusion of responsibility may be a barrier for consumers to act. Moreover, the relative simplicity of the observed mental models suggests that consumers do not yet employ systems thinking. A systems thinking mindset may help consumers understand how the system behind the transition works and how their individual contributions matter. Two avenues to encourage consumer engagement were identified: 1) emphasizing the responsibility of different actors and what consumers can contribute, and 2) encouraging a systems thinking mindset.

Understanding public support for COVID-19 pandemic mitigation measures over time: Does it wear out?

Background: COVID-19 mitigation measures intend to protect public health, but their adverse psychological, social, and economic effects weaken public support. Less favorable trade-offs may especially weaken support for more restrictive measures. Support for mitigation measures may also differ between population subgroups who experience different benefits and costs, and decrease over time, a phenomenon termed "pandemic fatigue." Methods: We examined self-reported support for COVID-19 mitigation measures in the Netherlands over 12 consecutives waves of data collection between April 2020 and May 2021 in an open population cohort study. Participants were recruited through community panels of the 25 regional public health services, and through links to the online surveys advertised on social media. The 54,010 unique participants in the cohort study on average participated in 4 waves of data collection. Most participants were female (65%), middle-aged [57% (40-69 years)], highly educated (57%), not living alone (84%), residing in an urban area (60%), and born in the Netherlands (95%). Results: COVID-19 mitigation measures implemented in the Netherlands remained generally well-supported over time [all scores >3 on 5-point scale ranging 1 (low)-5 (high)]. During the whole period studied, support was highest for personal hygiene measures, quarantine and wearing face masks, high but somewhat lower for not shaking hands, testing and self-isolation, and restricting social contacts, and lowest for limiting visitors at home, and not traveling abroad. Women and higher educated people were more supportive of some mitigation measures than men and lower educated people. Older people were more supportive of more restrictive measures than younger people, and support for more socially restrictive measures decreased most over time in higher educated people or in younger people. Conclusions: This study found no support for pandemic fatigue in terms of a gradual decline in support for all mitigation measures in the first year of the pandemic. Rather, findings suggest that support for mitigation measures reflects a balancing of benefits and cost, which may change over time, and differ between measures and population subgroups.

Personal values, motives, and healthy and sustainable food choices: Examining differences between home meals and restaurant meals.

People are increasingly eating out in restaurants, where meals tend to be higher in calories, less nutritious, and contain more meat. In this paper, we argue that differences in the motivational processes underlying people's food choices could help to explain why food choices made in restaurants are typically unhealthier and less sustainable than at home. Using online survey data from 301 Dutch participants, we compared the influence of stable personal values and transient food choice motives on the healthiness and sustainability of meals chosen in a hypothetical choice task, which was geared to the home and restaurant consumption contexts. As expected, participants opted for unhealthy and meat-based meals more often in the restaurant than the home context. Conservation values related negatively and self-transcendence values positively to choosing sustainable meals both in the home and in the restaurant context, although the relation with self-transcendence values was significantly weaker in the restaurant context. Also, taste and social eating were considered more important for choosing restaurant meals, while health was a more important motive for food choices at home. Finally, model comparisons revealed that motives were better predictors of healthy meal choices in both contexts, while the influence of values and motives on sustainable meal choices was more similar. In conclusion, the results from the present study enhance our understanding of differences between choosing home and restaurant meals by providing an account of the values and motives associated with the healthiness and sustainability of home and restaurant meal choices.

Snacking for a reason: detangling effects of socio-economic position and stress on snacking behaviour.

BACKGROUND: As snacking can be considered a cornerstone of an unhealthy diet, investigating psychological drivers of snacking behaviour is urgent, and therefore the purpose of this study. Socio-economic position (SEP) and stress are known to affect many behaviours and outcomes, and were therefore focal points in the study. METHODS: In a cross-sectional survey study, we examined whether Socio-economic position (SEP) would amplify associations between heightened stress levels and self-reported negative-affect related reasons for snacking. Next, we investigated whether Socio-economic position (SEP) predicted frequency of snacking behaviour, and how stress and other reasons for snacking could explain this association. Outcome measures were reasons people indicated for snacking, and frequency of snacking behaviour. RESULTS: Analyses revealed that people seem to find more reasons to snack when they are stressed, and that this association was more pronounced for people with a high compared to low socio-economic position. Furthermore, a higher socio-economic position was associated with a higher frequency of snacking, and both snacking to reward oneself and snacking because of the opportunity to do so remained significant mediators. CONCLUSION: Whereas low socio-economic position was associated with higher stress levels, this did not translate into increased snacking. Contrarily, those with higher socio-economic position could be more prone to using 'reasons to snack', which may result in justification of unhealthy snacking behaviour.

How do people understand the spread of COVID-19 infections? Mapping mental models of factors contributing to the pandemic.

OBJECTIVE: To describe the mental models people hold about the COVID-19 pandemic, with a focus on how they understand the factors that drive the spread of COVID-19 and what kind of beliefs are associated with these models. DESIGN: In a series of three studies (total N = 461), we asked participants to identify factors that are relevant for COVID-19 proliferation (Study 1a), rate the importance of factors (Study 1 b), and create a mental model of how these factors relate to virus spread by employing a validated tool for mental model elicitation (Study 2). Main outcome measures: inclusion and centrality of factors in mental models of COVID-19 infection spread. RESULTS: Mitigation measures issued by government, adherence to measures, and virus characteristics were most strongly represented in participants' mental models. Participants who perceived measures as appropriate or who experienced more control and more worry over the spread of the virus created more complex models compared to participants who were less satisfied with measures or who felt lower control and less worry. CONCLUSION: These findings suggest that people are able to create sensible mental models of virus transmission but may appreciate transparent communication to comprehend the bigger picture behind the governmental mitigation strategy.

Can we have a second helping? A preregistered direct replication study on the neurobiological mechanisms underlying self-control.

Self-control is of vital importance for human wellbeing. Hare et al. (2009) were among the first to provide empirical evidence on the neural correlates of self-control. This seminal study profoundly impacted theory and empirical work across multiple fields. To solidify the empirical evidence supporting self-control theory, we conducted a preregistered replication of this work. Further, we tested the robustness of the findings across analytic strategies. Participants underwent functional magnetic resonance imaging while rating 50 food items on healthiness and tastiness and making choices about food consumption. We closely replicated the original analysis pipeline and supplemented it with additional exploratory analyses to follow-up on unexpected findings and to test the sensitivity of results to key analytical choices. Our replication data provide support for the notion that decisions are associated with a value signal in ventromedial prefrontal cortex (vmPFC), which integrates relevant choice attributes to inform a final decision. We found that vmPFC activity was correlated with goal values regardless of the amount of self-control and it correlated with both taste and health in self-controllers but only taste in non-self-controllers. We did not find strong support for the hypothesized role of left dorsolateral prefrontal cortex (dlPFC) in self-control. The absence of statistically significant group differences in dlPFC activity during successful self-control in our sample contrasts with the notion that dlPFC involvement is required in order to effectively integrate longer-term goals into subjective value judgments. Exploratory analyses highlight the sensitivity of results (in terms of effect size) to the analytical strategy, for instance, concerning the approach to region-of-interest analysis.

Make it a habit: how habit strength, goal importance and self-control predict hand washing behaviour over time during the COVID-19 pandemic.

OBJECTIVE: Hand washing has been at the core of recommendations and guidelines that aim to curb infectious diseases in general, and COVID-19 in particular. As hand washing comes down to an individual's behaviour, we aimed to study how individual psychological variables influence hand washing over time during the COVID-19 pandemic. DESIGN: Over the course of 20 weeks, participants answered questions about their hand washing behaviour, goal importance, habit strength and self-control. Participants from an experimental and a control condition completed a baseline and final measurement, and the experimental condition was invited to bi-weekly measurements through reminders. MAIN OUTCOME MEASURE: Hand washing behaviour over the past 14 days was assessed by self-report at baseline and final measurement, and additionally repeatedly over the course of 20 weeks in the experimental condition. RESULTS: Hand washing behaviour decreased over time, but this decrease was buffered by habit strength and goal importance. The decrease was smaller in the experimental condition that received reminders every 2 weeks. CONCLUSION: Sending personal reminders on hand washing behaviour contributes to hand washing behaviour. Moreover, taking habit strength and goal importance, and to a lesser extent self-control into account is important when designing interventions to promote hand washing behaviour.

Who accepts nudges? nudge acceptability from a self-regulation perspective.

BACKGROUND: Public acceptability of nudging is receiving increasingly more attention, but studies remain limited to evaluations of aspects of the nudge itself or (inferred intentions) of the nudger. Yet, it is important to investigate which individuals are likely to accept nudges, as those who are supposed to benefit from the implementation should not oppose it. The main objective of this study was to integrate research on self-regulation and nudging, and to examine acceptability of nudges as a function of self-regulation capacity and motivation. METHOD: Participants (N = 301) filled in questionnaires about several components of self-regulation capacity (self-control, proactive coping competence, self-efficacy, perceived control and perceived difficulty) and motivation (autonomous motivation and controlled motivation). To evaluate nudge acceptability, we used three vignettes describing three types of nudges (default, portion size, and rearrangement) that stimulated either a pro-self behavior (healthy eating) or pro-social behavior (sustainable eating) and asked participants to rate the nudges on (aspects of) acceptability. RESULTS: Results revealed that there were substantial differences in acceptability between the three types of nudges, such that the default nudge was seen as less acceptable and the rearrangement nudge as most acceptable. The behavior that was stimulated did not affect acceptability, even though the nudges that targeted healthy eating were seen as more pro-self than the nudges targeting sustainable eating. From all self-regulation components, autonomous motivation was the only measure that was consistently associated with nudge acceptability across the three nudges. For self-regulatory capacity, only some elements were occasionally related to acceptability for some nudges. CONCLUSION: The current study thus shows that people are more inclined to accept nudges that target behaviors that they are autonomously motivated for, while people do not meaningfully base their judgments of acceptability on self-regulatory capacity.

The effect of nudges on autonomy in hypothetical and real life settings.

Nudges have repeatedly been found to be effective, however they are claimed to harm autonomy, and it has been found that laypeople expect this too. To test whether these expectations translate to actual harm to experienced autonomy, three online studies were conducted. The paradigm used in all studies was that participants were asked to voluntarily participate in a longer version of the questionnaire. This was either done in a hypothetical setting, where participants imagined they were asked this question, but did not answer it, and reported their expectations for autonomy; Or in an actual choice setting where participants answered the question and then reported their actual autonomy. The first study utilized the hypothetical setting and tried to replicate that laypeople expect nudges to harm autonomy with the current paradigm. A total of 451 participants were randomly assigned to either a control, a default nudge, or a social norm nudge condition. In the default nudge condition, the affirmative answer was pre-selected, and in the social norm nudge condition it was stated that most people answered affirmative. The results showed a trend for lower expected autonomy in nudge conditions, but did not find significant evidence. In Study 2, with a sample size of 454, the same design was used in an actual choice setting. Only the default nudge was found to be effective, and no difference in autonomy was found. In Study 3, Studies 1 and 2 were replicated. Explanation of the nudge was added as an independent variable and the social norm nudge condition was dropped, resulting in six conditions and 1322 participants. The results showed that participants indeed expected default nudges to harm their autonomy, but only if the nudge was explained. When actually nudged, no effect on autonomy was found, independent of the presence of an explanation.

Discussing overweight in dogs during a regular consultation in general practice in the Netherlands.

In previous studies, it has been demonstrated that, similar to general practitioners, veterinarians find it difficult to discuss overweight in dogs. This study aimed to provide insight in the barriers and motivators for veterinarians to discuss overweight in dogs and to compare the results with findings from human medicine. Sub-hypotheses were postulated based on existing literature to investigate if lack of time, fear of offending clients, or lack of skills were potential barriers, and if feeling responsible and feeling compassion were potential motivators for veterinarians to discuss overweight in dogs. To this end, an online survey (n = 59) was conducted. Furthermore, 15 small animal clinicians working in general practice were interviewed by semi-structured face-to-face interviews. Results from the online survey indicated that veterinarians find it sometimes difficult to discuss overweight in dogs. Veterinarians who responded to the online survey did not experience strong barriers but did make use of motivators (e.g. feeling responsible and feeling compassion) when discussing overweight in dogs. Interestingly, results from the semi-structured face-to-face interviews showed that the responding veterinarians did experience strong barriers, as well as motivators, when discussing overweight in dogs with their clients. The most prominent barrier was customer dissatisfaction, whereas lack of time and lack of skills were also experienced. The most prominent motivator was feeling responsible for animal health and preventive veterinary medicine. These findings were strikingly similar to previous research on discussing childhood overweight by general practitioners. To improve treatment and prevention of overweight in dogs, veterinarians need more communication skills and should be more aware of the motivators that drive their self-motivation. Improving awareness on overweight and its comorbidities should be a One Health issue.

Evaluating the Potential Benefit of a Combined Weight Loss Program in Dogs and Their Owners.

Introduction: Little has been published on the psychological bond between the owner and the pet, and how this might influence shared habits that could lead to overweight and obesity. Another factor that could improve the effectiveness of a weight loss plan, is that the owner would see the dog as a weight loss partner and therefore this could increase the motivation to follow the assigned diet and exercise guidelines. Objective: The aim of this research was to evaluate the potential mutual effects of weight loss programs for both dogs and dog owners. Methods: Two studies were conducted: In the human-centered trial, 60 dog owners were enrolled, who signed up to receive dietary and exercise recommendations to lose weight themselves during an 8 week period, from which 29 were randomly assigned to also get recommendations for their dog. For the dog-centered trial, we selected 13 dog owners that wanted their dog to lose weight during a 6 week period, from which 7 were randomly assigned to also get recommendations for themselves. The average weight loss over the time period was recorded. A questionnaire was used to evaluate diet and exercise habits, as well as information about the relationship between the dog and owner. Results: The average human weight loss was 2.6% in the owner+dog group (n = 29) and 2.3% in the owner only group (n = 31; p > 0.05). Forty percent (24/60) of the dogs in the human-centered trial were overweight. The overweight dogs in the owner+dog group (n = 12/29) lost 3.7% of their body weight, compared to 1.2% in the overweight dogs from the owner only group (n = 12/31; p > 0.05). In the dog-centered trial, the 7 dogs in the dog+owner group lost 8.0% of their body weight, vs. 8.3% in the six dogs in the dog only group (p > 0.05). The owners in the dog+owner group lost 2.5% of their body weight, compared to 0.5% in the dog only group (p > 0.05). In both trials owners' perceived responsibility for both their own and their dogs' weight significantly increased. In addition, habit strength regarding unhealthy feeding and exercise behaviors in relation to the dogs decreased, and self-efficacy in relation to providing the dog with healthy food and exercise increased. Conclusion: Active weight loss in either dog owner or dog, seemed to lead to passive weight loss in the other, especially when some tools or guidelines were provided. These findings support mutual benefits of weight loss programs for dogs and dog owners, and support future weight loss programs to be a One Health approach.

Under pressure: Nudging increases healthy food choice in a virtual reality supermarket, irrespective of system 1 reasoning.

Previous research has shown that nudging can effectively support people's healthy food choices. Yet, to date knowledge about the psychological premises of nudging is limited, highlighting the need for closer scrutiny to determine how and when nudging is most effective. In the current study, we assessed whether the presumed effect of nudging on healthy food choice is enhanced under time pressure, a condition probing alleged system 1 reasoning. Food choice was studied in a realistic virtual reality supermarket where healthier alternatives were nudged by making them more salient. We additionally explored possible differences in decision-making experiences related to nudging or time pressure. The study took place at a science festival where visitors could decide to participate in a study. Participants (n = 99) had to purchase four products, each from a different product category that was provided on a shopping list. In the nudging condition, one healthier option within each product category was nudged by making it more salient. While a main effect of nudging was found, showing in increased healthy food choices, this effect was not further qualified by time pressure, suggesting that the effectiveness of nudging is not enhanced under system 1 conditions. Relatedly, people who were and who were not aware of the nudges showed similar effects of nudging on healthy food choice. Furthermore, no differences in decision-making experiences showed, suggesting that people have similar experiences regarding impulsive and reflective decision-making irrespective of whether they are being nudged or put under time pressure. All in all, our findings are in line with recent viewpoints on the premises of nudges, suggesting that alleged system 1 conditions are not a prerequisite for nudging to be effective.

And How Would That Make You Feel? How People Expect Nudges to Influence Their Sense of Autonomy.

OBJECTIVE: While nudges are increasingly utilized in public policy settings, their potential threat to autonomous choice is the topic of heated debate. Regardless of the actual effects of nudges on autonomy, the mere perception of nudges as autonomy threatening by the general public or policy makers could negatively influence nudge acceptability. The present online studies examined how people expect (different) nudges to affect their perception of autonomy. METHODS: In the first study (N = 455), participants were presented with a hypothetical choice that employed either a default nudge, direct persuasion, or no persuasion, to steer to the desired choice. The presented influence technique was explained before participants reported their expected autonomy, as well as their expected choice satisfaction. Study 2 (N = 601) involved a replication of Study 1 with an additional social norm nudge condition. In Study 3 (N = 750), the explanation of how choice had been influenced was omitted. RESULTS: While participants expected the default nudge to violate autonomy (Study 1), they had no such expectations for social norm nudges (Study 2). Omitting the explanation that most people are unaware of nudges influencing their choice, reduced the negative impact of nudges on expected autonomy (Study 3). CONCLUSION: Effects of nudges on expectations of autonomy differ by type of nudge. Negative expectations are primarily driven by the explanation that decision makers are often unaware of nudges.

When in Doubt, Follow the Crowd? Responsiveness to Social Proof Nudges in the Absence of Clear Preferences.

Nudges have gained popularity as a behavioral change tool that aims to facilitate the selection of the sensible choice option by altering the way choice options are presented. Although nudges are designed to facilitate these choices without interfering with people's prior preferences, both the relation between individuals' prior preferences and nudge effectiveness, as well as the notion that nudges 'facilitate' decision-making have received little empirical scrutiny. Two studies examine the hypothesis that a social proof nudge is particularly effective when people have no clear prior preference, either because people are indifferent (in a color-categorization task; Study 1, N = 255) or because people experience a choice conflict (making shopping decisions about meat products; Study 2, N = 97). Both studies employed a social proof nudge to steer participants' choices. The potential facilitating effect of the nudge was tested using a mouse-tracker paradigm that implicitly assessed experienced uncertainty during decision-making. Results showed that the nudge was effective in steering participants' decisions; the facilitation effect (i.e., reduced uncertainty regarding the decision) was only observed for conflicting preferences, but not under indifference. A better understanding of when and how nudges can influence individuals' behavior may help in deciding whether nudges are an appropriate policy tool for changing particular undesirable behavior.

Beyond Discrete Choices - Investigating the Effectiveness of a Proximity Nudge With Multiple Alternative Options.

Nudges are defined as small adjustments in the choice architecture that stimulate desirable behavior. Nudging techniques can be used as a promising policy tool, but research has hardly systematically taken into account the complexity of the situation in which nudges have been implemented. In the current studies, we investigated the effectiveness of a proximity nudge on food choice in a realistic situation with multiple options in the immediate surroundings of the target option. In two studies, we presented participants from a community sample with an assortment of either three or nine different types of chocolate. For half of the participants, the target chocolate was placed most proximally on a table. Across two studies, we demonstrated that the proximity nudge was effective in stimulating the choice for a specific piece of chocolate in a simple and more complex situation. Results were further qualified by Bayesian analyses, which revealed most support for the hypothesis that the proximity effect existed in both the conditions with three and nine options, regardless of the number of options in the choice set. Results imply that the proximity effect can remain robust in realistic situations that include multiple options in the immediate environment to choose from.

The (bitter) sweet taste of nudge effectiveness: The role of habits in a portion size nudge, a proof of concept study.

Seemingly insignificant daily practices, such as sugar usage in tea, can have a great accumulated impact on societal issues, such as obesity. That is why these behaviours are often the target of nudge interventions. However, when these behaviours are performed frequently they may turn into habits that are difficult to change. The aim of the current study was to investigate whether a portion size nudge has the potential to work in accordance with (instead of against) existing habits. Specifically, it was tested whether a portion size nudge would be more effective in reducing the amount of sugar added to tea, when people have a strong habit of adding a fixed amount of teaspoons of sugar to a cup of tea. The study (N = 123) had a mixed factorial design with teaspoon size (reduced size vs. control) as a within-subject factor, and habit disruption context condition (hot tea vs. cold tea) as a between-subjects factor. A paired t-test indicated that this nudge reduced sugar intake on average by 27% within subjects. When the context allowed for automatic enactment of the habit, the effectiveness of this nudge was moderated by habit strength. Surprisingly, the nudge effect was actually less pronounced when people had a strong habit. Implications for effective nudge interventions are discussed.

Discussing overweight in children during a regular consultation in general practice: a qualitative study.

BACKGROUND: Overweight in children is a rising problem leading to serious consequences later in life. The Dutch guideline 'Obesity' for general practitioners recommends discussing obesity in children regardless of the reason of consultation and provides diagnostic and therapeutic tools. However, limited literature indicates that general practitioners experience barriers to discuss this topic. The aim of this study was to determine current perceived barriers of general practitioners in discussing overweight during a regular consultation in children aged 4 to 12 years and to what extent they discuss the topic. Furthermore, we attempt to get more insight in the specific needs and ideas for improvement among GPs. METHODS: A semi-structured in-depth interview study was conducted. Dutch general practitioners with a broad range of demographic characteristics were invited to participate. The transcripts were analysed using a modified version of the constant comparative method. Using this method, we identified perceived barriers of general practitioners. RESULTS: Ten general practitioners were included in the study. Four major themes were identified in the interviews: absence of physical or mental complaints related to overweight, internal barriers of the general practitioners, the child's family background and logistics. Major barriers appeared to be a low consultation rate of these children, the sensitivity of the topic (e.g. fear for children's or parents' reactions and/or disturbance of the relation, influence on the self-esteem of the child, resistance in the parents), the absence of a long-standing relation between general practitioner and child or parent, the background of the child and lack of time or prioritizing. CONCLUSION: Dutch general practitioners indicate to experience barriers and need tools for how to discuss children's overweight during regular consultations within the limited time available. The low consultation rate among children aged 4 to 12 years due to lack of physical complaints is mentioned as a new and important barrier. Therefore, the prior focus might be raising awareness among parents concerning overweight in children aged 4 to 12 years and, thereby, stressing the potential supporting role of primary care professionals in tackling the overweight of their child.