Socioeconomic position and the impact of increasing availability of lower energy meals vs. menu energy labelling on food choice: two randomized controlled trials in a virtual fast-food restaurant

Two online randomised controlled trials examining effects of alcohol calorie labelling on hypothetical ordering of calories from alcohol and food

BACKGROUND

Providing calorie information for alcoholic beverages is a potential public-health intervention which may serve to reduce alcohol use but also prevalence of overweight/obesity. Equivocal evidence has been found for the effectiveness of alcohol calorie information at reducing drinking intentions as well as purchasing and consumption. However, the extent at which calorie information 'on-trade' will impact consumer behaviour for both alcohol and food consumption has not been investigated.

AIMS

(1) To examine the presence of alcohol calorie labelling for hypothetical purchasing of alcohol and food in typical UK restaurant scenarios. (2) To determine the characteristics of individuals who will be likely to choose to view alcohol calorie labels.

METHODS

Two online randomised control trials using a hypothetical menu selection. In experiment one (N = 325) participants were randomised to the presence or absence of alcohol calorie labels. In experiment two (N = 1081) individuals were randomised to alcohol calorie labels absent or the choice to view alcohol calorie labels. The primary outcome for each study was calories ordered from alcoholic beverages.

RESULTS

There was no evidence that the presence of alcohol calorie information on restaurant menus impacted the number of calories ordered from alcoholic beverages or from food and soft drinks. Younger individuals and individuals who exhibit greater motives for good health were more likely to choose to view alcohol calorie labels.

CONCLUSIONS

In two online, hypothetical experiments there is no evidence for alcohol calorie labelling impacting consumer decisions to order alcohol or food. Given the choice, a self-selecting group of individuals who are more motivated by health concerns will view alcohol calorie labels, and in turn may be less likely to order alcohol.

Barriers and facilitators to healthy eating in disadvantaged adults living in the UK: a scoping review

In the UK people living in disadvantaged communities are less likely than those with higher socio-economic status to have a healthy diet. To address this inequality, it is crucial scientists, practitioners and policy makers understand the factors that hinder and assist healthy food choice in these individuals. In this scoping review, we aimed to identify barriers and facilitators to healthy eating among disadvantaged individuals living in the UK. Additionally, we used the Theoretical Domains Framework (TDF) to synthesise results and provide a guide for the development of theory-informed behaviour change interventions. Five databases were searched, (CINAHL, Embase, MEDLINE, PsycINFO, and Web of Science) for articles assessing healthy dietary intake of disadvantaged adults living in the UK. A total of 50 papers (34 quantitative; 16 qualitative) were included in this review. Across all studies we identified 78 barriers and 49 facilitators found to either impede and/or encourage healthy eating. Both barriers and facilitators were more commonly classified under the Environmental, Context and Resources TDF domain, with 74% of studies assessing at least one factor pertaining to this domain. Results thus indicate that context related factors such as high cost and accessibility of healthy food, rather than personal factors, such as lack of efficiency in healthy lifestyle drive unhealthy eating in disadvantaged individuals in the UK. We discuss how such factors are largely overlooked in current interventions and propose that more effort should be directed towards implementing interventions that specifically target infrastructures rather than individuals.

Is the effect of menu energy labelling on consumer behaviour equitable? A pooled analysis of twelve randomized control experiments

Menu energy labelling has been implemented as a public health policy to promote healthier dietary choices and reduce obesity. However, it is unclear whether the influence energy labelling has on consumer behaviour differs based on individuals' demographics or characteristics and may therefore produce inequalities in diet. Data were analysed from 12 randomized control trials (N = 8508) evaluating the effect of food and drink energy labelling (vs. labelling absent) on total energy content of food and drink selections (predominantly hypothetical) in European and US adults. Analyses examined the moderating effects of participant age, sex, ethnicity/race, education, household income, body mass index, dieting status, food choice motives and current hunger on total energy content of selections. Energy labelling was associated with a small reduction (f2 = 0.004, -50 kcal, p < 0.001) in total energy selected compared to the absence of energy labelling. Participants who were female, younger, white, university educated, of a higher income status, dieting, motivated by health and weight control when making food choices, and less hungry, tended to select menu items of lower energy content. However, there was no evidence that the effect of energy labelling on the amount of energy selected was moderated by any of the participants' demographics or characteristics. Energy labelling was associated with a small reduction in energy content of food selections and this effect was similar across a range of participants' demographics and characteristics. These preliminary findings suggest that energy labelling policies may not widen existing inequalities in diet.

Socioeconomic position and the effect of energy labelling on consumer behaviour: a systematic review and meta-analysis

BACKGROUND

There are well documented socioeconomic disparities in diet quality and obesity. Menu energy labelling is a public health policy designed to improve diet and reduce obesity. However, it is unclear whether the impact energy labelling has on consumer behaviour is socially equitable or differs based on socioeconomic position (SEP).

METHODS

Systematic review and meta-analysis of experimental (between-subjects) and pre-post implementation field studies examining the impact of menu energy labelling on energy content of food and/or drink selections in higher vs. lower SEP groups.

RESULTS

Seventeen studies were eligible for inclusion. Meta-analyses of 13 experimental studies that predominantly examined hypothetical food and drink choices showed that energy labelling tended to be associated with a small reduction in energy content of selections that did not differ based on participant SEP (X2(1) = 0.26, p = .610). Effect estimates for higher SEP SMD = 0.067 [95% CI: -0.092 to 0.226] and lower SEP SMD = 0.115 [95% CI: -0.006 to 0.237] were similar. A meta-analysis of 3 pre-post implementation studies of energy labelling in the real world showed that the effect energy labelling had on consumer behaviour did not significantly differ based on SEP (X2(1) = 0.22, p = .636). In higher SEP the effect was SMD = 0.032 [95% CI: -0.053 to 0.117] and in lower SEP the effect was SMD = -0.005 [95% CI: -0.051 to 0.041].

CONCLUSIONS

Overall there was no convincing evidence that the effect energy labelling has on consumer behaviour significantly differs based on SEP. Further research examining multiple indicators of SEP and quantifying the long-term effects of energy labelling on consumer behaviour in real-world settings is now required.

REVIEW REGISTRATION

Registered on PROSPERO (CRD42022312532) and OSF ( https://doi.org/10.17605/OSF.IO/W7RDB ).

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.

Is altering the availability of healthier vs. less-healthy options effective across socioeconomic groups? A mega-analysis

Background

Availability interventions have been hypothesised to make limited demands on conscious processes and, as a result, to be less likely to generate health inequalities than cognitively-oriented interventions. Here we synthesise existing evidence to examine whether the impact of altering the availability of healthier vs. less-healthy options differs by socioeconomic position.

Methods

Individual-level data (21,360 observations from 7,375 participants) from six studies (conducted online (n = 4) and in laboratories (n = 2)) were pooled for mega-analysis. Multilevel logistic regressions analysed the impact of altering the availability of healthier options on selection of a healthier (rather than a less-healthy) option by socioeconomic position, assessed by (a) education and (b) income.

Results

Participants had over threefold higher odds of selecting a healthier option when the available range was predominantly healthier compared to selections when the range offered was predominantly less-healthy (odds ratio (OR): 3.8; 95%CIs: 3.5, 4.1). Less educated participants were less likely to select healthier options in each availability condition (ORs: 0.75–0.85; all p < 0.005), but there was no evidence of differences in healthier option selection by income. Compared to selections when the range offered was predominantly less-healthy, when predominantly healthier options were available there was a 31% increase in selecting healthier options for the most educated group vs 27% for the least educated. This modest degree of increased responsiveness in the most educated group appeared only to occur when healthier options were predominant. There was no evidence of any differential response to the intervention by income.

Conclusion

Increasing the proportion of healthier options available increases the selection of healthier options across socioeconomic positions. Availability interventions may have a slightly larger beneficial effect on those with the highest levels of education in settings when healthier options predominate.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01315-y.

The impact of the consumer and neighbourhood food environment on dietary intake and obesity-related outcomes: A systematic review of causal impact studies

BACKGROUND

The food environment has been found to impact population dietary behaviour. Our study aimed to systematically review the impact of different elements of the food environment on dietary intake and obesity.

METHODS

We searched MEDLINE, Embase, PsychInfo, EconLit databases to identify literature that assessed the relationship between the built food environments (intervention) and dietary intake and obesity (outcomes), published between database inception to March 26, 2020. All human studies were eligible except for those on clinical sub-groups. Only studies with causal inference methods were assessed. Studies focusing on the food environment inside homes, workplaces and schools were excluded. A risk of bias assessment was conducted using the CASP appraisal checklist. Findings were summarized using a narrative synthesis approach.

FINDINGS

58 papers were included, 55 of which were conducted in high-income countries. 70% of papers focused on the consumer food environments and found that in-kind/financial incentives, healthy food saliency, and health primes, but not calorie menu labelling significantly improved dietary quality of children and adults, while BMI results were null. 30% of the papers focused on the neighbourhood food environments and found that the number of and distance to unhealthy food outlets increased the likelihood of fast-food consumption and higher BMI for children of any SES; among adults only selected groups were impacted - females, black, and Hispanics living in low and medium density areas. The availability and distance to healthy food outlets significantly improved children's dietary intake and BMI but null results were found for adults.

INTERPRETATION

Evidence suggests certain elements of the consumer and neighbourhood food environments could improve populations dietary intake, while effect on BMI was observed among children and selected adult populations. Underprivileged groups are most likely to experience and impact on BMI. Future research should investigate whether findings translate in other countries.

Rumination and Worry Selectively Modulate Total Calorie Consumption within an Online, Nudge Tactic Paradigm

Rumination and worry, collectively referred to as perseverative cognition, have been implicated in the increased engagement of several health risk behaviours. The current study aimed to investigate the potential influencing role of these repetitive negative thought cognitions in an online snack paradigm. Participants were randomly assigned to either an even condition (a 3:3 ratio of ≤101 kcal and >201 kcal snacks) or an uneven condition (a 4:2 ratio in favour of ≤101 kcal snacks). Upon the presentation of six images of sweet treats, participants were asked to choose the snack they most wanted to consume “right now”, before completing the Ultra-Brief Penn State Worry Questionnaire (UB-PSWQ) and the brief (5-item) Ruminative Response Scale (RRS). The results showed that the reduced availability of higher calorie snacks significantly improved both snack choice and total calorie consumption. However, despite rumination and worry having no influence on the snack type chosen, higher levels of rumination still led to significantly higher overall calorie consumption. Although, contrary to predictions, higher levels of worry conversely led to significantly lower overall calorie consumption. This study adds to the growing work in the role of perseverative cognition and food consumption, which may aid in informing public health strategies. Further exploration is needed to assess whether rumination directly induces unhealthy eating behaviours or simply exacerbates them.

Are nudging and pricing strategies on food purchasing behaviors equally effective for all? Secondary analyses from the Supreme Nudge virtual supermarket study

Nudging and pricing strategies are effective in promoting healthier purchases. However, whether the effects are equal across individuals with different personal characteristics is unknown. This exploratory study aimed to examine differential effects of nudging and pricing strategies on food purchases across individuals' levels of impulsivity, price sensitivity, decision-making styles, and food choice motives. Data from a virtual supermarket experiment where participants were exposed to five study conditions (control, nudging, pricing, salient pricing, and salient pricing with nudging) was used. Participants completed questionnaires assessing their impulsivity, price sensitivity, decision-making styles, and food choice motives. The outcome was the percentage of healthy food purchases. Effect modification was analyzed by adding interaction terms to the statistical models and post-hoc probing was conducted for statistically significant interaction terms. We used data from 400 Dutch adult participants (61.3% female, median age 30.0 years (IQR 24.0)). The effects of the nudging and pricing conditions on healthy food purchases were not modified by impulsivity, price sensitivity, decision-making styles, and the food choice motives 'health' and 'price'. Only the interactions of the food choice motive 'natural content of foods' x pricing (B = -1.02, 90%CI = -2.04; -0.01), the food choice motive 'weight control' x nudging (B = -2.15, 90%CI = -3.34; -0.95), and 'weight control' x pricing (B = -1.87, 90%CI = -3.11; -0.62) were statistically significant. Post-hoc probing indicated that nudging and/or pricing strategies were more effective in individuals who gave lower priority to these food choice motives. The effects of nudging and pricing strategies on increasing healthy food purchasing behaviors, at least in a virtual environment, do not seem to be influenced by personal characteristics and may therefore be implemented as general health promoting strategies.

Resilience Innovations and the Use of Food Order & Delivery Platforms by the Romanian Restaurants during the COVID-19 Pandemic

The COVID-19 pandemic, the blocking of activity by the government and the restrictions imposed in Romania had detrimental effects on the activity of restaurants, imposing their adaptation to new situations and generating creative innovations that caused changes in the way restaurants deliver food to consumers through food order & delivery platforms. Exploring the nature and implications of such innovations on resilience, this study analyzes their impact on the attitude and intention to use food delivery platforms by restaurant managers in Romania during the COVID-19 pandemic. Through the proposed structural model, the authors integrate innovations in resilience by joining together the new components of the established TAM model. This research was conducted on a sample of 402 restaurant managers in Romania. The data was collected based on a questionnaire, and it was analyzed with the SmartPLS3 software. The results of the study show that the four variables of innovation, namely business strategy innovations, technological innovations, financial innovations and social innovations, exert different effects on behavioral intention and attitude towards using the order & delivery platforms. The results of the study can be key points in the more efficient management of material, financial and human resources, thus improving the commercial performance of restaurants.

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.

Increasing availability of lower energy meals vs. energy labelling in virtual full-service restaurants: two randomized controlled trials in participants of higher and lower socioeconomic position

Background

There are a range of interventions designed to promote healthier food choices in full-service restaurants. However, it is unclear how these interventions affect dietary choices in people of lower and higher socioeconomic position (SEP).

Methods

A total of 2091 US participants recruited online completed Study 1 (n = 1001) and Study 2 (n = 1090). Recruitment was stratified by participant highest education level, resulting in higher SEP and lower SEP groups. In a between-subjects design, participants made hypothetical food choices (main dish, plus optional sides and desserts) from six restaurants menus in the absence vs. presence of menu energy labelling and from menus with baseline (10%) vs. increased availability (50%) of lower energy main dishes. Data were collected and analysed in 2019. Two studies were conducted in order to examine replicability and generalisability of findings across different restaurant menu types.

Results

Across both studies, increasing the availability of lower energy main menu options decreased the average energy content of the ordered main dish (− 129 kcal, 95% CI [− 139; − 119]) and total energy ordered (− 117 kcal, 95% CI [− 138; − 95]) in both higher and lower SEP participants. Energy labelling significantly reduced the energy content of ordered main dishes in higher SEP participants (− 41 kcal, 95% CI [− 54; − 29]), but not lower SEP participants (− 5 kcal, 95% CI [− 22; 11]). However, energy labelling reduced total energy ordered (− 83 kcal, 95% CI [− 105; − 60]) irrespective of SEP.

Conclusions

In two virtual experiments, increasing the availability of lower energy restaurant main menu options impacted on main menu dish choice and decreased total energy ordered irrespective of SEP. Energy labelling had a less pronounced effect on total energy ordered and had a larger impact on the energy content of main menu dish choice in higher as opposed to lower SEP participants.

Trial registration

Clinicaltrials.gov NCT04336540 retrospectively registered (7 April, 2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11007-0.

The effect of calorie and physical activity equivalent labelling of alcoholic drinks on drinking intentions in participants of higher and lower socioeconomic position: An experimental study

OBJECTIVES

The primary objective of the study was to examine the effect of calorie labelling and physical activity equivalence labelling of alcoholic drinks on drinking intentions in participants of lower and higher socioeconomic position (SEP).

METHODS

Participants (N = 1,084) of higher and lower SEP were recruited into an online study and randomized into one of three drink label conditions; Control (standard alcohol labelling), kcal labelling (standard labelling plus drink kilocalorie information), or kcal + PACE labelling (standard labelling and kilocalorie information, plus information on physical activity needed to compensate for drink calories). After viewing drink labels, participants reported alcohol drinking intentions. Participants also completed measures of alcoholic drink energy content estimation, beliefs about how calorie labelling would affect health behaviour and support for calorie labelling of alcoholic drinks.

RESULTS

kcal labelling (d = 0.31) and kcal + PACE labelling (d = 0.38) conditions had significantly lower drinking intentions compared to the control condition (ps < .001). There was no evidence that effect of labelling condition on drinking intentions was moderated by SEP. A subset of participants also reported that they believed calorie labelling would be likely to positively change their eating and exercise behaviour. Estimates of the energy content of alcoholic drinks tended to be inaccurate and the majority of participants supported the introduction of calorie labelling on alcoholic drinks.

CONCLUSIONS

Calorie labelling of alcoholic drinks resulted in small reductions to intended drinking and testing of the effect calorie labelling has on behaviour in real-world settings is now warranted.

The energy and nutritional content of snacks sold at supermarkets and coffee shops in the UK

BACKGROUND

Snacking is associated with a higher daily energy intake and dietary guidelines recommend snacks of no more than 200 kcal for adults and 100 kcal for children. The present study examines the energy content, nutritional quality and price of single-serving snack food products sold by major supermarket and coffee shop chains in the UK.

METHODS

Energy content, nutritional content and price of single-serving snack products were recorded in 2019 via the websites of 14 major chains (seven supermarkets; seven coffee shops).

RESULTS

The mean energy content of all eligible snack products (n = 2283) was 186 kcal [95% confidence interval (CI) = 182-190]. The mean energy content of the snack products sold at coffee shops (n = 379; 282 kcal [95% CI = 269-295]) was significantly higher than the energy content of the snack products sold at supermarkets (n = 1904; 167 kcal [95% CI = 164-170]). Seventy nine % of supermarket snacks exceeded energy recommendations for children and 32% for adults. In coffee shops, 91% exceeded recommendations for children and 73% for adults. Forty one % of snacks were high in fat, 42% were high in saturated fat, 39% were high in sugar and 7% were high in salt. Cheaper snack products were more likely to be of lower nutritional quality.

CONCLUSIONS

The high proportion of snack products that do not meet public health recommendations for energy content may contribute to the association between snacking and increased energy intake. Public health measures to increase the availability and reduce the price of snack products that meet public health energy content recommendations may reduce population-level obesity.

Individual differences and moderating participant characteristics in the effect of reducing portion size on meal energy intake: Pooled analysis of three randomized controlled trials

Portion size impacts on the amount of energy consumed during a meal. However, research findings on participant characteristics that moderate the effect of portion size on energy intake are mixed. Using data pooled across three randomized control trials, we examined the impact of reducing meal portion size on meal energy intake in 111 adult participants varying in sex (55 M, 56 F), body weight (BMI range = 19-42) and a broad range of participant characteristics, including usual portion size, restrained, emotional and external eating, satiety responsiveness, plate clearing tendencies, concerns about wasting food and self-control. In each trial, a repeated-measures design was used and participants consumed three ad-libitum lunchtime meals differing in portion size; large-normal portion size condition (100%) vs. small-normal portion size condition (~ 75%) vs. smaller than normal portion size condition (~ 50%). In mixed ANOVAs, we did not find convincing evidence that any participant characteristic reliably moderated the impact that reducing portion size had on energy intake. For the majority of participants energy intake decreased when portion size was reduced and it was more common for participants to consistently reduce their energy intake than consume a similar amount when portion size was reduced. We also found little evidence that a sub-group of participants existed whose energy intake was consistently resistant to portion size reductions. Portion size may be a universal driver of energy intake, as reducing meal portion size appears to decrease meal energy intake among most people. Food portion downsizing may therefore be an equitable intervention approach to reducing population level energy intake.

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.