Offering within-category food swaps to reduce energy density of food purchases: a study using an experimental online supermarket

Online retail nudges to help parents with lower-income choose healthy beverages for their children: A randomized clinical trial

BACKGROUND

Nudges offer a promising tool to reduce sugary drink intake among children who are most at risk for diet-related disease.

OBJECTIVE

To examine the impact of online store nudges on purchases of sugary drinks for children in lower-income households.

METHODS

Caregivers with lower-income were recruited to an online shopping experiment and instructed to spend $10-$30 on three beverages for their child aged 1-5 years. Participants were randomized to navigate an online supermarket in its standard version (n = 1106) or a version with nudges (n = 1135), including a product placement nudge (i.e. placing healthy beverages in prominent positions) and a swap nudge (i.e. offering a swap of water, plain milk and/or 100% fruit juice upon selection of sugary drinks).

RESULTS

On average, participants purchased 1887 (SD = 2113) and 620 (SD = 1528) calories from sugary drinks per basket in the control and experimental conditions, respectively. Model-based results indicate that those in the experimental condition purchased 1267 (95% CI: 1419, 1114) fewer calories from sugary drinks, and fewer grams of total sugar (β = -253.5 g (95% CI: -286.3, -220.6)) and added sugar (β = -287.8 g (95% CI: -323.1, -252.5)) purchased from sugary drinks.

CONCLUSION

Nudges may be an effective, acceptable, scalable strategy for leading caregivers in lower-income households to purchase fewer sugary drinks for their children.

Protocol: The effects of nutrient- vs food- vs food-substitution-based dietary recommendations for reducing free sugar intakes, on free sugar intakes, dietary profiles and sweet taste outcomes: A randomised controlled trial

BACKGROUND

Dietary guidelines are intended to inform and aid the general public, with the aim of improving healthy diets and reducing health risk. The effectiveness of these guidelines, however, is rarely investigated.

AIM

This work investigates the effects of three different types of dietary recommendations for reducing free sugars, on free sugar intakes over 12 weeks. Secondary aims will also investigate how these different recommendations affect secondary outcomes, outcomes in subsets of the trial population, and identify barriers and facilitators to dietary change.

METHODS

Using a randomised controlled parallel-group trial with three intervention and one control arms, 240 individuals consuming >5% total energy intake from free sugars will be randomized to receive: nutrient-based, nutrient- and food-based, nutrient-, food- and food-substitution-based recommendations or no recommendations, with outcomes assessed for the following 12 weeks. Our primary outcomes are free sugar intakes and adherence to the recommendations. Secondary outcomes are daily energy intake, dietary composition, anthropometry, sweet food perceptions and preferences, sweet food choice, attitudes towards sweet foods, eating behaviour and food choice, knowledge and lifestyle variables, quality of life, adverse events, and barriers and facilitators towards intervention adherence.

RESULTS

Data will contribute to three distinct analyses: 1) Analyses to investigate the effects of the three different dietary recommendations versus control; 2) Analyses of the effects of the dietary recommendations in different population subgroups, and 3) Investigation of the barriers and facilitators to success.

CONCLUSION

This work offers new perspectives on the effects of different dietary recommendations to enact behaviour change.

'Healthier options tend to get lost in the noise of online' - Australian shoppers' experiences with online grocery platforms

OBJECTIVE

We aimed to understand what influences parents' purchasing behaviours when shopping for groceries online and potential ways to improve the healthiness of online grocery platforms.

DESIGN

We conducted semi-structured interviews, guided by the Marketing Mix framework. Reflexive thematic analysis was used to analyse data.

SETTING

Online interviews were conducted with primary grocery shoppers.

PARTICIPANTS

Parents (n 14) or caregivers (n 2) using online grocery platforms at least every 2 weeks.

RESULTS

Most participants perceived purchasing healthy food when shopping for groceries online to be more challenging compared to in physical stores. They expressed concerns about the prominence of online marketing for unhealthy food. Participants from lower socio-economic backgrounds often depended on online supermarket catalogues to find price promotions, but healthy options at discounted prices were limited. Across socio-economic groups, fresh items like meat and fruit were preferred to be purchased instore due to concerns about online food quality.Participants believed online grocery platforms should make healthy foods more affordable and supported regulations on supermarket retailers to promote healthy options and limit unhealthy food promotion online.

CONCLUSIONS

Participants had varied experiences with online grocery shopping, with both positive and negative aspects. Efforts to improve population diets need to include mechanisms to create health-enabling online grocery retail platforms. Government interventions to restrict marketing of unhealthy foods and promote marketing of healthy options on these platforms warrant investigation.

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

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

Impact of food swap recommendations on dietary choices in an online supermarket: A randomized controlled trial

One novel strategy to shift food choices in digital shopping environments is to automatically recommend healthier alternatives when an unhealthy choice is made. However, this raises the question which alternative products to recommend. This study assesses 1) whether healthier food swap recommendations are effective, even though the unhealthy choice was made in the presence of visible FOP nutrition labels, and 2) how the similarity of the alternatives influences the acceptance of food swap recommendations. Based on a pre-test, similarity of the recommendation was operationalized in terms of animal-based versus plant-based options. A randomized controlled trial (healthy food swap recommendation conditions: none, similar animal-based, dissimilar plant-based, or mixed animal- and plant-based) with 428 Dutch participants was conducted in a simulated online supermarket. Additional healthier food swap recommendations improved the nutritional quality of the final basket compared to only providing Nutri-Score nutrition labels (-1.7 mean FSA score, p < .001, medium Cohen's d = -0.48). Compared to the dissimilar condition, acceptance of an alternative was more likely in the mixed (odds-ratio = 2.78, p = .015) and in the similar condition (odds-ratio = 2.24, p = .048), but the nutritional quality of the final basket did not differ between treatment conditions. Individuals in treatment conditions who did not receive any recommendation (i.e. only made healthy choices) had higher Nutri-Score familiarity and general health interest than individuals who received recommendations. This suggests that for individuals with higher knowledge and motivation FOP nutrition labels were sufficient, whereas for individuals with lower knowledge and motivation additional food swap recommendations can improve dietary choices. Food swap recommendations may act as meaningful reminders by disrupting the automatic choice process and triggering individuals to rethink their (unhealthy) choice.

Changing the default order of food items in an online grocery store may nudge healthier food choices

Restructuring food environments, such as online grocery stores, has the potential to improve consumer health by encouraging healthier food choices. The aim of this study was to investigate whether repositioning foods within an experimental online grocery store can be used to nudge healthier choices. Specifically, we investigated whether repositioning product categories displayed on the website main page, and repositioning individual products within those categories, will influence selection. Adults residing in Australia (n = 175) were randomised to either intervention (high-fibre foods on top) or comparator condition (high-fibre foods on the bottom). Participants completed a shopping task using the experimental online grocery store, with a budget of up to AU$100 to for one person's weekly groceries. The results of this study show that the total fibre content per 100 kcal per cart (p < .001) and total fibre content per cart (p = .036) was higher in the intervention compared to comparator condition. Moreover, no statistical difference between conditions was found for the total number of fibre-source foods (p = .67), the total energy per cart (p = .17), and the total grocery price per cart (p = .70) indicating no evidence of implications for affordability. Approximately half of the participants (48%) reported that they would like to have the option to sort foods based on a specific nutrient criterion when shopping online. This study specifically showed that presenting higher-fibre products and product categories higher up on the online grocery store can increase the fibre content of customers' purchases. These findings have important implications for consumers, digital platform operators, researchers in health and food domains, and for policy makers.

Simple dietary substitutions can reduce carbon footprints and improve dietary quality across diverse segments of the US population

Changing what foods we eat could reduce environmental harms and improve human health, but sweeping dietary change is challenging. We used dietary intake data from a nationally representative sample of 7,753 US children and adults to identify simple, actionable dietary substitutions from higher- to lower-carbon foods (for example, substituting chicken for beef in mixed dishes such as burritos, but making no other changes to the diet). We simulated the potential impact of these substitutions on dietary carbon emissions and dietary quality. If all consumers who ate the high-carbon foods instead consumed a lower-carbon substitute, the total dietary carbon footprint in the United States would be reduced by more than 35%. Moreover, if adopted, these substitutions would improve consumers' overall dietary quality by 4-10%, with benefits projected for all age, gender, and racial and ethnic groups. These results suggest that a 'small changes' approach could be a valuable starting point for addressing diet's impact on climate and health.

Exploring the role of decision support systems in promoting healthier and more sustainable online food shopping: A card sorting study

This study aims to identify opportunities and barriers in developing and implementing Food Shopping Support Systems (FSSS) for healthier and more sustainable choices, given the growing consumer demand and persistent societal problems related to food. The study examined the social and technical value of FSSS in an early development stage through one-on-one expert interviews (n = 20) and consumer focus groups (4 groups, n = 19). Experts were employed in the fields of behavioral sciences, digital marketing, decision aids, software development, persuasive technologies, and public health and sustainability. Consumer participants were used to shopping online. Through a card sorting task followed by semi-structured interview questions, responses were elicited. Participants were presented with 17 cards in 5 rounds, each addressing a different topic related to decision support. Results show that support is perceived useful, particularly when suggestions are personalized, transparent, and justified (using labelling or informative text). Opportunities for uptake were presenting suggestions early in the shopping trip in a visible but non-disruptive manner, allowing autonomy to choose the type of guidance (e.g., show sustainable but not healthier suggestions) and to (not) provide personal data, and educating consumers. Negative attitudes were associated with support being disruptive or steering, being of low credibility, and unclarity about what is healthy or sustainable. Consumer participants expressed concerns about too generic suggestions in relation to health and lack of knowledge about labelling. They emphasized that excessive support and required effort, such as repeatedly providing data, can be burdensome. Experts also worried about limited consumer interest and not having the required data to provide support. Results from this study reveal the potential for successful digital interventions to encourage healthier and more sustainable choices and what this means for further development.

Evaluating the relative impact of multiple healthy food choice interventions on choice process variables and choices

Fiscal tools-taxes and/or subsidies-are increasingly used to address diet-related health problems. However, some studies have found that these tools are markedly more effective if attention is drawn to the tax or subsidy, suggesting that the price change alone may go unnoticed in the complex food environments that consumers face. Interventions that prompt individuals to consider health during choice show promise for promoting healthy food choices in both simple laboratory settings and complex, real-world markets. In this pre-registered study, I examine the impact of dietary fiber health prompts and/or dietary fiber subsidies on the per-serving fiber content of foods chosen, the documented set of products considered, and (self-reported) nutrition information use by participants in an online supermarket setting. Participants were randomized to one of four conditions: 1) control, 2) subsidy, 3) fiber prompt, and 4) fiber prompt + subsidy. Results show that both the prompt and prompt + subsidy conditions significantly increase fiber content of foods chosen (with the latter having a larger effect). While all three interventions influence the probability of using nutrition information during food choice and affect the set of products that respondents consider relative to the control condition, the effects were larger for the prompt and prompt + subsidy conditions. A multiple mediation analysis illustrates that both direct and indirect (through the set of products considered and the use of fiber information during choice) pathways lead to the significant overall increase in fiber content of selected foods.

Framed or Unframed? An empirical study of the impact of food brand logo frame on consumers' food preferences

Despite the widespread use of food brand logo frame in food brand logo cues, little is known about how food brand logo frame influences consumers' food preferences. Through five studies, this article explores the food brand logo frame on consumers' food preferences for different food types. For utilitarian foods, framed (vs unframed) food brand logos result in higher (lower) consumers' food preferences (Study 1), and this framing effect is driven by the psychological mechanism of food safety associations (Study 2); for hedonic foods, unframed (vs framed) food brand logos result in higher (lower) consumers' food preferences (Study 3), and this framing effect is driven by the psychological mechanism of food confinement associations (Study 4). Furthermore, this framing effect was also observed among UK consumers (Study 5). The findings contribute to the literature of brand logo and frame effect, as well as to the literature of food association, and bear important implications regarding food brand logo frame design for food marketers when developing food brand logo programs.

Testing the impact of overt and covert ordering interventions on sustainable consumption choices: A randomised controlled trial

Food products have significant impacts on the environment over their life cycle. We investigated whether displaying products in ascending order of carbon footprint in an online supermarket environment can shift consumer choices towards more sustainable options. We examined whether the effect of the ordering intervention differs when the ordering is overt (information about the ordering is explicit), compared to when it is covert (participants not told about the ordering). We conducted a three-arm parallel-group randomised trial using 1842 online participants from England, Wales, and Northern Ireland. Participants shopped for a meal, choosing one product from each of six product categories in a simulated online supermarket. Six products were listed vertically on each product-category page. Products were randomly ordered for the control arm but ordered by carbon footprint in the covert and overt ordering arms. In the overt ordering arm, a statement was displayed at the top of each product page about the ordering of products. The primary outcome was whether one of the three most sustainable products was chosen in each product category. There was no effect of the covert ordering on the probability of choosing more sustainable products compared with the control arm (OR = 0.97, 95% CI 0.88-1.07, p = 0.533). Furthermore, we did not find evidence that the effects of the covert ordering and overt ordering differed (p = 0.594). Within the control condition, products in different positions were chosen with similar frequencies, suggesting that product positioning does not have an impact on choices. This may explain why re-ordering products had no effect. In the overt condition, only 19.5% of people correctly answered that the products were ordered according to sustainability in a follow-up question, suggesting that they didn't notice the statement. Results suggest that choices for grocery products might be too ingrained to be changed by subtle rearrangements of choice architecture like the ordering interventions, and highlight the difficulty of conveying information effectively to consumers in the online grocery shopping environment.

A Systematic Review of Marketing Practices Used in Online Grocery Shopping: Implications for WIC Online Ordering

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) plans to allow participants to redeem their food package benefits online, i.e., online ordering. As grocery shopping online has become more common, companies have developed strategies to market food products to customers using online (or mobile) grocery shopping platforms. There is a significant knowledge gap in how these strategies may influence WIC participants who choose to shop for WIC foods online. This review examines the relevant literature to (1) identify food marketing strategies used in online grocery shopping platforms, (2) understand how these strategies influence consumer behavior and consumer diet, and (3) consider the implications for WIC participants. A total of 1862 references were identified from a systematic database search, of which 83 were included for full-text screening and 18 were included for data extraction and evidence synthesis. The included studies provide policymakers and other stakeholders involved in developing WIC online order processes with valuable information about the factors that shape healthy food choices in the online food retail environment. Findings indicate that some marketing interventions, such as nutrition labeling and food swaps, may encourage healthier food choices in the online environment and could potentially be tailored to reinforce WIC messaging about a healthy diet.

Perceptions of social norms around healthy and environmentally-friendly food choices: Linking the role of referent groups to behavior

Referent groups can moderate the perception of social norms and individuals’ likelihood to model these norms in food choice contexts, including vegetable intake and reduced meat consumption. The present study investigated whether having a close vs. a distant social group as the referent changed perceptions of social norms around making healthy and eco-friendly food choices. It also assessed whether these changes were associated with a difference in the health and environmental impacts of food choice in a virtual grocery shopping task. A nationally representative sample of UK adults (N = 2,488) reported their perceptions of making healthy and eco-friendly food choices being the norm among people they share meals with (close referent group) and most people in the UK (distant referent group). The former was more commonly perceived to be making both healthy (Z = −12.0, p &lt; 0.001) and eco-friendly (Z = −13.27, p &lt; 0.001) food choices than the latter. Perceptions of norms referring to the close group were significantly associated with the environmental (β = −0.90, 95% CIs: −1.49, −0.28) and health (β = −0.38 p &lt; 0.05, 95% CIs: −0.68, −0.08) impacts of participants’ food choices in a virtual shopping task. No such relationship was found for norms referring to the distant group for both environmental (β =0.43, p &gt; 0.05, 95% CIs: −1.12, 0.25) and health (β = −0.06, p &gt; 0.05, 95% CIs: −0.37, 0.25) impacts. Framing social norms around making healthy and eco-friendly food choices to refer to a close referent group may change their perceptions and ability to encourage sustainable and healthy food purchasing.

Strategies to reduce the energy content of foods pre-ordered for lunch in the workplace: a randomised controlled trial in an experimental online canteen

BACKGROUND

Prompting employees to swap their usual lunches for lower-energy alternatives may help align energy intake with public health recommendations. We tested the effect of offering lower-energy swaps with and without physical activity calorie equivalent (PACE) information on the energy of lunches pre-ordered in an online hypothetical workplace canteen.

METHODS

UK employed adults (n = 2,150) were invited to hypothetically pre-order their lunch from the canteen through a custom-made online platform. They were randomised 1:1:1 to: (i) control: no swaps offered; (ii) lower-energy swaps offered; or (iii) lower-energy swaps offered with PACE information. The primary outcome was the total energy ordered using analysis of covariance and controlling for the energy content of the initial items ordered. Secondary outcomes were swap acceptance rate and intervention acceptability.

RESULTS

Participants were 54% female, had a mean age of 36.8 (SD = 11.6) and a BMI of 26.3 (SD = 5.6). Compared with an average 819 kcal energy ordered in the control, both the swaps and swaps + PACE interventions significantly reduced average energy ordered by 47 kcal (95% CI: -82 to -13, p = 0.003) and 66 kcal (95% CI: -100 to -31, p < 0.001), respectively. Compared with offering swaps only, the swaps + PACE intervention led to significantly higher swap acceptance (OR: 1.63, 95% CI: 1.27 to 2.09, p < 0.001) but did not significantly reduce energy ordered (-19 kcal, 95% CI: -53 to 16, p = 0.591). About 65% and 16% of intervention participants found the swap interventions acceptable and unacceptable, respectively, with the swaps + PACE intervention being considered more acceptable than swaps only (OR: 1.32, 95%CI: 1.09 to 1.60, p < 0.004).

CONCLUSION

Offering lower-energy swaps with or without PACE information reduced the energy of pre-ordered lunches experimentally. Both interventions hold promise for reducing the energy of purchased foods and drinks. Trial Registration As Predicted reference number: 56358, 22/01/21, https://aspredicted.org/pw2qr.pdf.

Content Analysis of Online Grocery Retail Policies and Practices Affecting Healthy Food Access

OBJECTIVE

To describe policies and practices of online grocery retailers that may affect healthy food access, including retailers participating in the US Department of Agriculture's Supplemental Nutrition Assistance Program Online Purchasing Pilot.

DESIGN

Cross-sectional, quantitative content analysis of 21 online grocery retail websites from November 2019 to January 2020.

MAIN OUTCOME MEASURES

Data collected using a coding instrument capturing the presence of policies and practices related to (1) online purchasing and delivery access; (2) availability of features that allow price comparisons and provide nutrition information; and (3) data privacy.

ANALYSIS

Descriptive statistics for features, practices, and policies across online grocery retail websites.

RESULTS

Most retailers (95%) added fees to online orders. Among pilot retailers, 38% added ≥ 3 fees, and 50% required a minimum order > $15. Few retailers (29%) displayed Nutrition Facts Labels on all products, including 50% of pilot retailers. All retailers collected personal information from shoppers and automatically shared data with affiliated companies.

CONCLUSIONS AND IMPLICATIONS

High fees, limited access to nutrition information on retailer sites, and lack of data privacy are prevalent in online grocery retail settings, including among Online Purchasing Pilot retailers. Online retail practices may perpetuate disparities in healthy food access by discouraging use through fees and making nutritious food choices difficult.

Evaluation of Combinations of Nudging, Pricing, and Labeling Strategies to Improve Diet Quality: A Virtual Grocery Store Experiment Employing a Multiphase Optimization Strategy

BACKGROUND

Several intervention strategies have been shown to improve diet quality. However, there is limited evidence on the increase in effectiveness that may be achieved through select combinations of these strategies.

PURPOSE

This study aimed to identify an effective multicomponent intervention to improve diet quality of a grocery basket by applying a Multiphase Optimization Strategy framework and testing various combinations of four promising strategies using a fully functional web-based grocery store: (i) front-of-pack food labels and real-time feedback of the healthiness of the shoppers' grocery basket, (ii) a tax, (iii) ordering products by a nutritional quality score, and (iv) healthier substitute offers.

METHODS

We conducted a hypothetical shopping study (N = 756) with a randomized full factorial design (16 conditions) to estimate main and interaction effects of the four interventions.

RESULTS

The "food labels & real-time feedback" and "ordering" strategies had significantly positive main effects on overall diet quality of the shopping basket (both at p < .001). We found no effects on diet quality for the "tax" and "healthier substitute offers." None of the two-way interaction effects for different strategies on overall diet quality and nutrients were significant.

CONCLUSIONS

Having "food labels & real-time feedback" and "ordering" simultaneously seemed to be more effective at improving diet quality, compared to having only one of these interventions. These results suggest that a combination of food labels with real-time feedback and ordering interventions can be part of a promising multicomponent strategy to improve diet quality in online shopping platforms.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04632212.

Nudging customers towards healthier food and beverage purchases in a real-life online supermarket: a multi-arm randomized controlled trial

BACKGROUND

Nudging is increasingly used to promote healthy food choices in supermarkets. Ordering groceries online is gaining in popularity and nudging seems efficacious there as well, but is never comprehensively tested in real-life. We evaluated the real-life effectiveness of nudging in an online supermarket on healthy food purchases.

METHODS

We conducted a multi-arm, parallel-group, individually randomized controlled trial in an online supermarket. During 1 month, all customers were randomized to (1) control condition, (2) information nudges, (3) position nudges, and (4) information and position nudges combined. Allocation was concealed and customers were not blinded, but unaware of the intervention. Mean differences between the control condition and the intervention arms in the total percentage of healthy purchases were assessed with a linear mixed model. We tested for effect modification by area-level deprivation.

RESULTS

Based on sales data from 11,775 shoppers, no overall significant effects were detected. Yet, effects were modified by area-level deprivation (pArm 2 < 0.001). Among shoppers from deprived areas, those allocated to information nudges purchased a 2.4% (95%CI 0.8, 4.0) higher percentage of healthy products compared to controls. No significant differences were observed for position (- 1.3%; 95%CI - 2.8, 0.3) and combined nudges (- 0.1%; 95%CI - 1.7, 1.5). Shoppers from non-deprived areas exposed to information nudges (- 1.6%; 95%CI - 3.2, - 0.1) and the combined nudges (- 2.1%; 95%CI - 3.6, - 0.6), but not position nudges (- 0.9%; 95%CI - 2.4, 0.7), purchased a lower percentage of healthy products.

CONCLUSION

Information nudges in an online supermarket can increase healthy product purchases, but only for those living in deprived areas. The adverse effects found on purchasing behaviors for those from non-deprived areas call for further research. Further research should also focus on real-life effects of online healthy food nudging as part of a broader nutrition intervention strategy, and on the equitability of the online nudging intervention within populations.

TRIAL REGISTRATION

Retrospectively registered in the ISRCTN registry at May 21, 2021 ( ISRCTN10491616 ).

Digital Nudging for Online Food Choices

When people search for what to cook for the day, they increasingly use online recipe sites to find inspiration. Such recipe sites often show popular recipes to make it easier to find a suitable choice. However, these popular recipes are not always the healthiest options and can promote an unhealthy lifestyle. Our goal is to understand to what extent it is possible to steer the food selection of people through digital nudging. While nudges have been shown to affect humans' behavior regarding food choices in the physical world, there is little research on the impact of nudges on online food choices. Specifically, it is unclear how different nudges impact (i) the behavior of people, (ii) the time they need to make a decision, and (iii) their satisfaction and confidence with their selection. We investigate the effects of highlighting, defaults, social information, and warnings on the decision-making of online users through two consecutive user studies. Our results show that a hybrid nudge, which both involves setting a default and adding social information, significantly increases the likelihood that a nudged item is selected. Moreover, it may help decreasing the required decision time for participants while having no negative effects on the participant's satisfaction and confidence. Overall, our work provides evidence that nudges can be effective in this domain, but also that the type of a digital nudge matters. Therefore, different nudges should be evaluated in practical applications.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

Sugar-sweetened beverage consumption among adults in rural Appalachia

Sugar-sweetened beverage (SSB) consumption is decreasing nationally, yet intakes remain high in certain sub-populations as new varieties of SSBs are introduced. This study aims to expand on SSB intake patterns among adults living in Appalachia to develop policy, systems, and environmental (PSE) interventions to reduce consumption. Baseline cohort surveys were conducted to examine beverage consumption patterns of adults in one rural Appalachian county in Kentucky using a validated BEVQ-15 instrument. Ages were collapsed into three generational groups - Millennials (22-38 years), Generation X (39-54 years), and Boomers/Silents (≥55 years). Over half (n = 81; 54%) of the sample (n = 150) were Boomers/Silents. Age was a significant predictor of SSB consumption, with Millennials drinking more daily calories of SSB compared to older adults (329.2 kcal v 157.0 kcal v 134.6 kcal, p = 0.05); a significant amount of those calories coming from non-soda SSBs. Millennials were twice as likely to drink sweetened fruit juice drinks (p = 0.0002) and energy drinks (p = 0.01) daily and consumed six times more daily calories from sweetened fruit juice drinks than the other groups (73.5 kcal v 11.1 kcal v 8.0 kcal, p < 0.01). To our knowledge, this is the first study to show beverage choices and consumption patterns in Appalachian adults vary by age and non-soda SSBs are significant sources of added sugar. These findings inform PSE interventions for reducing SSB consumption, such as tailored marketing approaches and technology-based strategies, within a unique setting, and offer insight for nutrition educators and public health professionals working within rural, remote communities.

Digital Food Retail: Public Health Opportunities

For over two decades, digital food retail services have been emerging alongside advances in mobile technology and improved access to wi-fi. Digitalization has driven changes within the food environment, complicating an already complex system that influences food-related behaviors and eating practices. Digital food retail services support an infrastructure that enhances commercial food systems by extending access to and availability of highly processed foods, further escalating poor dietary intakes. However, digital food retail services are heterogeneous–food delivery apps, online groceries, and meal kits–and can be feasibly adapted to nutrition interventions and personalized to individual needs. Although sparse, new evidence indicates great potential for digital food retail services to address food insecurity in urban areas and to support healthy eating by making it easier to select, plan, and prepare meals. Digital food retail services are a product of the digital transformation that reflect consumers’ constant need for convenience, which must be addressed in future research and interventions. This paper will discuss public health opportunities that are emerging from the global uptake of digital food retail services, with a focus on online groceries, food delivery apps, and meal kits.

A Standardized Guide to Developing an Online Grocery Store for Testing Nutrition-Related Policies and Interventions in an Online Setting

Simulated online grocery store platforms are innovative tools for studying nutrition-related policies and point-of-selection/point-of-purchase interventions in online retail settings, yet there is no clear guidance on how to develop these platforms for experimental research. Thus, we created a standardized guide for the development of an online grocery store, including a detailed description of (1) methods for acquiring and cleaning online grocery store data, and (2) how to design a two-dimensional online grocery store experimental platform. We provide guidance on how to address product categorization, product order/sorting and product details, including how to identify outliers and conflicting nutritional information and methods for standardizing prices. We also provide details regarding our process of “tagging” food items that can be leveraged by future studies examining policies and point-of-selection/point-of-purchase interventions targeting red and processed meat and fruits and vegetables. We experienced several challenges, including obtaining accurate and up-to-date product information and images, and accounting for the presence of store-brand products. Regardless, the methodology described herein will enable researchers to examine the effects of a wide array of nutrition-related policies and interventions on food purchasing behaviors in online retail settings, and can be used as a template for reporting procedures in future research.

Designing online grocery stores to support healthy eating for weight loss

OBJECTIVES

The current study aimed to identify features to include in online grocery stores to support healthful food purchasing by those striving to lose weight.

DESIGN

A Value Proposition Design approach was used to gain shopper insights, devise potential online grocery store features and obtain feedback on these features.

SETTING

Telephone interviews were conducted to gain insight into shoppers' needs and perceptions. Results were used by the research team to identify potential online grocery shopping features that may support healthful purchase decisions, and interviews were conducted with a different sample of shoppers to gather feedback on features.

PARTICIPANTS

Insight (n 25) and feedback (n 25) interviews were conducted with convenience samples of adults trying to lose weight.

RESULTS

Participants were primarily female, white, college educated and with obesity or overweight. Online grocery features devised by the research team based on findings from the insight interviews included (1) shopping cart nutrition rating tool; (2) healthy meal planning tool; (3) interactive healthy eating inspiration aisle and (4) healthy shopping preference settings option. Findings from the feedback interviews indicated that the healthy meal planning tool, healthy shopping preference settings option and shopping cart nutrition rating tool features were positively rated by most participants.

CONCLUSIONS

There are multiple features grocers should consider including in their online stores to attract and support customers striving to eat healthy for weight loss.

The effect of messaging on the acceptance of swaps to reduce the energy content of snacks and non-alcoholic drinks ordered in an experimental online workplace canteen: A randomised controlled trial

Finding effective ways to increase acceptance of lower-energy swaps offered for snacks and non-alcoholic drinks may reduce population energy intake. We examined whether incrementally increasing the tangibility of information accompanying swaps offered increased their acceptance. UK adults (n = 3481) selected a sweet snack, a savoury snack, and a drink in an experimental online canteen after being equally randomised to receive one of four messages when swaps were offered; a control message providing no specific information, a vague calorie message, an exact numeric-calories message or, a physical activity calorie equivalent (PACE). Primary outcomes were the between-group differences in (i) the odds that a sweet, savoury, or drink swap would be accepted and (ii) the energy content for each type of item ordered. Compared with control, the numeric-calories and PACE messages significantly increased the odds of accepting a sweet snack swap. All interventions significantly increased the odds of accepting savoury swaps compared with control. Only the PACE message significantly increased the odds of drink swap acceptance. The numeric-calories and PACE messages significantly reduced the energy content of sweet snacks. All interventions significantly reduced the energy content of savoury snacks. None of the intervention messages significantly reduced the energy content of drinks compared with control. Increasing the tangibility of information provided when offering swaps increased swap acceptance. PACE messaging was the most promising.

A randomised experiment of health, cost and social norm message frames to encourage acceptance of swaps in a simulation online supermarket

Offering lower-energy food swaps to customers of online supermarkets could help to decrease energy (kcal) purchased and consumed. However, acceptance rates of such food swaps tend to be low. This study aimed to see whether framing lower-energy food swaps in terms of cost savings or social norms could improve likelihood of acceptance relative to framing swaps in terms of health benefits. Participants (n = 900) were asked to shop from a 12-item shopping list in a simulation online supermarket. When a target high-energy food was identified in the shopping basket at check-out, one or two lower-energy foods would be suggested as an alternative (a “swap”). Participants were randomised to only see messages emphasising health benefits (fewer calories), cost benefits (lower price) or social norms (others preferred this product). Data were analysed for 713 participants after exclusions. Participants were offered a mean of 3.17 swaps (SD = 1.50), and 12.91% of swaps were accepted (health = 14.31%, cost = 11.49%, social norms = 13.18%). Swap acceptance was not influenced by the specific swap frame used (all p > .170). Age was significantly and positively associated with swap acceptance (b = 0.02, SE = 0.00, p < .001), but was also associated with smaller decreases in energy change (b = 0.46, SE = .19, p = .014). Overall, offering swaps reduced both energy (kcal) per product (b = -9.69, SE = 4.07, p = .017) and energy (kcal) per shopping basket (t₇₁₂ = 11.09, p < .001) from pre- to post-intervention. Offering lower-energy food swaps could be a successful strategy for reducing energy purchased by customers of online supermarkets. Future research should explore alternative solutions for increasing acceptance rates of such swaps.

Experience of Using an Online Pre-Ordering System for A Workplace Canteen That Offers Lower-Energy Swaps: A Think-Aloud Study

Online systems that allow employees to pre-order their lunch may help reduce energy intake. We investigated the acceptability of a pre-ordering website for a workplace canteen that prompts customers to swap to lower-energy swaps and the factors influencing swap acceptance. Employees (n = 30) placed a hypothetical lunch order through a pre-ordering website designed for their canteen while thinking aloud. Semi-structured interview questions supported data collection. Data were analysed using thematic analysis. Acceptability was generally high, but potentially context dependent. Practical considerations, such as reminders to pre-order, user-friendliness, provision of images of menu items and energy information while browsing, an ability to reserve pre-ordered meals, and a swift collection service facilitated acceptability. The restrictive timeframe within which orders could be placed, a lack of opportunity to see foods before ordering, and prompts to swap being perceived as threatening autonomy were barriers to acceptability. Swap acceptance was facilitated by the provision of physical activity calorie equivalents (PACE) information, and swap similarity in terms of taste, texture, and expected satiety as well as the perception that alternatives provided meaningful energy savings. Online canteen pre-ordering systems that prompt lower-energy swaps may be an acceptable approach to help reduce energy intake in the workplace.

Effects of Labelling and Increasing the Proportion of Lower-Energy Density Products on Online Food Shopping: A Randomised Control Trial in High- and Low-Socioeconomic Position Participants

Reducing the energy density (ED) of product selections made during online supermarket food shopping has potential to decrease energy intake. Yet it is unclear which types of intervention are likely to be most effective and equitable. We recruited 899 UK adults of lower and higher socioeconomic position (SEP) who completed a shopping task in an online experimental supermarket. Participants were randomised in a 2 × 2 between-subjects design to test the effects of two interventions on the ED of shopping basket selections: labelling lower-ED products as healthier choices and increasing the relative availability of lower-ED products within a range (referred to as proportion). Labelling of lower-ED products resulted in a small but significant decrease (−4.2 kcal/100 g, 95% CIs −7.8 to −0.6) in the ED of the shopping basket. Increasing the proportion of lower-ED products significantly decreased the ED of the shopping basket (−17 kcal/100 g, 95% CIs −21 to −14). There was no evidence that the effect of either intervention was moderated by SEP. Thus, both types of intervention decreased the ED of foods selected in an online experimental supermarket. There was no evidence that the effectiveness of either intervention differed in people of lower vs. higher SEP.

Prominent positioning and food swaps are effective interventions to reduce the saturated fat content of the shopping basket in an experimental online supermarket: a randomized controlled trial

BACKGROUND

Interventions to reduce the saturated fat (SFA) content of food purchases may help reduce SFA consumption and lower cardiovascular risk. This factorial RCT aimed to examine the effect of altering the default order of foods and being offered a swap on the SFA content of food selected during an online shopping experiment.

METHODS

UK adults who were the primary grocery shoppers for their household were recruited online and invited to select items in a custom-made experimental online supermarket using a 10-item shopping list. Participants were randomly allocated to one of four groups (i) to see products within a category ranked in ascending order of SFA content, (ii) receive an offer to swap to a product with less SFA, (iii) a combination of both interventions, or (iv) no intervention. The primary outcome was the difference in percentage energy from SFA in the shopping basket between any of the four groups. The outcome assessors and statistician were blinded to intervention allocation.

RESULTS

Between March and July 2018, 1240 participants were evenly randomised and 1088 who completed the task were analysed (88%). Participants were 65% female and aged 38y (SD 12). Compared with no intervention (n = 275) where the percentage energy from SFA was 25.7% (SD 5.6%), altering the order of foods (n = 261) reduced SFA by [mean difference (95%CI)] -5.0% (- 6.3 to - 3.6) and offering swaps (n = 279) by - 2.0% (- 3.3 to - 0.6). The combined intervention (n = 273) was significantly more effective than swaps alone (- 3.4% (- 4.7 to - 2.1)) but not different than altering the order alone (- 0.4% (- 1.8 to 0.9)), p = 0.04 for interaction.

CONCLUSIONS

Altering the default order to show foods in ascending order of SFA and offering a swap with lower SFA reduced percentage energy from SFA in an experimental online supermarket. Environmental-level interventions, such as altering the default order, may be a more promising way to improve food purchasing than individual-level ones, such as offering swaps.

TRIAL REGISTRATION

ISRCTN13729526 https://doi.org/10.1186/ISRCTN13729526 26th February 2018.

Optimising swaps to reduce the salt content of food purchases in a virtual online supermarket: A randomised controlled trial

Background

Offering consumers the opportunity to swap to lower-salt foods while shopping has potential to reduce salt intake. Offering a wider range of alternatives which are much lower in salt could increase the magnitude of salt reduction gained but may interfere with consumers’ engagement and willingness to accept swaps.

Objectives

To compare the salt reduction from offering swaps to a similar product but with minimally less salt to offering swaps with a substantial salt reduction including a range of alternative foods.

Methods

In an experimental, randomised trial conducted in a virtual online supermarket, participants with high blood pressure were asked to buy 12 items of food. One group was offered similar alternatives with 5–20% less salt (LS swaps); and the other group was offered these LS swaps and alternatives with >20% less salt (MLS swaps). The primary outcome was the change in salt density of the shopping basket (g/100g) from initially selected items, to the final items chosen.

Results

947 participants completed the task and were included in the analysis. There was a significant reduction in salt content of the final selected shopping basket in both groups; with a significantly greater reduction in the group offered LS + MLS swaps (−0.09g/100g, 95% C.I. −0.10, −0.07; p < 0.001). The proportion of swaps accepted was the same in both groups and the mean salt reduction per swap accepted in the group offered LS + MLS swaps was more than double that of the group offered LS swaps alone. 30% of MLS swaps accepted were from a different food subcategory.

Conclusions

Offering alternative products with a large reduction in salt, including potentially dissimilar products, does not decrease acceptability and leads to significantly greater reductions in the salt content of the shopping basket.

Trial registration

ISRCTN, ISRCTN91306993. Registered 5th February 2018 – retrospectively registered. https://www.isrctn.com/ISRCTN91306993.

Online grocery shopping: promise and pitfalls for healthier food and beverage purchases

Objectives

(i) To determine the current state of online grocery shopping, including individuals’ motivations for shopping for groceries online and types of foods purchased; and (ii) to identify the potential promise and pitfalls that online grocery shopping may offer in relation to food and beverage purchases.

Design

PubMed, ABI/INFORM and Google Scholar were searched to identify published research.

Setting

To be included, studies must have been published between 2007 and 2017 in English, based in the USA or Europe (including the UK), and focused on: (i) motivations for online grocery shopping; (ii) the cognitive/psychosocial domain; and (iii) the community or neighbourhood food environment domain.

Subjects

Our search yielded twenty-four relevant papers.

Results

Findings indicate that online grocery shopping can be a double-edged sword. While it has the potential to increase healthy choices via reduced unhealthy impulse purchases, nutrition labelling strategies, and as a method to overcome food access limitations among individuals with limited access to a brick-and-mortar store, it also has the potential to increase unhealthy choices due to reasons such as consumers’ hesitance to purchase fresh produce online.

Conclusions

Additional research is needed to determine the most effective ways to positively engage customers to use online grocery shopping to make healthier choices.

Interventions targeting conscious determinants of human behaviour to reduce the demand for meat: a systematic review with qualitative comparative analysis

BACKGROUND

Reducing meat consumption can help prevent non-communicable diseases and protect the environment. Interventions targeting conscious determinants of human behaviour are generally acceptable approaches to promote dietary change, but little is known about their effectiveness to reduce the demand for meat.

OBJECTIVE

To evaluate the effectiveness of interventions targeting conscious determinants of human behaviour to reduce the demand for meat.

METHODS

We searched six electronic databases on the 31st of August 2017 with a predefined algorithm, screened publicly accessible resources, contacted authors, and conducted forward and backward reference searches. Eligible studies employed experimental designs to evaluate interventions targeting conscious determinants of human behaviour to reduce the consumption, purchase, or selection of meat in comparison to a control condition, a baseline period, or relative to other eligible interventions. We synthesised results narratively and conducted an exploratory crisp-set Qualitative Comparative Analysis to identify combinations of intervention characteristics associated with significant reductions in the demand for meat.

RESULTS

We included 24 papers reporting on 59 interventions and 25,477 observations. Self-monitoring interventions and individual lifestyle counselling led to, or were associated with reduced meat consumption. Providing information about the health or environmental consequences of eating meat was associated with reduced intentions to consume and select meat in virtual environments, but there was no evidence to suggest this approach influenced actual behaviour. Education about the animal welfare consequences of eating meat was associated with reduced intentions to consume meat, while interventions implicitly highlighting animal suffering were not. Education on multiple consequences of eating meat led to mixed results. Tailored education was not found to reduce actual or intended meat consumption, though few studies assessed this approach.

CONCLUSION

Some interventions targeting conscious determinants of human behaviour have the potential to reduce the demand for meat. In particular, self-monitoring interventions and individual lifestyle counselling can help to reduce meat consumption. There was evidence of effectiveness of some educational messages in reducing intended consumption and selection of meat in virtual environments.

PROTOCOL REGISTRATION

CRD42017076720 .

Restructuring physical micro-environments to reduce the demand for meat: a systematic review and qualitative comparative analysis

BACKGROUND

Reducing meat consumption could help to protect the natural environment and promote population health. Interventions restructuring physical micro-environments might help to change habitual behaviour. We synthesised the scientific evidence pertaining to whether, and which, interventions restructuring physical micro-environments effectively reduce the demand for meat.

METHODS

We did a systematic review of quantitative studies evaluating the effectiveness of interventions restructuring physical micro-environments to reduce the demand for meat. We identified relevant records by searching six electronic databases (CAB Abstracts, Embase, PsycINFO, Science Citation Index, MEDLINE, and Dissertations & Theses) on Aug 31, 2017, contacting experts, screening publicly accessible online resources, and searching references. We included studies that evaluated the effectiveness of interventions restructuring physical micro-environments to reduce the demand for meat, defined as the actual or intended consumption, purchase, or selection of meat in real or virtual environments. We extracted data pertaining to the study samples, the interventions, and meat demand at the follow-up closest to intervention completion and at the longest follow-up, with the former representing our primary outcome. We synthesised data narratively and did a qualitative comparative analysis to identify configurations of intervention characteristics associated with, and those not found to be associated with, significant reductions in meat demand. Our Systematic Review is registered with PROSPERO, number CRD42017081532.

RESULTS

Of 10 733 titles and abstracts screened for eligibility, we assessed 60 full papers and included 14 papers reporting on 18 studies with 22 intervention conditions. Three interventions reducing the portion size of meat servings reduced meat consumption in randomised trials. Three interventions providing meat alternatives with supporting educational material were associated with reduced meat demand in pre-post design studies. Three of four interventions altering the sensory properties (eg, visual presentation) of meat or meat alternatives at point of purchase reduced meat demand in randomised trials. Four interventions repositioning meat products to be less prominent at point of purchase were associated with lower meat demand, but only two such interventions reached statistical significance in a randomised trial and a multiple treatment reversal design. Only one of five interventions manipulating the description of meat or meat alternatives at point of purchase was associated with lower meat demand in a multiple treatment reversal design. Evidence from randomised trials evaluating a pricing intervention or interventions restructuring several aspects of micro-environments was too scarce or inconsistent to be conclusive. The results from our qualitative comparative analysis supported the findings of this narrative synthesis.

INTERPRETATION

Some interventions restructuring physical micro-environments could help to promote lower demand for meat. Interventions reducing portion sizes of meat servings, providing meat alternatives, or changing the sensory properties of meat and meat alternatives at point of purchase offered the most promise in the context of experimental studies.

FUNDING

None.

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

Background

Diet is an important determinant of health, and food purchasing is a key antecedent to consumption.

Objective

We set out to evaluate the effectiveness of grocery store interventions to change food purchasing, and to examine whether effectiveness varied based on intervention components, setting, or socioeconomic status.

Design

We conducted a systematic review of randomized controlled trials (search performed June 2017). Studies must have: aimed to change food purchasing; been implemented in grocery stores (real or simulated); reported purchasing; and had a minimal control or compared interventions fulfilling our criteria. Searching, screening, bias assessment, and data extraction followed Cochrane methods. We grouped studies by intervention type (economic, environmental, swaps, and/or education), synthesized results narratively, and conducted an exploratory qualitative comparative analysis.

Results

We included 35 studies representing 89 interventions, >20,000 participants, and >800 stores. Risk of bias was mixed. Economic interventions showed the most promise, with 8 of the 9 studies in real stores and all 6 in simulated environments detecting an effect on purchasing. Swap interventions appeared promising in the 2 studies based in real stores. Store environment interventions showed mixed effects. Education-only interventions appeared effective in simulated environments but not in real stores. Available data suggested that effects of economic interventions did not differ by socioeconomic status, whereas for other interventions impact was variable. In our qualitative comparative analysis, economic interventions (regardless of setting) and environmental and swap interventions in real stores were associated with statistically significant changes in purchasing in the desired direction for ≥1 of the foods targeted by the intervention, whereas education-only interventions in real stores were not.

Conclusions

Findings suggest that interventions implemented in grocery stores-particularly ones that manipulate price, suggest swaps, and perhaps manipulate item availability-have an impact on purchasing and could play a role in public health strategies to improve health. Review protocol registered at https://www.crd.york.ac.uk/PROSPERO/ as CRD42017068809.

Priming healthy eating. You can't prime all the people all of the time

OBJECTIVE

In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population.

METHODS

In two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height.

RESULTS

In Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26-0.56), p <0.0001), an effect countered by the prime (OR (95% CI) = 2.29 (1.33-3.96), p = 0.003). In Study 2, the effect of the prime did not generalize to a representative population. More educated participants, as used in Study 1, chose more fruit when hungry and primed (OR (95% CI) = 1.42 (1.13-1.79), p = 0.003), while less educated participants' fruit choice was unaffected by hunger or the prime.

CONCLUSION

This study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice.