Physical activity equivalent labeling vs. calorie labeling: a systematic review and meta-analysis

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.

Food for thought: Reinforced learning and recall of physical activity calorie equivalent (PACE) and numerical calorie content in an associative learning task

Calorie overconsumption has been proposed as a critical contributing factor to rising obesity rates. To combat this health issue, governments and policymakers have suggested implementing numerical caloric content labels. Alternatively, physical activity calorie equivalent (PACE) labels are being proposed as an easier-to-understand metric, representing the amount of physical activity required to burn off calorie content. This study examined individuals' ability to correctly estimate either the numerical caloric content or the PACE values of food images in an associative learning task. Moreover, it assessed whether this knowledge was learned and retained over time. One hundred and ninety-one participants were instructed to estimate either the numerical caloric content or PACE values of thirty food images. To facilitate learning, feedback on the correct number of calories or PACE values was provided during the first session (Time 1). To assess retention, people re-estimated numerical caloric content or PACE values of the same food pictures three days later (Time 2) and seven days later (Time 3), where feedback was not provided. Results showed that participants in both groups improved their estimations using feedback, with people being consistently more accurate when estimating numerical calorie content. Yet, our results also suggest that participants consolidated their knowledge of PACE values over time. Finally, our findings show that hunger moderates individuals' estimation ability, where hungrier people are less accurate than satiated ones. The results contribute to our understanding of how consumers process, estimate, and learn PACE labels versus numerical caloric content, and provide valuable information for researchers and policymakers to develop and implement nutritional labels as a health strategy.

Designing a new physical activity calorie equivalent food label and comparing its effect on caloric choices to that of the traffic light label among mothers: a mixed-method study

Objective

We designed a new type of 'physical activity calorie equivalent' (PACE) food label in Iran to compare its effect with that of the traffic light food label (TLL) on caloric choices.

Design

Mixed-method study.

Participants

Mothers of school children between the ages of 6-12 years.

Setting

In the qualitative phase, 10 focus group discussions (FGDs) were conducted with various groups of mothers, and two FGDs were conducted with food science and nutrition experts to design a new PACE label. In the quantitative phase, 496 mothers were randomly assigned to five groups: (1) no nutrition label, (2) current TLL, (3) current TLL + educational brochure, (4) PACE label, and (5) PACE label + brochure. Samples of dairy products, beverages, cakes, and biscuits were presented. ANOVA and multiple linear regressions were applied to examine the association between label types and calories of the selected products as our main outcome.

Results

The mothers' perspectives were classified into two sub-themes, the PACE label's facilitators and barriers. The new PACE label's characteristics were divided into two subcategories: (a) appearance, and (b) nutritional information, including 14 codes. In the quantitative section, mean calories of the selected foods were lowest in the TLL + brochure group (831.77 kcal; 95% CI: 794.23-869.32), and highest in the PACE label group (971.61; 95% CI: 926.37-1016.84).

Conclusion

The new PACE label was a combination of PACE, TLL, and warning labels. It did not significantly affect lower caloric choice, however, the TLL + brochure option was effective in choosing foods with fewer calories.Clinical trial registration: The study was registered in the Iranian Registry of Clinical Trials 23 (IRCT20181002041201N1).

Effects of 4 Interpretive Front-of-Package Labeling Systems on Hypothetical Beverage and Snack Selections: A Randomized Clinical Trial

Importance

Policymakers and researchers have proposed a variety of interpretative front-of-package food labeling systems, but it remains unclear which is most effective at encouraging people to choose healthier foods and beverages, including among people with less education.

Objective

To test the effects of 4 interpretative front-of-package food labeling systems on the healthfulness of beverage and snack selections, overall and by education level.

Design, Setting, and Participants

This randomized clinical trial of a national sample of US adults 18 years and older was conducted online from November 16 to December 3, 2022.

Intervention

Participants were randomized to view products with 1 of 5 food labeling systems, including control (calorie labels only) or 1 of 4 interpretative labeling systems: green ("choose often") labels added to healthy foods; single traffic light labels added to healthy, moderately healthy, and unhealthy foods; physical activity calorie equivalent labels added to all products; and nutrient warning labels added to products high in calories, sugar, saturated fat, or sodium. All conditions had calorie labels on all products.

Main Outcomes and Measures

Participants selected 1 of 16 beverages and 1 of 16 snacks that they wanted to hypothetically purchase. The primary outcomes were calories selected from beverages and from snacks. Secondary outcomes included label reactions and perceptions.

Results

A total of 7945 participants completed the experiment and were included in analyses (4078 [51%] female, 3779 [48%] male, and 88 [1%] nonbinary or another gender; mean [SD] age, 47.5 [17.9 years]). Compared with the control arm, exposure to the green (average differential effect [ADE], -34.2; 95% CI, -42.2 to -26.1), traffic light (ADE, -31.5; 95% CI, -39.5 to -23.4), physical activity (ADE, -39.0; 95% CI, -47.0 to -31.1), or nutrient warning labels (ADE, -28.2; 95% CI, -36.2 to -20.2) led participants to select fewer calories from beverages (all P < .001). Similarly, compared with the control label, exposure to the green (ADE, -12.7; 95% CI, -17.3 to -8.2), traffic light (ADE, -13.7; 95% CI, -18.2 to -9.1), physical activity (ADE, -18.5; 95% CI, -23.1 to -13.9), or nutrient warning labels (ADE, -14.2; 95% CI, -18.8 to -9.6) led participants to select fewer calories from snacks (all P < .001). These effects did not differ by education level. The green labels were rated as less stigmatizing than the other interpretative systems but otherwise generally received the least favorable label reactions and perceptions (eg, elicited less attention, were perceived as less trustworthy), while the nutrient warnings and physical activity labels received the most favorable ratings.

Conclusions and Relevance

In this randomized clinical trial of front-of-package food labeling systems, all 4 interpretative labeling systems reduced calories selected from beverages and from snacks compared with calorie labels, with no differences by education level.

Trial Registration

ClinicalTrials.gov Identifier: NCT05432271.

Customer support for nudge strategies to promote fruit and vegetable intake in a university food service

Background

Diverse nudges, also known as choice architectural techniques, have been found to increase fruit and vegetable (FV) selection in both lab and field studies. Such strategies are unlikely to be adopted in mass eating settings without clear evidence of customer support; confirmation in specific contexts is needed. Inspired by the Taxonomy of Choice Architecture, we assessed support for eight types of nudging to increase the choice of FV-rich foods in a university food service. We also explored whether and to what extent nudge support was associated with perceived effectiveness and intrusiveness.

Methods

An online survey was conducted with students who used on-campus cafeterias. Multiple recruitment methods were used. Participants were given 20 specific scenarios for increasing FV selection and asked about their personal support for each nudge, as well as perceived intrusiveness and effectiveness. General beliefs about healthy eating and nudging were also measured. Results were assessed by repeated measures ANOVA for the 8 nudge types.

Results

All nudge scenarios achieved overall favourable ratings, with significant differences among different types of nudging by the 298 respondents. Changing range of options (type B3) and changing option-related consequences (type B4) received the highest support, followed by changing option-related effort (type B2) and making information visible (type A2). Translating information (type A1), changing defaults (type B1) and providing reminders or facilitating commitment (type C) were less popular types of nudging. Providing social reference points (type A3) was least supported. Support for nudge types was positively associated with the belief that food services have a role in promoting healthy eating, perceived importance of FV intake, trustworthiness of the choice architect and female gender. Lastly, support for all types of nudges was positively predicted by perceived effectiveness of each nudge and negatively predicted by perceived intrusiveness above and beyond the contribution of general beliefs about healthy eating and nudging.

Conclusions

Findings from the current study indicate significant differences in support for nudge techniques intended to increase FV selection among university cafeteria users. These findings offer practical implications for food service operators as well as public health researchers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13054-7.

The Negative Effects of Long Time Physical Activity Calorie Equivalent Labeling on Purchase Intention for Unhealthy Food

(1) Background: Obesity has become a global epidemic that arouse much attention from governments, companies and scholar. Physical activity calorie equivalent (PACE) labels are introduced as a more effective nudge invention on less-calorie ordering. However, the effects of PACE labels are controversial in previous literature, thus, the research objective is to explore the effects of different PACE labels and furtherly to explore the underlying psychological mechanism; (2) Methods: Across four scenario-based experiments, involving potato chips, chocolate and cookies, this study manipulated the three calorie-information labeling (standard calorie label, long time PACE and short time PACE labels). Meanwhile, the mediating mechanism of the effects involving anticipatory guilt and the moderation effects between consumers’ future self-continuity and PACE labels are also measured; (3) Results: Results show that compared with the short time PACE and calorie labels, the longtime PACE labels have more negative influence on consumers’ purchase intention for unhealthy food. What’s more, the anticipatory guilt has negative effect of PACE labels as consumers are often prone to feeling guilty in the process of unhealthy food consumption. In addition, individuals with high future self-continuity have higher self-control and take more consideration of future outcomes, they are reluctant to choose unhealthy food than others; (4) Conclusions: Unhealthy food with a long time PACE label has more negative effect on consumers’ purchase intention rather than a short time PACE label. At the same time, companies that produce healthy foods should actively participate in the movement to label calories through the PACE labels.

Is Calorie Labeling on Menus Related to Weight Disturbances among Females in Saudi Arabia?

Calorie labeling is a recent initiative from the Saudi Food and Drug Authority (SFDA) aimed to reduce the prevalence of noncommunicable diseases (NCDs) by influencing people to make healthier food choices when they eat out and can also help people with weight disturbances to be more aware of their calorie intake. The present study aimed to investigate the association between the use of calorie labeling on restaurant menus, calorie intake, weight concern, body weight perception, and weight-control behaviors among young women. A quasi-experimental study was conducted among female students at a university restaurant. Participants were assigned to two groups: food menus with (experimental group) and without (control group) calorie labeling. The logistic regression model assessed the predictors of using calorie information separately for the experimental and control groups. Calorie labeling had a significant effect on reducing calorie consumption in the experimental group by 59 calories compared to the control group. The higher weight concern in the control group (OR = 0.410; 95% CI 0.230-0.730; P ≤ 0.002) was a predictor for using calorie information. The experimental group had higher weight concern (OR = 1.530; 95% CI 1.107-2.115; P ≤ 0.01) and body weight perception (OR = 4.230; 95% CI 1.084-6.517; P ≤ 0.038) and lower calorie intake (OR = 1.005; 95% CI 1.001-6.517; P ≤ 0.008) predictors for using calorie information. Weight-control behaviors did not significantly predict the use of calorie information in the groups. Calorie labeling might increase the weight disturbances among young females. More investigation is needed across various populations to gain a better understanding of calorie labeling as an effective food choice among people who are vulnerable to weight disturbances or already have weight disorders.

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.

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.

PACE Labels on Healthy and Unhealthy Snack Products in a Laboratory Shopping Setting: Perception, Visual Attention, and Product Choice

Informative food labels are one way to increase nutritional awareness in society and can essentially help individuals maintain balanced dietary practices. Nonetheless, making food labels ‘informative’, in the sense of applicability, is not always easy. Physical activity calorie equivalent (PACE) food labeling is one approach to achieve this goal. Yet, it is neither understood how consumers perceive PACE labels, nor how effective they are in regards to healthy food choices. Moreover, it is of interest to assess the perception of real products in close-to-realistic environments. Therefore, this study examined a simulated purchase situation and consumers’ visual attention on PACE labels—on 20 different real snack products with varying health values. In a laboratory-shopping environment, the gaze behaviors of 91 consumers were examined with a head-mounted eye-tracker. In regards to perception, it was elucidated that every participant noticed at least one PACE label. On average 1.39 PACE label fixations on different products were counted with a mean fixation duration of 0.55 s and a mean time to first fixation of 22.46 s. On average, 22.9% of the participants viewed the PACE labels at least once, but the intensity and duration varied greatly between the different products; ’healthier products’ attracted more visual attention than ‘unhealthier products’. In regards to health choice, it became obvious that the choices observed were rather healthy and PACE labels attracted attention. This may have been especially true for participants with little involvement in physical activity and health behavior, which may have been the main target group. Hence, catchy, communicable PACE labels, as well as balanced product offerings may facilitate more healthy food choices. The real-world laboratory setting offered valuable insights, which should be followed-up on.

The Differential Effects of Physical Activity Calorie Equivalent Labeling on Consumer Preferences for Healthy and Unhealthy Food Products: Evidence from a Choice Experiment

Background: Since numerical calorie labels have limited effects on less-calorie food ordering, an alternative called physical activity calorie equivalent (PACE) labels, which exhibit calories using visible symbols and the minutes of exercise to burn off the calories, may be more effective in reducing calories ordered. Methods: By using a choice experiment (CE) approach, the aims of this study were to estimate the effects of PACE labels on consumer preferences for healthy and unhealth food. Red date walnuts and potato chips were used as the representatives of healthy and unhealthy foods respectively in this study. Moreover, future time perspective (FTP) is an individual trait variable of consumers, which has been recognized as a significant driver of healthy behaviors. We also included FTP into the interaction with PACE labels. Results: Firstly, the results were opposite between the healthy and unhealthy food groups. Respondents showed significantly more positive attitudes toward red date walnuts (i.e., healthy food) with PACE labels, while they showed significantly more negative preferences for chips (i.e., unhealthy food) with PACE labels. Secondly, people with higher FTP are preferred red date walnuts with PACE labels, while PACE labels on chips could undermine the preferences of respondents with higher FTP. Thirdly, we found that women (vs. men) were less inclined to choose healthy food with standard calorie labels and labels showing the minutes of running to burn off the calories, as well as that the elderly (vs. younger) people in the healthy food group preferred the labels showing the minutes of running to burn off the calories. People with a higher body mass index (BMI) were reluctant to purchase walnuts with the information about the minutes of walking. Conclusions: Results from this study showed that PACE labels have significant effects on consumers’ preferences for food products.

Potential effect of different nutritional labels on food choices among mothers: a study protocol

BACKGROUND

The prevalence of non-communicable diseases (NCDs) is increasing in the world. Healthy food choice and adequate physical activity are key factors in preventing NCDs. Food labeling is a strategy that can inform consumers to choose healthier foods at the point of purchase. In this study, we intend to examine the status of existing labels and to clarify their strengths and weaknesses. Then, for the first time in Iran, we will design a type of physical activity equivalent calorie label and will test it on some food groups of packaged products including dairy products, sweetened beverages, cakes, and biscuits.

METHODS

This study will be conducted in two phases. In phase 1, nutrition fact labels and traffic light labels will be assessed through focus group discussions and interviews among different groups of mothers, industrialists and nutrition and food industry specialists as to determine strengths and weaknesses of the current labels on packaged products. Then, the initial layout of the physical activity calorie equivalent label will be drawn with respect to the viewpoints received from mothers. Thereafter, we will include the scientific opinions to it for creating the first draft of our new label. In phase 2, a total of 500 mothers of students 6-12 years old randomly assigned to five groups. The study groups will be as follows: (1) without nutrition label group, (2) current traffic light label group, (3) current traffic light label group in which, a brochure will be used to inform mothers, (4) physical activity calorie equivalent label group, and (5) physical activity calorie equivalent label group in which a brochure will be used to inform mothers. Some samples of dairy products, beverages, cakes, and biscuits will be presented. ANOVA and multiple linear regressions will be used to examine the association between the label type and the main consequence (energy of the selected products) and secondary outcome (time).

DISCUSSION

The effect of the new food labels will be evaluated based on the differences between the calories of selected food groups.

TRIAL REGISTERATION

Iranian Registery of Clinical Trials [IRCT]20,181,002,041,201 N1.

Effects of physical activity calorie equivalent food labelling to reduce food selection and consumption: systematic review and meta-analysis of randomised controlled studies

Background

There is limited evidence that nutritional labelling on food/drinks is changing eating behaviours. Physical activity calorie equivalent (PACE) food labelling aims to provide the public with information about the amount of physical activity required to expend the number of kilocalories in food/drinks (eg, calories in this pizza requires 45 min of running to burn), to encourage healthier food choices and reduce disease.

Objective

We aimed to systematically search for randomised controlled trials and experimental studies of the effects of PACE food labelling on the selection, purchase or consumption of food/drinks.

Methods

PACE food labelling was compared with any other type of food labelling or no labelling (comparator). Reports were identified by searching electronic databases, websites and social media platforms. Inverse variance meta-analysis was used to summarise evidence. Weighted mean differences (WMD) and 95% CIs were used to describe between-group differences using a random effects model.

Results

15 studies were eligible for inclusion. When PACE labelling was displayed on food/drinks and menus, significantly fewer calories were selected, relative to comparator labelling (WMD=−64.9 kcal, 95% CI −103.2 to −26.6, p=0.009, n=4606). Presenting participants with PACE food labelling results in the consumption of significantly fewer calories (WMD=−80.4 kcal, 95% CI−136.7 to −24.2, p=0.005, n=486) relative to comparator food labelling.

Conclusion

Based on current evidence PACE food labelling may reduce the number of kilocalories selected from menus and decrease the number of kilocalories/grams of food consumed by the public, compared with other types of food labelling/no labelling.

Trial registration number

CRD42018088567.

Consumer beliefs about healthy foods and diets

Background

The U.S. Food and Drug Administration has begun a public process to redefine how companies are allowed to use the term “healthy” on food packages. Although the definition is formulated based on the latest consensus in nutrition and epidemiological research, it is also important to understand how consumers define and understand the term if it is to be behaviorally relevant. This research is an exploratory study designed to provide a descriptive account of consumers’ perceptions of and beliefs about the meaning of “healthy” food.

Methods

A nationwide U.S. sample of 1,290 food consumers was surveyed in December 2018. Respondents answered 15 questions designed to gauge perceptions of healthy food and to elicit preference for policies surrounding healthy food definitions. Responses are weighted to demographically match the population. Categorical variables have a sampling error of ±2.7%. Exploratory factor analysis is used to determine latent dimensions of health perceptions related to food type.

Results

Consumers were about evenly split on whether a food can be deemed healthy based solely on the foods’ nutritional content (52.1% believing as such) or whether there were other factors that affect whether a food is healthy (47.9% believing as such). Consumers were also about evenly split on whether an individual food can be considered healthy (believed by 47.9%) or whether this healthiness is instead a characteristic of one’s overall diet (believed by 52.1%). Ratings of individual food products revealed that “healthy” perceptions are comprised of at least three underlying latent dimensions related to animal origin, preservation, and freshness/processing. Focusing on individual macronutrients, perceived healthiness was generally decreasing in a food’s fat, sodium, and carbohydrate content and increasing in protein content. About 40% of consumers thought a healthy label implied they should increase consumption of the type of food bearing the label and about 15% thought the label meant they could eat all they wanted.

Conclusions

Results suggest consumer’s perceptions of “healthy,” which is primarily based on fat content, partially aligns with the FDA definition but also suggest consumers perceive the word as a broader and more nuanced concept that defies easy, uniform definition. Results highlight areas where nutrition education may be needed and suggest disclosures may need to accompany health claims so that consumers know what, precisely, is being communicated.

An Umbrella Review of Systematic Reviews on Food Choice and Nutrition Published between 2017 and-2019

The objective of this umbrella review was to provide an update on the latest knowledge in the field of food choice and nutrition. Databases Scopus and ISI-Web of Science were searched for "food choice" AND nutrition. Papers were included if they were systematic reviews published between January 2017 and August 2019 on any subpopulation group. In total, 26 systematic reviews were kept. Data were extracted with a predetermined grid including first author, publication year, country, population group, explanatory constructs (intervention focus) and reported outcomes. Common indicators for outcome measures on food choice and nutrition studies are nutrition knowledge, healthy food choices, food purchases and food and nutrient intake. The most common strategy implemented to alter food choice with a nutritional aim is nutrition education, followed by provision of information through labels. Among children, parent modelling is key to achieving healthy food choices. In general, combining strategies seems to be the most effective way to achieve healthier food consumption and to maintain good nutrition in all age groups.