Vending machine assessment methodology. A systematic review

Addressing nutritional issues and eating behaviours among university students: a narrative review

University life is a critical period for establishing healthy eating habits and attitudes. However, university students are at risk of developing poor eating habits due to various factors, including economic conditions, academic stress and lack of information about nutritional concepts. Poor diet quality leads to malnutrition or overnutrition, increasing the risk of preventable diseases. Food environments on university campuses also play a significant role in shaping the dietary habits of students, with the availability of and accessibility to healthy food options being important factors influencing food choices and overall diet quality. Disordered eating habits and body dissatisfaction are prevalent among university students and can lead to eating disorders. Income and living arrangements also influence dietary habits, with low household income and living alone being associated with unhealthy eating habits. This study is a narrative review that aimed to address nutritional issues and eating behaviours, specifically among university students. We investigated the eating behaviours of university students, including their dietary patterns, food choices and food environments. The objective of this review was to provide insights into the nutritional issues and eating behaviours of university students, with the aim of identifying target areas for intervention to improve the overall health and wellbeing among college students. University food environments need to be restructured to promote healthy eating, including the availability, accessibility, affordability and labelling of healthy foods, and policies to limit the availability of unhealthy foods and drinks on campus.

Evaluation of an experiment to increase availability of healthier snack foods in vending machines situated within English sports facilities

OBJECTIVE

To evaluate the impact of increased availability of healthier options on purchasing of different types of vending snack products sold in English leisure (sports) centres.

DESIGN

An evaluation of an intervention using pre-post methods and interrupted time series analysis. Products within the vending machines were altered over three phases to increase the availability of healthier options, using agreed nutrition criteria - Government Buying Standards for Food and Catering Services (GBSF) for England - as a guide, as well as product availability. The primary outcome was the change in mean weekly purchased energy between the first and third phase. Secondary outcomes included changes by phase and by week in weekly number of purchases, fats, sugars and salt for all products combined and by individual product categories.

SETTING

Fifteen sports centres in the city of Leeds, West Yorkshire, UK.

PARTICIPANTS

Snack products sold in eighteen vending machines.

RESULTS

Energy purchased reduced from baseline to phase 2, for all product categories combined, by 47·25 MJ (95 % CI (-61·22, -33·27)) per machine and by 279 kJ, (95 % CI (-325, -266)) per product unit. There were reductions in most nutrients purchased in all individual product categories except chocolate confectionery. Nutrients per product unit decreased for all product categories except saturated fat in chocolate confectionery. Minimal underlying trends in the baseline phase were identified, indicating changes in outcomes were likely to be due to the intervention.

CONCLUSIONS

Introducing standards to increase availability of healthier snack products in vending machines is feasible without substantially affecting sales.

Consumption of ultra-processed food and its association with obesity in Chilean university students: A multi-center study

OBJECTIVE

To explore the associations between the consumption of three categories of ultra-processed food (sugary beverages, sweet, and salty snacks) and body mass index (BMI) among Chilean university students.

METHODS

We conducted a multi-center, descriptive study among 2,039 students from 6 Chilean universities. Food consumption was surveyed using a validate food survey. That height and body weight were objectively measured to calculate BMI for determining weight status, and also, tobacco use and physical activity were measured.

RESULTS

An intake equal to or higher than 1 serving of sugary beverage a day was associated with greater odds of obesity in university students (OR:1.32 [95% CI: 1.00, 1.74]), 2 servings/day (OR: 1.30 [95% CI: 1.04, 1.50]), and 3 servings/day (OR: 1.39 [95% CI: 1.05, 1.80]). Neither consumption of sweet nor salty snacks (≥1 servings/day) related to differential odds of obesity: (OR: 0.83 [95% CI: 0.42, 1.64]) and (OR: 1.79 [95% CI: 0.93, 3.41]), respectively.

CONCLUSION

In a sample of Chilean university students, consumption of sugary beverages, and not consumption of sweet or salty snacks, was associated with obesity.

Study on Energy Efficiency of an Off-Grid Vending Machine with Compact Heat Exchangers and Low GWP Refrigerant Powered by Solar Energy

The purpose of this research is to design an energy-efficient off-grid vending machine that has a refrigeration system powered by an environmentally friendly refrigerant. The paper presents details from the equipment’s design phase in terms of the resistance structure, photovoltaic panels area dimensioning, but also in terms of the necessary cooling load to be provided by the refrigeration system. The refrigerant chosen was R290 following a comparative analysis, which showed that it has an efficiency 6.6% higher than R134a. During the monitoring periods, the outdoors temperature varied between −4–28 °C, the relative humidity between 22–100% and yet only a slight indoor temperature variation of ±1.5 °C compared to the set value was recorded. The battery module managed to store enough energy from the photovoltaic panels to keep the vending machine functional through three consecutive days with adverse environmental conditions, as evidenced by the low variation of indoor temperature

Consumption, Attitudes, and Trends of Vending Machine Foods at a University Campus: A Cross-Sectional Study

Vending machines (VMs) have been identified as an obesogenic factor, offering mainly energy-dense and nutrient-poor foods, with limited healthy options available. This cross-sectional study aimed to assess consumption trends and attitude toward vending machine (VM) foods in a university setting. A web-based survey was conducted among 1250 students and staff. Most participants reported weight gain (43.4%) and poorer food choices (53.4%) since joining the university. Participants described VM foods as expensive (53.7%) and lacking variety (34.3%). Over 81% demanded the availability of healthier options. About 75% of participants were VMs users. The most frequently purchased VM items were water, chocolate, and chips. Males reported consuming nuts, soda, iced tea, and energy drinks more frequently than females (p < 0.005). The main reasons for using the VM were hunger and lack of time. Over 40% nominated fresh fruits, baked chips, sandwiches, and dry roasted nuts to be provided in the VMs as healthier food options. Males and those responsible for buying their own food were more likely to select healthier options (p = 0.001). Findings can be used to inform stakeholders of current vending behaviors and to plan tailored interventions to improve the nutritional quality of vended items and promote healthier food choices.

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.

Availability, Nutritional Profile and Processing Level of Food Products Sold in Vending Machines in a Spanish Public University

BACKGROUND

Given the lack of data about the nutritional value and other determinants of the consumption of foods and drinks sold in vending machines in European universities and the relevance of this sector in Spain, it is necessary to obtain scientific data on this topic. The present study aimed to assess the availability, nutritional profile and processing level of food products from vending machines at a Spanish public university and to investigate differences in nutritional profile according to the cost and promotion.

METHODS

Cross-sectional descriptive study. Data from all products available (3894) were collected and analysed using the criteria of the Spanish Agency for Consumption, Food Safety and Nutrition and the United Kingdom nutrient profiling model. The items were also classified according to the degree of industrial processing through the NOVA system. Promotion was assessed, taking into account where products were displayed in vending machines.

RESULTS

The most common products were sweets (23.4% of the total options), coffee (20.3%) and salty snacks (11.7%). According to the combination of the two criteria used to assess nutritional profile, 48.6% of the products were classified as with low nutritional quality (LNQ). In addition, 73.8% of the items were categorised as "ultra-processed". Foods (β = 0.31, 95% CI 0.24, 0.39, p < 0.001) and hot drinks (β = 0.46, 95% CI 0.39, 0.52, p < 0.001) with high nutritional quality (HNQ) were more likely to have higher prices than alternatives with LNQ. Both foods and cold drinks that support healthy dietary recommendations were promoted to a lesser extent than those with LNQ (p < 0.001).

CONCLUSION

Almost half of the products were of LNQ and three-quarters had a high level of processing. Moreover, foods and cold drinks with LNQ were less expensive and more often promoted than alternatives with HNQ.

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.

[Nutritional composition of vending foods of public university and hospital buildings in Asturias]

OBJECTIVE

To evaluate the nutritional composition of food vending machines (VM) located in university public buildings and hospitals in Asturias.

DESIGN

Descriptive cross-sectional study.

LOCATION

The analysis was made of the contents of VMs located in public buildings, hospitals, and university teaching centres in the Principality of Asturias.

MAIN MEASUREMENTS

After the public buildings were mapped, each of them was visited to check for the presence of the VMs. A a photograph was then taken of the food contained in them. The variables analysed were the type of products and their nutritional composition.

RESULTS

The VMs of 19 buildings (12 university and 7 hospital), contained 215 foods that were grouped into 11 categories. The most frequent were "chocolates and chocolate bars" (30,2%), "cookies" (11.6%) and "chips" (11.6%). The Kcal average was 216 (SD=133.1). The mean fat, in grams was 12.52 (SD=11.21), saturated fat 4.48 (SD=3,83), sugars 11.88 (SD=31.13), fibre 1.9 (SD=2.47), proteins 3.38 (SD=3.62), and salt 0.3 (SD=0.62). A high excess of fat, saturated fat, and salt was observed, as well as a medium excess of sugars.

CONCLUSIONS

The nutritional quality of VM in hospitals and public university centres of the Principality of Asturias cannot be defined as healthy. Therefore, health promotion strategies could be developed with the aim of improving their nutritional composition or guiding the population/users towards the selection and consumption of healthier foods.

Exploring Nutrition Labelling of Food and Beverages in Vending Machines in Canadian Recreational Sport Settings

Purpose: To evaluate whether interpretive "health" labels placed in vending machines in recreation centres represented products' nutrient content when compared with provincial nutrition guidelines. Methods: A cross-sectional audit (November 2015 - April 2016) of 139 vending machines in recreation facilities found 525 foods and beverages in 17 machines labelled by vendors according to healthfulness. Product nutrient content was compared with provincial nutrition guideline criteria. Cross-tabulation and weighted Cohen's kappa evaluated agreement between vendor interpretive labels and guideline ranks. Descriptive statistics evaluated how mislabelled products deviated from recommended nutrient content. Mann-Whitney tests compared nutrient content of "healthy" and "unhealthy" labelled products. Results: Almost one-third of all products were mislabelled by vendors with 72% of those labelled healthier than their actual guideline rank. Energy, total fat, sugar, and sodium contents exceeded recommended levels in one-third to one-half of mislabelled products. Overall, products labelled healthy by vendors were significantly lower in energy, sodium, and fat compared with those labelled unhealthy; however, not for all food types (e.g., bars, fruit snacks, nuts). Conclusions: For certain product categories, vendor interpretive nutrition labels poorly represented products' nutrient content according to provincial nutrition guidelines. Dietitians may be a valuable resource to help implement nutrition guidelines to create credible interpretive product labelling systems.

Development and Validation of the Vending Evaluation for Nutrient-Density (VEND)ing Audit

Background: This paper describes the development and validation of the Vending Evaluation for Nutrient-Density (VEND)ing audit to comprehensively evaluate vended products based upon healthfulness, price and promotion, and machine accessibility. Methods: A novel vending nutrient-density score was created to determine the healthfulness of vended snack/beverage products. Field tested in United States colleges, VENDing audit (∑nutrient-density + 10 × % healthy products) and Support sub-scores (price + promotion + accessibility) were calculated for snack/beverage machines. Higher scores indicate more healthful vending options and supports for choosing healthfully. Nutrition Environment Measures Survey-Vending (NEMS-V) was used to validate the nutrient-density score for a sub-sample of machines. Sensitivity and specificity were computed by comparing the number of healthy snacks/beverages determined by NEMS-V and the VENDing nutrient-density scores. Results: Researchers conducted the VENDing audit on 228 snack/beverage vending machines at 9 universities within the United States and used both VENDing and NEMS-V on 33 snack and 52 beverage vending machines. Mean VENDing audit scores were 4.5 ± 2.0 (2.6, 3.4) and 2.6 ± 2.0 (0, 12) for snack/beverage machines, respectively. The number of products considered healthy assessed with both the VENDing nutrient-density scores and the NEMS-V were positively correlated for beverages (r = 0.687, p < 0.001) and snacks (r = 0.366, p < 0.05). The sensitivity was excellent for beverages (0.83) and moderate for snacks (0.69); while the specificity was moderate for both beverages (0.66) and snacks (0.50). Conclusions: The VENDing audit uses unique, valid, and reliable nutrient-density scoring to evaluate snacks/beverages along a continuum of healthful criteria and comprehensively evaluates the full vending environment.

Changes in the nutritional quality of products sold in university vending machines since implementation of the health star rating in 2014; an environmental audit

Background

Snacking is a prevalent dietary behaviour among young adults, which could independently contribute to weight gain. Vending machines provide easy access to unhealthy snacks and beverages for young adults in universities. A voluntary front-of-pack labelling, named the Health Star Rating (HSR) system, has been implemented nationally by the Australian government as one strategy to address obesity since 2014. The primary aim of this study was to detect changes in the availability, pricing and advertising of healthy and unhealthy snacks and beverages in university vending machines after introduction of the HSR.

Methods

The study design was two cross-sectional audits of university vending machines one before (in 2014) and another after (in 2017) the implementation of the HSR. Data collections were conducted in a large urban university (> 60,000 students). Every machine was assessed; the product’s name, price, portion sizes and advertisements were recorded. Products were assigned an HSR to classify as healthy (≥3.5 stars) or unhealthy (< 3.5 stars). To compare the differences of product availability between 2014 and 2017, the Chi-square test was used.

Results

A total of 1836 and 2458 slots were audited in 2014 and 2017, respectively. The proportion of healthy snacks and beverages increased from 7 to 14% (p < 0.001) and 38 to 44% (p < 0.05) since 2014, respectively. The mean costs of unhealthy snacks and healthy beverages increased after three years. Healthy food and drink options were more expensive than unhealthy choices in 2017. Advertisements on vending machines for unhealthy foods and drinks remained prevalent.

Conclusion

Only small changes have been observed in the availability of healthy snacks and beverages in vending machines since implementation of the HSR system. Policy directives are indicated to encourage further improvements.

Development of the 'Canteen Scan': an online tool to monitor implementation of healthy canteen guidelines

Background

To improve the availability and accessibility of healthier food and drinks in schools, sports and worksites canteens, national Guidelines for Healthier Canteens were developed by the Netherlands Nutrition Centre. Until now, no tool was available to monitor implementation of these guidelines. This study developed and assessed the content validity and usability of an online tool (the ‘Canteen Scan’) that provides insight into and directions for improvement of healthier food products in canteens.

Methods

The Canteen Scan was developed using a three-step iterative process. First, preliminary measures and items to evaluate adherence to the guidelines were developed based on literature, and on discussions and pre-tests with end-users and experts from science, policy and practice. Second, content validity of a paper version of the Canteen Scan was assessed among five end-users. Third, the online Canteen Scan was pilot tested among end-users representing school canteens. Usability was measured by comprehensibility, user-friendliness, feasibility, time investment, and satisfaction.

Results

The content validity of the Canteen Scan was ensured by reaching agreement between stakeholders representing science, policy and practice. The scan consists of five elements: 1) basic conditions (e.g. encouragement to drink water and availability of policy regarding the guidelines), 2) product availability offered on displays (counter, shelf) and 3) in vending machines, 4) product accessibility (e.g. promotion and placement of products), and 5) an overall score based on the former elements and tailored feedback for creating a healthier canteen. The scan automatically classifies products into healthier or less healthy products. Pilot tests indicated good usability of the tool, with mean scores of 4.0–4.6 (5-point Likert scale) on the concepts comprehensibility, user-friendliness and feasibility.

Conclusion

The Canteen Scan provides insight into the extent to which canteens meet the Dutch Guidelines for Healthier Canteens. It also provides tailored feedback to support adjustments towards a healthier canteen and with the scan changes over time can be monitored. Pilot tests show this tool to be usable in practice.

Leveraging delay discounting for health: Can time delays influence food choice?

Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02359916.

Beverages and snacks available in vending machines from a subset of Ontario secondary schools: Do offerings align with provincial nutrition standards?

OBJECTIVES

As part of an evaluation of Ontario's School Food and Beverage Policy (P/PM 150) in a populous Ontario region, this research aimed to: 1) identify, describe and categorize beverages and snacks available for purchase in secondary school vending machines according to P/PM 150 standards; and 2) compare the number and percentage of beverages and snacks within P/PM 150 categories (Sell Most, Sell Less, Not Permitted) from Time I (2012/2013) to Time II (2014).

METHODS

Representatives from consenting secondary schools assisted researchers in completing a Food Environmental Scan checklist in Times I and II. Sourced nutritional content information (calories, fats, sodium, sugars, ingredients and % daily values) was used to categorize products. The number and percentage of products in P/PM 150 categories were compared between Times by paired t-tests.

RESULTS

Of 26 secondary schools participating in total, 19 participated in both Time periods and were included in the study. There were 75 beverages identified (59 Time I, 45 Time II), mostly water, juices and milk-based beverages; and 132 types of snacks (87 Time I, 103 Time II), mostly grain-based snacks, vegetable/fruit chips, and baked goods. A majority of schools offered one or more Not Permitted beverages (47% Time I, 58% Time II) or snacks (74% Time I, 53% Time II). Significantly more schools met P/PM 150 standards for snacks (p = 0.02) but not beverages in Time II.

CONCLUSION

Full P/PM 150 compliance was achieved by few schools, indicating that schools, school boards, public health, and food services need to continue to collaborate to ensure nutrient-poor products are not sold to students in school settings.

Are products sold in university vending machines nutritionally poor? A food environment audit

AIM

(i) To audit the nutritional composition, promotion and cost of products available from vending machines available to young adults; and (ii) to examine the relationship between product availability and sales.

METHODS

A cross-sectional analysis of snacks and beverages available and purchased at a large urban university was conducted between March and September 2014. Sales were electronically tracked for nine months.

RESULTS

A total of 61 vending machines were identified; 95% (n = 864) of the available snacks and 49% of beverages (n = 455) were less-healthy items. The mean (SD) nutrient value of snacks sold was: energy 1173 kJ (437.5), saturated fat 5.36 g (3.6), sodium 251 mg (219), fibre 1.56 g (1.29) and energy density 20.16 kJ/g (2.34) per portion vended. There was a strong correlation between the availability of food and beverages and purchases (R² = 0.98, P < 0.001).

CONCLUSIONS

Vending machines market and sell less-healthy food and beverages to university students. Efforts to improve the nutritional quality are indicated and afford an opportunity to improve the diet quality of young adults, a group at risk of obesity.

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.

Description, measurement and evaluation of tertiary-education food environments

Obesity in young adults is an increasing health problem in Australia and many other countries. Evidence-based information is needed to guide interventions that reduce the obesity-promoting elements in tertiary-education environments. In a food environmental audit survey, 252 outlets were audited across seven institutions: three universities and four technical and further education institutions campuses. A scoring instrument called the food environment-quality index was developed and used to assess all food outlets on these campuses. Information was collated on the availability, accessibility and promotion of foods and beverages and a composite score (maximum score=148; higher score indicates healthier outlets) was calculated. Each outlet and the overall campus were ranked into tertiles based on their ‘healthiness’. Differences in median scores for each outcome measure were compared between institutions and outlet types using one-way ANOVA with post hoc Scheffe’s testing, χ2 tests, Kruskal–Wallis H test and the Mann–Whitney U test. Binomial logistic regressions were used to compare the proportion of healthy v. unhealthy food categories across different types of outlets. Overall, the most frequently available items were sugar-sweetened beverages (20 % of all food/drink items) followed by chocolates (12 %), high-energy (>600 kJ/serve) foods (10 %), chips (10 %) and confectionery (10 %). Healthy food and beverages were observed to be less available, accessible and promoted than unhealthy options. The median score across all outlets was 72 (interquartile range=7). Tertiary-education food environments are dominated by high-energy, nutrient-poor foods and beverages. Interventions to decrease availability, accessibility and promotion of unhealthy foods are needed.