Does providing nutrition information at vending machines reduce calories per item sold?

University Food Environment Assessment Methods and Their Implications: Protocol for a Systematic Review

BACKGROUND

While the retail food environment has been well studied, research surrounding the university food environment is still emerging. Existing research suggests that university food environments can influence behavioral outcomes such as students' dietary choices, which may be maintained long-term. Despite a growing interest in assessing university food environments, there is no standardized tool for completing this task. How researchers define "healthy" when assessing university food environments needs to be clarified. This paper describes the protocol for systematically reviewing literature involving university food environment assessments.

OBJECTIVE

This paper aimed to describe the protocol for a systematic review of the assessments of university food environments. The review will summarize previously used tools or methods and their implications.

METHODS

Electronic databases, including PubMed (NLM), Cochrane Library (Wiley), Web of Science (Clarivate), APA PsycINFO (EBSCO), CINAHL (Cumulative Index to Nursing & Allied Health) Complete (EBSCO), ProQuest Nursing and Allied Health, and Google Scholar were searched for papers published between 2012 and 2022 using combinations of related medical subject headings terms and keywords. The electronic databases were supplemented by reviewing the reference list for all included papers and systematic reviews returned with our search results. The review will include all study types, including randomized controlled trials, observational studies, and other pre-post designs. Papers that examine at least 1 aspect of the university food environment, such as cafeterias, campus convenience stores, and vending machines, were considered for inclusion. A total of 2 reviewers will independently screen titles and abstracts, complete a full-text review, extract data, and perform a quality assessment of included papers, with a third reviewer resolving any conflicts. The Quality Assessment for Diverse Studies (QuADS) tool was used to determine the methodological quality of selected studies. A narrative and tabular summary of the findings were presented. There will not be a meta-analysis due to the methodological heterogeneity of the included papers.

RESULTS

The initial queries of 4502 records have been executed, and papers have been screened for inclusion. Data extractions were completed in December 2023. The results of the review were accepted for publication in May 2024. The systematic review generated from this protocol will offer evidence for using different assessment tools to examine the campus food environment.

CONCLUSIONS

This systematic review will summarize the tools and methods used to assess university food environments where many emerging adults spend a significant part of their young adult lives. The findings will highlight variations in practice and how "healthy" has been defined globally. This review will provide an understanding of this unique organizational food environment with implications for practice and policy.

TRIAL REGISTRATION

PROSPERO CRD42023398073; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=398073.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54955.

Improving student diet and food security in higher education using participatory and co-creation approaches: a systematic review

BACKGROUND

Higher education students are an important target group for public health nutrition interventions. When designing tailored and contextually relevant interventions, participatory and co-creation approaches are increasingly recognized as promising but their use and effectiveness has not been assessed in this type of population. We systematically reviewed interventions aiming to improve dietary quality and/or food security in higher education settings with the aims 1) to identify and describe their participatory and co-creation approaches and 2) to compare the effectiveness of interventions using or not using participatory and co-creation approaches.

METHODS

Our search in PubMed, Google Scholar, Web of Science, EMBASE was performed in January 2023 and yielded 3658 unique records, out of which 42 articles (66 interventions) were included. Effectiveness of interventions was assessed at the individual level (longitudinal evaluations) or at the group level (repeated cross-sectional evaluations). A five-level classification was used to describe a continuum of engagement from students and other partners in the intervention design and implementation: no participation (level one), consultation, co-production, co-design and co-creation (levels two to five). To synthetize effectiveness, comparisons were made between studies without participation (level one) or with participation (levels two-five).

RESULTS

Ten (24%) out of 42 studies used a participatory and co-creation approach (levels two-five). Studies using a participatory and co-creation approach reported a positive finding on individual-level outcome (i.e. overall diet quality or food group intake or food security) in 5/13 (38%) intervention arms (vs 13/31 or 42% for those without participation). Studies using a participatory and co-creation approach reported a positive finding on group-level outcomes (i.e. food choices in campus food outlets) in 4/7 (57%) (vs 8/23 or 35% in those without participation).

CONCLUSIONS

Participatory and co-creation approaches may improve the effectiveness of nutrition interventions in higher education settings but the level of evidence remains very limited. More research is warranted to identify best co-creation practices when designing, implementing and evaluating nutritional interventions in the higher education setting.

TRIAL REGISTRATION

PROSPERO registration number CRD42023393004.

Assessing the Healthfulness of University Food Environments: A Systematic Review of Methods and Tools

The availability, promotion, and price of healthy foods within the university food environment may impact students' dietary choices. This systematic review summarizes the tools and methods used to assess the healthfulness of university food environments where many students spend a significant portion of their emerging adulthood. Thirty-six global studies published between 2012 and 2022 were sourced from PubMed (NNLM), Cochrane Library (Wiley), Web of Science (Clarivate), APA PsycInfo (EBSCO), CINHAL Complete (EBSCO), ProQuest Nursing, and Allied Health, following PRISMA 2020 guidelines. Of the included studies, 58% were institutional-level audits, 17% examined individual-level perceptions, and 25% combined both. Most institutional-level audits focused on one aspect of the food environment (e.g., eateries, vending machines). For studies examining multiple spaces within the campus environment (38%), comprehensive assessments were limited, and most studies had to employ a combination of assessment tools. Surveys were most often used to gather individual perceptions about the food environment. The Nutrition Environment Measures Survey (NEMS) was the most commonly used tool across all studies. This review highlights the need for a standardized tool, method, or a "healthy" benchmark for specific use at universities to improve methodological rigor and comparability of findings across institutions.

Comparison of Sales From Vending Machines With 4 Different Food and Beverage Messages: A Randomized Trial

Importance

Point-of-sale food messaging can encourage healthier purchases, but no studies have directly compared multiple interventions in the field.

Objective

To examine which of 4 food and beverage messages would increase healthier vending machine purchases.

Design, Setting, and Participants

This randomized trial assessed 13 months (February 1, 2019, to February 29, 2020) of vending sales data from 267 machines and 1065 customer purchase assessments from vending machines on government property in Philadelphia, Pennsylvania. Data analysis was performed from March 5, 2020, to November 8, 2022.

Interventions

Study interventions were 4 food and beverage messaging systems: (1) beverage tax posters encouraging healthy choices because of the Philadelphia tax on sweetened drinks; (2) green labels for healthy products; (3) traffic light labels: green (healthy), yellow (moderately healthy), or red (unhealthy); or (4) physical activity equivalent labels (minutes of activity to metabolize product calories).

Main Outcomes and Measures

Sales data were analyzed separately for beverages and snacks. The main outcomes analyzed at the transaction level were calories sold and the health status (using traffic light criteria) of each item sold. Additional outcomes were analyzed at the monthly machine level: total units sold, calories sold, and units of each health status sold. The customer purchase assessment outcome was calories purchased per vending trip.

Results

Monthly sales data came from 150 beverage and 117 snack vending machines, whereas 1065 customers (558 [52%] male) contributed purchase assessment data. Traffic light labels led to a 30% decrease in the mean monthly number of unhealthy beverages sold (mean ratio [MR], 0.70; 95% CI, 0.55-0.88) compared with beverage tax posters. Physical activity labels led to a 34% (MR, 0.66; 95% CI, 0.51-0.87) reduction in the number of unhealthy beverages sold at the machine level and 35% (MR, 0.65; 95% CI, 0.50-0.86) reduction in mean calories sold. Traffic light labels also led to a 30-calorie reduction (b = -30.46; 95% CI, -49.36 to -11.56) per customer trip in the customer purchase analyses compared to physical activity labels. There were very few significant differences for snack machines.

Conclusions and Relevance

In this 13-month randomized trial of 267 vending machines, the traffic light and physical activity labels encouraged healthier beverage purchases, but no change in snack sales, compared with a beverage tax poster. Corporations and governments should consider such labeling approaches to promote healthier beverage choices.

Trial Registration

ClinicalTrials.gov Identifier: NCT06260176.

Effect of using the snackability app on snack quality among US college students with overweight and obesity: A randomized controlled trial

OBJECTIVE

To determine if using the Snackability app improves snack intake among college students.

PARTICIPANTS

US college students with overweight/obesity were recruited in June 2020-April 2021.

METHODS

A randomized controlled trial was conducted to test the Snackability app use for 12 wk on snack scores (calculated from the app) compared to controls. We also explored the effect on diet quality (Healthy Eating Index-2015) and weight. Outcomes were compared between the intervention and the control groups at 4, 8, and 12 wk using repeated measures ANOVA.

RESULTS

Participants in the app group significantly increased snack score at week 4 (p < 0.001) and week 8 (p = 0.015) and increased HEI-2020 score (p < 0.001) at week 4 compared to controls. The first 4 wk had the highest app usage. No significant differences were seen in body weight.

CONCLUSIONS

The Snackability app can be used as a tool to help improve snack and diet quality in this group.

Perception about the effectiveness of different vending machine interventions to promote healthier snack selection among college students

OBJECTIVE

Evaluate college students' perception of the effectiveness of different vending machine (VM) interventions for improving snack selection.

PARTICIPANTS

A total of 194 college students with the age of ≥18 years.

METHOD

A cross-sectional survey among a purposive sampling near VM.

RESULTS

Most students use VM frequently or occasionally (63.4%). The intervention perceived as most helpful for choosing healthier snacks was labeling (on or near) which snack is healthy (score 3.83/5) followed by lowering the price of healthy options (score 3.33/5), while the least helpful was having posters nearby explaining which snacks are healthier (2.35/5). Participants suggested including snacks high in protein (58.8%) and low in sugar (56.2%). Most would like to see more healthy options in VM (83.5%) and will purchase them if available (67%).

CONCLUSIONS

Lowering the price for healthy snacks and including labels to indicate which are healthy may be the interventions to test for improving snack intake among college students.

Impact of Smart Snacks Intervention on College Students' Vending Selections

OBJECTIVES

To place Smart Snacks in vending machines and determine if different sales strategies affect Smart Snack selection.

PARTICIPANTS

University students living in resident halls.

METHODS

Vending machines included 50% Smart Snacks and 50% non compliant snacks. Three sales strategies targeted student selection of Smart Snacks: Reduced price, signage, and nutrition education activities. Three-way ANOVA was used for analysis.

RESULTS

There was a statistically significant three-way interaction on snack selection between sales strategy, study period, and snack type, F(4, 77) = 3.33, P = .01. There were no statistically significant simple two-way interaction between study period and sales strategy for either Smart Snack, F(1, 77) = 1.62, P = 0.18, or NC snack types, F(1, 77) = 2.02, P = 0.07.

CONCLUSIONS

Sales strategies did not affect Smart Snack selections. Advocates for healthier snacks in vending machines can align with university administrations to establish nutrient guidelines.

Factors That "Nudge People towards the Healthier" Snacks-A Qualitative Study with Student, Faculty, and Staff Leaders and Decision Makers

(1) College campuses pose numerous public health challenges for students, faculty and staff. The healthfulness of the snacks available on campuses is lacking, and there is a desire for change among the students and staff. The objective of this study is to understand the perspectives of the students, staff, and decision makers regarding the college campus food environment and the perceived facilitators and barriers to improving it. (2) In-depth interviews were conducted (n = 15) with decision makers in food, policy development, wellness, and nutrition at a large Hispanic-Serving University in South Florida. (3) The key stakeholders shared that educational campaigns, student buy-in, raising awareness around obesity and chronic disease, and the university's position within the community would all help to facilitate improvements to the snack food environment. However, the participants noted that the complex nature of what is considered to be healthy and what divergent consumers want are significant barriers to improving the snack food environment along with concerns over lost revenue and the corporate structure. (4) These results inform potential focal points for multi-level interventions and inform policy discussions focused on improving the snack food environment at minority-serving universities. Taking strategic actions to improve the snack food environment may aid the students and staff of the university to enhance their diet quality.

College Students' Perception of Snacks Sold in Vending Machines in the US: A Mixed-Methods Study

Introduction: Food in vending machines in US colleges contain limited nutritious foods available for purchase, which could affect the food choices made by students leading to poor diet quality. Interventions to improve college foodscapes usually follow a top-down approach and fail to affect dietary behavioral changes ultimately. This research aims to uncover what students want and ways to achieve change.

Methods: The mixed-methods approach included peer-led qualitative focus group discussions and a brief quantitative questionnaire on satisfaction from foods available in vending machines. A convenience sample of 20 students (15 females) was recruited from a Hispanic serving institution for this study.

Results: Vending machines were perceived as convenient, plentiful, and unhealthy. Students expressed dissatisfaction with both the variety and nutritional quality of snacks in vending machines. Suggestions for improvement included more fresh items (fruits and vegetables) and refrigerated items with higher protein content (low-fat yogurt, hummus, and peanut butter). To implement these improvements, participants discussed the cost and feasibility of perishable items. Increasing awareness and partnering strategies were proposed to mediate potential cost and buy-in obstacles as was elevating the appeal of healthy vending machines with technological enhancements that draw customers in and educate.

Conclusion and Implication for Practice: This group of college students was eager for positive changes in foods sold in vending machines and understand the major difficulties. The suggested changes may help this and other colleges develop policies to regulate the foods in vending machines to promote overall health and help prevent chronic diseases in the future.

Toward a Healthy and Environmentally Sustainable Campus Food Environment: A Scoping Review of Postsecondary Food Interventions

Interventions are urgently needed to transform the food system and shift population eating patterns toward those consistent with human health and environmental sustainability. Postsecondary campuses offer a naturalistic setting to trial interventions to improve the health of students and provide insight into interventions that could be scaled up in other settings. However, the current state of the evidence on interventions to support healthy and environmentally sustainable eating within postsecondary settings is not well understood. A scoping review of food- and nutrition-related interventions implemented and evaluated on postsecondary campuses was conducted to determine the extent to which they integrate considerations related to human health and/or environmental sustainability, as well as to synthesize the nature and effectiveness of interventions and to identify knowledge gaps in the literature. MEDLINE (via PubMed), CINAHL, Scopus, and ERIC were searched to identify articles describing naturalistic campus food interventions published in English from January 2015 to December 2019. Data were extracted from 38 peer-reviewed articles, representing 37 unique interventions, and synthesized according to policy domains within the World Cancer Research Foundation's NOURISHING framework. Most interventions were focused on supporting human health, whereas considerations related to environmental sustainability were minimal. Interventions to support human health primarily sought to increase nutrition knowledge or to make complementary shifts in food environments, such as through nutrition labeling at point of purchase. Interventions to support environmental sustainability often focused on reducing food waste and few emphasized consumption patterns with lower environmental impacts. The implementation of integrated approaches considering the complexity and interconnectivity of human and planetary health is needed. Such approaches must go beyond the individual to alter the structural determinants that shape our food system and eating patterns.

Nutritional quality of beverages available in vending machines in health and social care institutions: do we really want such offers?

BACKGROUND

Vending machines represent one way of offering food, but they are overlooked in the efforts to improve people's eating habits. The aim of our study was to analyse the variety and nutritional values of beverages offered in vending machines in social and health care institution in Slovenia.

METHODS

The available beverages were quantitatively assessed using traffic light profiling and the model for nutrient profiling used by Food Standards Australia New Zealand. Vending machines in 188 institutions were surveyed, resulting in 3046 different beverages consisting of 162 unique product labels.

RESULTS

Between 51 and 54% of beverages were categorised as unhealthy with regard to sugar content. Water accounted for only 13.7% of all beverages in vending machines. About 82% of beverages in vending machines were devoted to sugar-sweetened beverages, the majority (58.9%) presented in 500-ml bottles. The average sugar content and average calories in beverages sold in vending machines are slightly lower than in beverages sold in food stores.

CONCLUSIONS

We suggest that regulatory guidelines should be included in the tender conditions for vending machines in health and social care institutions, to ensure healthy food and beverage choices.

College campuses' influence on student weight and related behaviours: A review of observational and intervention research

Research indicates that most college students are not meeting dietary and physical activity guidelines, and the average student gains an estimated 1.6-3.0 kg during 4 years of study. College administrations are well-positioned to influence student weight-related health behaviours by ensuring that campus environments/policies promote health. However, to date, campus health interventions have largely addressed individual and interpersonal factors rather than environmental/policy-level changes. Using an ecological perspective, this narrative review synthesizes the literature on campus environmental/policy-level factors (e.g., food availability, physical activity requirements) associated with student diet, physical activity and weight, as well as campus interventions to address these factors. Web of Science and PubMed databases were searched between December 2018 and November 2019. Results indicate that campus food environments may contribute to overconsumption and weight gain, and the number of campuses requiring students to participate in physical activity courses is in decline. Eight examples of environmental/policy-level campus interventions are presented: nutrition labels in dining halls, campus-wide healthy choice marketing campaigns, restricted payment methods for à la cart dining, trayless dining, health-themed residence halls, peer health education programmes, active classroom spaces and physical activity course requirements. Implications for research and health promotion programmes/policies in the field of college health are discussed.

Effectiveness of Nutrition Interventions in Vending Machines to Encourage the Purchase and Consumption of Healthier Food and Drinks in the University Setting: A Systematic Review

University food environments typically offer an abundance of unhealthy foods, including through vending machines. This review evaluated the effectiveness of nutrition interventions in vending machines in the university setting. Ten databases were searched for experimental studies published up to July 2019, evaluating nutrition interventions that aimed to encourage the purchase or consumption of healthier foods and drinks in vending machines in the university setting. In total, 401 articles were identified, and 13 studies were included. Studies were pre-post test (n = 7, 54%), randomized controlled trials (RCTs) (n = 5, 38%), and non-randomized controlled trial (n = 1, 8%). Most studies were from the USA (n = 10, 77%) and were published between 2014 and 2018 (n = 9, 69%). Eight interventions (62%) reported positive change in outcomes, including increased number/proportion of sales or revenue from healthier items (n = 6), improved adherence to guidelines for the ratio of healthy/unhealthy products available (n = 1), and improved consumer perception of items available (n = 1). Effective interventions involved the promotion, reduced pricing, increased availability, and/or optimized product placement of healthier items within vending machines. Strategies to improve the nutritional quality of food and drinks in vending machines are warranted. This may be achieved by making healthier options more available and promoting them; however, more robust intervention studies are needed to determine effectiveness.

Evaluating the Potential Health and Revenue Outcomes of a 100% Healthy Vending Machine Nutrition Policy at a Large Agency in Los Angeles County, 2013-2015

CONTEXT

Healthy vending machine policies are viewed as a promising strategy for combating the growing obesity epidemic in the United States. Few studies have evaluated the short- and intermediate-term outcomes of healthy vending policies, especially for interventions that require 100% healthy products to be stocked.

OBJECTIVE

To evaluate the potential impact of a 100% healthy vending machine nutrition policy.

DESIGN

The vendor's quarterly revenue, product sales records, and nutritional information data from 359 unique vending machines were used to conduct a baseline and follow-up policy analysis.

SETTING

County of Los Angeles facilities, 2013-2015.

PARTICIPANTS

Vending machines in facilities located across Los Angeles County.

INTERVENTION

A healthy vending machine policy executed in 2013 that required 100% of all products sold in contracted machines meet specified nutrition standards.

OUTCOME MEASURES

Policy adherence; average number of calories, sugar, and sodium in food products sold; revenue change.

RESULTS

Policy adherence increased for snacks and beverages sold by the vending machines by 89% and 98%, respectively. Average snack and beverage revenues decreased by 37% and 34%, respectively, during the sampled period.

CONCLUSIONS

Although a 100% healthy vending policy represents a promising strategy for encouraging purchases of healthier foods, steps should be taken to counteract potential revenue changes when planning its implementation.

Food Choices of Young Adults in the United States of America: A Scoping Review

Understanding food choice is critical to developing effective health promotion efforts to counter the leading causes of morbidity and mortality in the United States. Although physiologic, environmental, and social factors influence the development of health conditions, routine decisions, such as food choice, also contribute substantially over time. Behavioral scientists believe that these routine decisions represent a key opportunity to improve population health. We conducted a scoping review of both health and business literature to identify themes in the food choices of young adults aged 19-24 y in the United States. Informed by the Joanna Briggs Institute processes for scoping reviews, we conducted a structured search of 8 health and business databases on 18 April 2017. The databases were PubMed, Business Source Complete, PsycInfo, Cochrane Library, CINAHL, Web of Science, SCOPUS, and ABI/Inform Collection. Eligible literature captured real-world dietary choices of the general population of young adults between 1 January, 2007 and 31 December, 2017. Records were screened in Covidence. Data was extracted into Excel and key findings thematically analyzed. The search returned 9085 records. Ninety-nine records met the eligibility criteria. Themes identified in the foods chosen by young adults include inadequate fruit and vegetable consumption, choosing international flavors and food formats, convenience foods, frequent snacking, the selection of healthy foods based on perceptions of what is healthy rather than the nutrient or calorie content of foods, an interest in sustainable production methods, the desire to customize/tailor foods, foods young people find interesting, and regional foods. This research identified common food choices that can help inform the tailoring of health promotion efforts; however, more research is needed to understand the underlying mechanisms and principles shaping these choices.

Power Estimation in Planning Randomized Two-Arm Pre-Post Intervention Trials with Repeated Longitudinal Outcomes

Background:

Intervention effect on ongoing medical processes is estimated from clinical trials on units (i.e. persons or facilities) with fixed timing of repeated longitudinal measurements. All units start out untreated. A randomly chosen subset is switched to the intervention at the same time point. The pre-post switch change in the outcome between these units and unswitched controls is compared using Generalized Least Squares models. Power estimation for such studies is hindered by lack of available GLS based approaches and normative data.

Methods:

We derive Generalized Least Squares variance of the intervention effect. For the commonly assumed compound symmetry correlation structure, this leads to simple power formulas with important optimality properties. To maximize power given a constrained number of total time points, we investigate on the optimal pre-post allocation with the local minimization of variance.

Results:

In four examples from nursing home and HIV patients, the Toepltiz within-unit correlation of repeated measures differed from compound symmetry. We applied empirical Toeplitz based calculations for variance of the estimated intervention effect to these examples (each with up to seven longitudinal measures). Unlike what happened under compound symmetry, where power was often maximized with multiple observations being pre-intervention, for these examples, having one pre-intervention measure tended to maximize power. Attempts to approximate the Toeplitz variance structures with compound symmetry (to take advantage of the simpler formulas) resulted in overestimation of power for these examples.

Conclusions:

While compound symmetry correlation among repeated within-unit measures leads to simple power estimation formulas, this structure often did not hold. There may be strong underestimation of variance of the intervention effect estimate from incorporating short-term within-unit correlation estimates as a common compound symmetry correlation to approximate an unknown Toeplitz correlation without adequately accounting for the correlation between repeated measures declining with time.

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.

Vending Machines: A Narrative Review of Factors Influencing Items Purchased

Vending machines are a ubiquitous part of our food environments. Unfortunately, items found in vending machines tend to be processed foods and beverages high in salt, sugar, and/or fat. The purpose of this review is to describe intervention and case studies designed to promote healthier vending purchases by consumers and identify which manipulations are most effective. All studies analyzed were intervention or case studies that manipulated vending machines and analyzed sales or revenue data. This literature review is limited to studies conducted in the United States within the past 2 decades (ie, 1994 to 2015), regardless of study population or setting. Ten articles met these criteria based on a search conducted using PubMed. Study manipulations included price changes, increase in healthier items, changes to the advertisements wrapped around vending machines, and promotional signs such as a stoplight system to indicate healthfulness of items and to remind consumers to make healthy choices. Overall, seven studies had manipulations that resulted in statistically significant positive changes in purchasing behavior. Two studies used manipulations that did not influence consumer behavior, and one study was equivocal. Although there was no intervention pattern that ensured changes in purchasing, price reductions were most effective overall. Revenue from vending sales did not change substantially regardless of intervention, which will be important to foster initiation and sustainability of healthier vending. Future research should identify price changes that would balance healthier choices and revenue as well as better marketing to promote purchase of healthier items.

A systematic literature review of nutrition interventions in vending machines that encourage consumers to make healthier choices

Internationally, vending machines are scrutinized for selling energy-dense nutrient-poor foods and beverages, and the contribution to overconsumption and subsequent risk of obesity. The aim of this review is to determine the efficacy of nutrition interventions in vending machine in eliciting behaviour change to improve diet quality or weight status of consumers. Electronic databases Cochrane, EMBASE, CINAHL, Science Direct and PubMed were searched from inception.

INCLUSION CRITERIA

(i) populations that have access to vending machines; (ii) nutrition interventions; (iii) measured outcomes of behaviour change (e.g. sales data, dietary intake or weight change); and (iv) experimental trials where controls were not exposed to the intervention. Risk of bias was assessed independently by two researchers, and higher quality research formed the basis of this qualitative review. Twelve articles from 136 searched were included for synthesis. Intervention settings included schools, universities and workplaces. Reducing price or increasing the availability increased sales of healthier choices. The results of point-of-purchase nutrition information interventions were heterogeneous and when measured changes to purchases were small. This review offers evidence that pricing and availability strategies are effective at improving the nutritional quality foods and beverages purchased from vending machines. Evidence on how these interventions alter consumer's overall diet or body mass index is needed.