The impact of nutritional labels and socioeconomic status on energy intake. An experimental field study

The neural model of front-of-package label processing

Front-of-package (FOP) labels have been adopted in many countries to battle the obesity pandemic and its serious health consequences by providing clearer and easier-to-understand nutrition and health information. The effectiveness of FOP labels has been generally confirmed, with some contextual and individual factors modifying their effectiveness. Existing theories (eg, the dual-process theory) and shifting priorities for self-control, provide some explanations for the FOP label effect. However, the cognitive and neural mechanisms underlying the processing of FOP labels remain unknown. Here, a new model, namely, the neural model of FOP label processing, has been proposed to fill this gap by providing an integrated account of FOP label processing while simultaneously considering multiple important situational and individual factors in the same framework. This neural model is built on the core eating network (ie, the ventral reward pathway and the dorsal control pathway) for food cue processing and actual food consumption. The new model explains how FOP labels may facilitate attention, influence the core eating network, and thus alter food choices. It also demonstrates how motivation may modify FOP label processing in 2 ways: affecting attention (the indirect way) and changing the process of evaluating the food (the direct way). It further explains how some contextual and individual factors (eg, ego depletion, time pressure, and health knowledge) influence the process. Thus, the neural model integrates evidence from behavioral, eye-tracking, and neuroimaging studies into a single, integrated account, deepening understanding of the cognitive and neural mechanisms of FOP label processing. This model might facilitate consensus on the most successful FOP label. Moreover, it could provide insights for consumers, food industries, and policy makers and encourage healthy eating behaviors.

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.

Are Front-of-Pack Nutrition Labels Influencing Food Choices and Purchases, Diet Quality, and Modeled Health Outcomes? A Narrative Review of Four Systems

Front-of-Pack Nutrition labels (FOPNLs) aim to improve consumers' food purchases and prompt product reformulation by the food and beverage industry. Despite their widespread use, the effectiveness of FOPNL in achieving these goals is still a matter of debate. This review has gathered 65 original studies exploring the performances of four widely used FOPNLs (Multiple Traffic Light, Warning signs, Nutri-Score and Health Star Rating). Although FOPNLs have been associated with healthier food purchases, the magnitude of improvements was small and dependent on study settings. Any associated health effects were modeled rather than observed. None of the four FOPNLs clearly outperformed the other ones on any outcome. Few studies dealt with the impact of FOPNL on product reformulation. Some of those studies, but not all, found small reductions in energy, sodium, sugar and saturated fat content of foods in some food categories. Although global trends point to a small favorable effect of FOPNL, this conclusion is subject to caution since the evidence is inconsistent and comes from a wide variety of contexts and study designs. There remain numerous research gaps, notably with regard to the optimal characteristics of FOPNLs, the durability of FOPNL effects on consumer behaviors, and any possible unexpected consequences.

The effect of orthorexia nervosa on food label reading habits among university students

PURPOSE

This observational cross-sectional study aimed to evaluate university students' food label reading habits with and without orthorexia nervosa (ON) tendency.

METHODS

Data were collected online with a questionnaire. The questionnaire form included sociodemographic variables, the ORTO-11 scale, the reading frequency of some components on the food label, and the evaluation of some opinions about the food label. The obtained data were evaluated with SPSS 25.0 statistical package program and GraphPad Prism program.

RESULTS

A total of 674 university students (mean age: 21.03 ± 2.43 years), 537 women (79.7%) and 137 men (20.3%) were included in the study. It was determined that individuals with ON tendency read some nutrients, content information, serving size, health information, instructions for use, additives and brand more frequently compared to individuals without ON tendency (p < 0.05). At the same time, it was determined that individuals with ON tendency were more likely to agree with the idea that reading food labels is important for a healthy diet, compared to individuals with normal eating behavior (p < 0.001).

CONCLUSION

The study findings show that individuals with ON tendency have a higher habits of reading food labels compared to individuals with normal eating behavior. To reach a decision on this issue and to determine the diagnostic criteria for ON, future studies should be conducted on different groups and samples with higher participation, as well as studies using different screening tools to determine the tendency for ON.

LEVEL OF EVIDENCE

V, Cross-sectional descriptive study.

The effect of energy and fat content labeling on food consumption pattern: a systematic review and meta-analysis

CONTEXT

Consumption of high-energy food has increased globally, thereby leading to an increase in many diseases. One strategy for addressing this is to make people aware of their energy intake through energy and fat labels. However, the effectiveness of this remains debatable.

OBJECTIVE

This review aims to pool the mixed outcomes of recent studies assessing the effect of energy and fat content labeling on food consumption pattern.

DATA SOURCES

Google Scholar, MEDLINE, and Cochrane Library databases were searched. Randomized controlled and quasi-experimental controlled trials published from 2014 to 2019 were included.

DATA EXTRACTION

Two reviewers screened 413 abstracts independently. Qualitative and quantitative data was extracted from 10 articles; meta-analysis was carried out on 6 of those studies.

RESULTS

The majority of the included papers were conducted in the regions of America, the Western Pacific, and Europe. Overall, the 6 studies claimed that labeling did not reduce the consumption of energy or fat. However, meta-analysis showed that fat and energy content labeling of food had a statistically significant effect on consumption. Subgroup analysis showed no difference with respect to types of labels, ie, context labeling vs traffic-light labeling, but energy content labels seemed to be more effective than fat content labels in influencing healthy food choices.

CONCLUSION

Energy and fat content labeling were shown to reduce the consumption of each significantly. However, the outcome was influenced by the study setting and the population concerned. There is a need for research in other regions in order to assess the global effectiveness of nutrition labels on food consumption.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020172675.

Equity Effects of Dietary Nudging Field Experiments: Systematic Review

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

Interventions using behavioural insights to influence children's diet-related outcomes: A systematic review

The global prevalence of children with overweight and obesity continues to rise. Obesity in childhood has dire long-term consequences on health, social and economic outcomes. Promising interventions using behavioural insights to address obesity in childhood have emerged. This systematic review examines the effectiveness and health equity implications of interventions using behavioural insights to improve children's diet-related outcomes. The search strategy included searches on six electronic databases, reference lists of previous systematic reviews and backward searching of all included studies. One-hundred and eight papers describing 137 interventions were included. Interventions using behavioural insights were effective at modifying children's diet-related outcomes in 74% of all included interventions. The most promising approaches involved using incentives, changing defaults and modifying the physical environment. Information provision alone was the least effective approach. Health equity implications were rarely analysed or discussed. There was limited evidence of the sustainability of interventions-both in relation to their overall effectiveness and cost-effectiveness. The limited evidence on health equity, long-term effectiveness and the cost-effectiveness of these interventions limit what can be inferred for policymakers. This review synthesises the use of behavioural insights to improve children's diet-related outcomes, which can be used to inform future interventions.

Effectiveness of interpretive front-of-pack nutritional labelling schemes on the promotion of healthier food choices: a systematic review

AIMS

Interpretive front-of-package nutrition labelling can contribute to healthier food habits. This systematic review aimed to examine the effectiveness of interpretive front-of-package nutrition labelling schemes on consumers' food choices, namely at the moment of food purchase, and to analyse if this potential front-of-package nutrition labelling's effect varies according to different socioeconomic groups.

METHODS

Electronic databases (Cochrane Library, PubMed, Scopus, and Web of Science) search was performed to identify peer-reviewed articles describing longitudinal studies evaluating the effect of front-of-package nutrition labelling schemes on consumers' food choices, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-Equity 2012 Extension guidelines. No publication-period or language restrictions were applied. PROGRESS-Plus framework was used to report if and how socioeconomic factors were considered in analyses of front-of-package nutrition labelling-related interventions' effect.

RESULTS

Nine studies were selected for narrative synthesis (seven randomized controlled trials and two cross-over trials). When compared with no-interpretive-label conditions, front-of-package nutrition labelling showed a positive impact for nutritional content understanding, healthiness perception of products, selection of products with better nutritional quality, and purchase intention. However, there is no robust evidence of superiority of a specific front-of-package nutrition labelling scheme's effect, neither on consumers' understanding of nutritional content nor on food choices. An evaluation of the studies following the PROGRESS-Plus framework revealed that socioecononomic status and education were the most frequently used dimensions, when assessing the effect of interpretative front-of-pack nutrition labels. More evidence is necessary to determine the role of front-of-pack nutrition labels in decreasing inequalities between different population subgroups, namely among the most vulnerable subgroups, on the promotion of healthy food choices.

CONCLUSION

Well controlled longitudinal studies, following a real-world evidence approach, are needed to clarify front-of-package nutrition labelling's impact on consumers' food choices, namely at purchase points, taking into account the most vulnerable population subgroups, such as those with lower literacy and/or financial resources.

Influence of the nutrition and health information presented on food labels on portion size consumed: a systematic review

Context

In recent decades, portion sizes have increased significantly. Although previous research indicates that food labels impact on product choice and healthiness perception, their impact on portion sizes consumed is less clear.

Objective

This systematic review examined whether food label information influenced portion size consumption.

Data sources

A search of 7 major electronic databases for studies published from 1980 to April 2016 was conducted.

Data extraction

Two reviewers independently screened 11 128 abstracts. Data were extracted from 32 articles (comprising 36 studies).

Results

Based on the test food used, the overall effects were found to be: no effect, a positive effect, or a negative effect. Labels displaying energy content (n = 15 studies, 17 effects) and fat content information (n = 13 studies, 14 effects) were evaluated most commonly, with exercise equivalent labels evaluated least (n = 2 studies, 2 effects).

Conclusions

Nutrition and health information presented on food labels has varying impacts on portion sizes consumed, from increased to decreased intake. Recommendations for future research include evaluating more recent food label types and achieving more consistent reporting standards.

5-a-day fruit and vegetable food product labels: reduced fruit and vegetable consumption following an exaggerated compared to a modest label

BACKGROUND

Food product labels based on the WHO 5-a-day fruit and vegetable (FV) message are becoming increasingly common, but these labels may impact negatively on complementary or subsequent FV consumption. This study aimed to investigate the impact of a '3 of your 5-a-day' versus a '1 of your 5-a-day' smoothie product label on subsequent FV consumption.

METHODS

Using an acute experimental design, 194 participants (90 males, 104 females) were randomised to consume a smoothie labelled as either '3 of your 5-a-day' (N = 97) or '1 of your 5-a-day' (N = 97) in full, following a usual breakfast. Subsequent FV consumption was measured for the rest of the day using 24-h recall. Usual FV consumption was also assessed via 24-h recall for the day before the study.

RESULTS

Regression analyses revealed a significantly lower subsequent FV consumption following smoothies displaying the '3 of your 5-a-day' label compared to the '1 of your 5-a-day' label (Beta = - 0.15, p = 0.04). Secondary analyses revealed these effects to be driven mainly by changes to consumption in usual high FV consumers, in females and in vegetable as opposed to fruit consumption.

CONCLUSIONS

These findings demonstrate a role for label information in food intake, and the potential negative impacts of an exaggerated food product label on healthy food consumption and healthy dietary profiles.

Nutritional labelling for healthier food or non-alcoholic drink purchasing and consumption

BACKGROUND

Nutritional labelling is advocated as a means to promote healthier food purchasing and consumption, including lower energy intake. Internationally, many different nutritional labelling schemes have been introduced. There is no consensus on whether such labelling is effective in promoting healthier behaviour.

OBJECTIVES

To assess the impact of nutritional labelling for food and non-alcoholic drinks on purchasing and consumption of healthier items. Our secondary objective was to explore possible effect moderators of nutritional labelling on purchasing and consumption.

SEARCH METHODS

We searched 13 electronic databases including CENTRAL, MEDLINE and Embase to 26 April 2017. We also handsearched references and citations and sought unpublished studies through websites and trials registries.

SELECTION CRITERIA

Eligible studies: were randomised or quasi-randomised controlled trials (RCTs/Q-RCTs), controlled before-and-after studies, or interrupted time series (ITS) studies; compared a labelled product (with information on nutrients or energy) with the same product without a nutritional label; assessed objectively measured purchasing or consumption of foods or non-alcoholic drinks in real-world or laboratory settings.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of bias' tool and GRADE to assess the quality of evidence. We pooled studies that evaluated similar interventions and outcomes using a random-effects meta-analysis, and we synthesised data from other studies in a narrative summary.

MAIN RESULTS

We included 28 studies, comprising 17 RCTs, 5 Q-RCTs and 6 ITS studies. Most (21/28) took place in the USA, and 19 took place in university settings, 14 of which mainly involved university students or staff. Most (20/28) studies assessed the impact of labelling on menus or menu boards, or nutritional labelling placed on, or adjacent to, a range of foods or drinks from which participants could choose. Eight studies provided participants with only one labelled food or drink option (in which labelling was present on a container or packaging, adjacent to the food or on a display board) and measured the amount consumed. The most frequently assessed labelling type was energy (i.e. calorie) information (12/28).Eleven studies assessed the impact of nutritional labelling on purchasing food or drink options in real-world settings, including purchases from vending machines (one cluster-RCT), grocery stores (one ITS), or restaurants, cafeterias or coffee shops (three RCTs, one Q-RCT and five ITS). Findings on vending machines and grocery stores were not interpretable, and were rated as very low quality. A meta-analysis of the three RCTs, all of which assessed energy labelling on menus in restaurants, demonstrated a statistically significant reduction of 47 kcal in energy purchased (MD -46.72 kcal, 95% CI -78.35, -15.10, N = 1877). Assuming an average meal of 600 kcal, energy labelling on menus would reduce energy purchased per meal by 7.8% (95% CI 2.5% to 13.1%). The quality of the evidence for these three studies was rated as low, so our confidence in the effect estimate is limited and may change with further studies. Of the remaining six studies, only two (both ITS studies involving energy labels on menus or menus boards in a coffee shop or cafeteria) were at low risk of bias, and their results support the meta-analysis. The results of the other four studies which were conducted in a restaurant, cafeterias (2 studies) or a coffee shop, were not clearly reported and were at high risk of bias.Seventeen studies assessed the impact of nutritional labels on consumption in artificial settings or scenarios (henceforth referred to as laboratory studies or settings). Of these, eight (all RCTs) assessed the effect of labels on menus or placed on a range of food options. A meta-analysis of these studies did not conclusively demonstrate a reduction in energy consumed during a meal (MD -50 kcal, 95% CI -104.41, 3.88, N = 1705). We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.Six laboratory studies (four RCTs and two Q-RCTs) assessed the impact of labelling a single food or drink option (such as chocolate, pasta or soft drinks) on energy consumed during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant difference in energy (kcal) consumed (SMD 0.05, 95% CI -0.17 to 0.27, N = 732). However, the confidence intervals were wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.There was no evidence that nutritional labelling had the unintended harm of increasing energy purchased or consumed. Indirect evidence came from five laboratory studies that involved mislabelling single nutrient content (i.e. placing low energy or low fat labels on high-energy foods) during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant increase in energy (kcal) consumed (SMD 0.19, 95% CI -0.14to 0.51, N = 718). The effect was small and the confidence intervals wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence from these studies as very low, providing very little confidence in the effect estimate.

AUTHORS' CONCLUSIONS

Findings from a small body of low-quality evidence suggest that nutritional labelling comprising energy information on menus may reduce energy purchased in restaurants. The evidence assessing the impact on consumption of energy information on menus or on a range of food options in laboratory settings suggests a similar effect to that observed for purchasing, although the evidence is less definite and also of low quality.Accordingly, and in the absence of observed harms, we tentatively suggest that nutritional labelling on menus in restaurants could be used as part of a wider set of measures to tackle obesity. Additional high-quality research in real-world settings is needed to enable more certain conclusions.Further high-quality research is also needed to address the dearth of evidence from grocery stores and vending machines and to assess potential moderators of the intervention effect, including socioeconomic status.

What do we know about the effects of exposure to 'Low alcohol' and equivalent product labelling on the amounts of alcohol, food and tobacco people select and consume? A systematic review

Background

Explicit labelling of lower strength alcohol products could reduce alcohol consumption by attracting more people to buy and drink such products instead of higher strength ones. Alternatively, it may lead to more consumption due to a ‘self-licensing’ mechanism. Equivalent labelling of food or tobacco (for example “Low fat” or “Low tar”) could influence consumption of those products by similar mechanisms. This systematic review examined the effects of ‘Low alcohol’ and equivalent labelling of alcohol, food and tobacco products on selection, consumption, and perceptions of products among adults.

Methods

A systematic review was conducted based on Cochrane methods. Electronic and snowball searches identified 26 eligible studies. Evidence from 12 randomised controlled trials (all on food) was assessed for risk of bias, synthesised using random effects meta-analysis, and interpreted in conjunction with evidence from 14 non-randomised studies (one on alcohol, seven on food and six on tobacco). Outcomes assessed were: quantities of the product (i) selected or (ii) consumed (primary outcomes - behaviours), (iii) intentions to select or consume the product, (iv) beliefs associated with it consumption, (v) product appeal, and (vi) understanding of the label (secondary outcomes – cognitions).

Results

Evidence for impacts on the primary outcomes (i.e. amounts selected or consumed) was overall of very low quality, showing mixed effects, likely to vary by specific label descriptors, products and population characteristics. Overall very low quality evidence suggested that exposure to ‘Low alcohol’ and equivalent labelling on alcohol, food and tobacco products can shift consumer perceptions of products, with the potential to ‘self-licence’ excess consumption.

Conclusions

Considerable uncertainty remains about the effects of labels denoting low alcohol, and equivalent labels, on alcohol, food and tobacco selection and consumption. Independent, high-quality studies are urgently needed to inform policies on labelling regulations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3956-2) contains supplementary material, which is available to authorized users.

Impact of food labelling systems on food choices and eating behaviours: a systematic review and meta-analysis of randomized studies

Food labels are considered a crucial component of strategies tackling unhealthy diets and obesity. This study aims at assessing the effectiveness of food labelling in increasing the selection of healthier products and in reducing calorie intake. In addition, this study compares the relative effectiveness of traffic light schemes, Guideline Daily Amount and other food labelling schemes. A comprehensive set of databases were searched to identify randomized studies. Studies reporting homogeneous outcomes were pooled together and analysed through meta-analyses. Publication bias was evaluated with a funnel plot. Food labelling would increase the amount of people selecting a healthier food product by about 17.95% (confidence interval: +11.24% to +24.66%). Food labelling would also decrease calorie intake/choice by about 3.59% (confidence interval: -8.90% to +1.72%), but results are not statistically significant. Traffic light schemes are marginally more effective in increasing the selection of healthier options. Other food labels and Guideline Daily Amount follow. The available evidence did not allow studying the effects of single labelling schemes on calorie intake/choice. Findings of this study suggest that nutrition labelling may be an effective approach to empowering consumers in choosing healthier products. Interpretive labels, as traffic light labels, may be more effective.