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

Changing the availability and positioning of more vs. less environmentally sustainable products: A randomised controlled trial in an online experimental supermarket

Food purchasing behaviours are shaped by the choices available to shoppers and the way they are offered for sale. This study tested whether prominent positioning of more sustainable food items online and increasing their relative availability might reduce the environmental impact of foods selected in a 2x2 (availability x position) factorial randomised controlled trial. Participants (n = 1179) selected items in a shopping task in an experimental online supermarket. The availability intervention added lower-impact products to the regular range. The positioning intervention biased product order to give prominence to lower-impact products. The primary outcome was the environmental impact score (ranging from 1 "least impact" to 5 "most impact", of each item in shopping baskets) analysed using Welch's ANOVA. Secondary outcomes included interactions (analysed via linear regression) by gender, age group, education, income and meat consumption and we assessed intervention acceptability (using different frames) in a post-experiment questionnaire. Compared to control (mean = 21.6), mean eco quintile score was significantly reduced when availability & order was altered (-2.30; 95%CI: 3.04; -1.56) and when order only was changed (-1.67; 95%CI: 2.42; -0.92). No significant difference between availability only (-0.02; 95%CI: 0.73; 0.69) and control was found. There were no significant interactions between interventions or by demographic characteristics. Both interventions were acceptable under certain frames (positioning emphasising lower-impact products: 70.3% support; increasing lower-impact items: 74.3% support). Prominent positioning of more sustainable products may be an effective strategy to encourage more sustainable food purchasing. Increasing availability of more sustainable products alone did not significantly alter the environment impact of products selected.

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.

Impact of front-of-pack nutrition labelling in consumer understanding and use across socio-economic status: A systematic review

An unhealthy diet is a leading contributor to the increasing burden of overweight and obesity. Front-of-pack labelling (FOPL) is being recognized as a policy strategy to promote healthier choices yet there is limited evaluation of FOPL to suggest if it is effective for all population subgroups. This systematic review aimed to assess the impact of FOPL on consumer understanding and usage across socio-economic gradients. Six electronic databases were searched through a systematic search process using key terms for FOPL and socioeconomic status (SES) from 2011 to March 2022 to include studies evaluating the effectiveness of FOPL. A narrative synthesis was conducted and the results were assessed according to the effects of FOPL on consumer awareness, understanding, and usage across SES. The review included 36 articles. In general, people of all SES groups were aware of and more likely to pay attention towards FOPL than the nutrition information panel provided on the back of the package. However, the understanding and usage were relatively poor, particularly in low SES groups. While studies conducted in low SES populations suggest FOPL increased the purchase intention of healthy products, the stratified analysis across SES showed less beneficial effects in low SES individuals. The findings highlight simplified and easy-to-understand FOPLs such as Nutri-score and traffic light labelling are likely to be effective for all populations including low SES groups. Overall, the review suggests FOPLs are more visible than the nutrition information panel and may guide healthier food choices for people of all SES backgrounds. It is unclear whether FOPL influences actual purchasing and food intake as there are insufficient studies comparing the effects among higher and lower SES populations.

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 < 0.001) and eco-friendly (Z = -13.27, p < 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 < 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 > 0.05, 95% CIs: -1.12, 0.25) and health (β = -0.06, p > 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.

The impact of increasing the availability of lower energy foods for home delivery and socio-economic position: a randomised control trial examining effects on meal energy intake and later energy intake

Increasing the availability of lower energy food options is a promising public health approach. However, it is unclear the extent to which availability interventions may result in consumers later 'compensating' for reductions in energy intake caused by selecting lower energy food options and to what extent these effects may differ based on socio-economic position (SEP). Our objective was to examine the impact of increasing availability of lower energy meal options on immediate meal energy intake and subsequent energy intake in participants of higher v. lower SEP. In a within-subjects design, seventy-seven UK adults ordered meals from a supermarket ready meal menu with standard (30 %) and increased (70 %) availability of lower energy options. The meals were delivered to be consumed at home, with meal intake measured using the Digital Photography of Foods Method. Post-meal compensation was measured using food diaries to determine self-reported energy intake after the meal and the next day. Participants consumed significantly less energy (196 kcal (820 kJ), 95 % CI 138, 252) from the menu with increased availability of lower energy options v. the standard availability menu (P < 0·001). There was no statistically significant evidence that this reduction in energy intake was substantially compensated for (33 % compensated, P = 0·57). The effects of increasing availability of lower energy food items were similar in participants from lower and higher SEP. Increasing the availability of lower energy food options is likely to be an effective and equitable approach to reducing energy intake which may contribute to improving diet and population health.

The role of health-based food choice motives in explaining the relationship between lower socioeconomic position and higher BMI in UK and US adults

Background/Objectives

Lower socioeconomic position (SEP) is associated with increased risk of higher BMI and developing obesity. No research to date has directly examined whether SEP differences in health-based food choice motives or executive function explain why lower SEP is associated with higher BMI.

Subjects/Methods

We analysed observational data from large samples of UK (N = 4130) and US (N = 1898) adults which included measures of SEP (education level, household income and subjective social status) and self-reported BMI. Participants also completed validated self-report measures on the extent to which their day-to-day food choices were motivated by health and weight control, as well as completing computerized tasks measuring inhibitory control (Stroop task) and working memory (Digit span task).

Results

Across both UK and US adults, the relationship between indicators of lower SEP and higher BMI were consistently explained by participants from lower SEP backgrounds reporting being less motivated by health when making food choices, which accounted for 18–28% of the association between lower SEP and higher BMI. There was no evidence that measures of executive function explained associations between SEP and BMI or moderated relations between food choice motives and higher BMI.

Conclusions

SEP differences in health-based food choice motives may play an important role in explaining why lower SEP is associated with an increased risk of higher BMI.

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 ).

Socioeconomic position, energy labelling and portion size selection: An online study comparing calorie and physical activity calorie equivalent (PACE) labelling in UK adults

Limited research has examined the impact of energy labelling on portion size selection. It is also unclear whether physical activity calorie equivalent (PACE) is more effective than standard kilocalorie (kcal) energy labelling in promoting healthier dietary behaviour and whether effectiveness varies based on socioeconomic position (SEP). In the present online study, 1667 UK adults of lower and higher SEP made virtual portion size selections for 18 common main meal foods under one of four conditions: kcal labelling only, PACE labelling only, kcal and PACE labelling, no labelling. Contrary to predictions, participants in the kcal labelling condition (+55 kcal, p < 0.001) chose larger portion sizes compared to the no labelling condition, whereas the PACE labelling (−17 kcal, p = 0.065) and no labelling condition did not significantly differ. The presence of PACE information on labels was associated with selection of significantly smaller portions when compared to labels that only included kcal information. Effects of labels on portion size selection were not moderated by participant SEP in primary analyses. The present study of virtual portion size selections suggests that kcal labelling resulted in larger portion size selections than no labelling, but this counter-intuitive effect was attenuated when kcal and PACE labelling were combined. Further research examining the impact of PACE labelling on real-world food selection in participants of lower and higher SEP is now warranted.

Factors associated with ordering food via online meal ordering services

OBJECTIVE

Online meal ordering services are increasing in popularity in Australia and globally. Meals ordered online for home delivery are typically less healthy than home-made meals, potentially contributing to weight gain. The aim of the present study was to identify the types of consumers who are most likely to engage in online meal ordering.

DESIGN

A cross-sectional survey including items relating to demographic and lifestyle factors was disseminated via a web panel provider.

SETTING

Australia.

PARTICIPANTS

A total of 2010 Australian adults aged 18+ years.

RESULTS

More than a quarter of respondents (28 %) engaged in online meal ordering at least once in the previous month. Younger respondents, those with a higher BMI, and those with higher education and income levels were more likely to have done so. Consuming higher levels of sugary drinks and fast-food restaurant patronage were significantly associated with ordering meals online for home delivery.

CONCLUSIONS

The outcomes of this study suggest that the use of online meal ordering services is becoming a common practice in Australia, and it is therefore important to implement evidence-based strategies and policies to encourage individuals to make healthy food choices when using these services.

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.