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.

Nutritional quality of snacks and beverages sold through vending machines in a large Hispanic-serving urban college campus in the United States: A cross-sectional study

Students from nutritionally-vulnerable neighborhoods face dietary challenges through built environment of college vending machines. In this cross-sectional study, snacks and beverages sold in vending machines for a 4-week period in a Bronx-based Hispanic-serving college were recorded. Nutritional information was recorded from nutrition labels. Proportion of low- and high-sodium foods, "smart snacks" with a limit of 200 kcal and 200 mg of sodium, and foods with added sugar were recorded. Snacks had significantly higher calories and sodium per serving (227 kcal, 208 mg) than beverages (132 kcal, 90 mg) (t-test, p < 0.001). Almost a third of the snacks (32%) qualified as "smart snacks" for calories and 62% qualified as "smart snacks" for sodium. Beverages contained less than half the number of ingredients as snacks. About 53% of beverages and almost 60% of snacks listed sugar among the first five ingredients. Results underscore the need for colleges to promote less-processed entities with less added sugar.

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.

Vending Machines and Cardiovascular Prevention: How to Implement Healthy Dietary Habits at School

Too many children in Europe are overweight. The unregulated marketing of unhealthy products target to children, and the installation of vending machines stocked with unhealthy snacks in public venues, are contributing factors. While innovative legislation on the regulation of the nutritional quality of food and beverages sold in vending machines in schools has become law in some European countries, it is not on the political agenda in others. However, an easy alternative solution could be to introduce a clause in all new tenders for vending machines, which states that the successful supplier must commit to ensuring that at least 50% of the products sold have a medium-to-small portion size, are low in saturated fat, salt, calories, and have no added sugar. This strategy, called "A vending machine for a friend", was developed at CNR of Rome, and with the support of the SIPREC, the LHA and the EHN, and with the alliance with teachers and students, is being rolled out in some Italian and Lithuanian high schools. Creating a healthy nutritional environment with the aim of encouraging healthier choices, is a real possibility.

Healthier school food and physical activity environments are associated with lower student body mass index

School food and physical activity (PA) environments can influence children’s dietary and physical activity behaviors. However, evidence on whether school environment is associated with students’ weight status is less definitive. In this study, we examined the association between students’ body mass index (BMI) and measures of school food and PA environments. We calculated BMI from nurse-measured data collected on 19,188 6–19-year-old students from 90 public schools in four low-income cities in New Jersey in 2015–2016. Based on a questionnaire administered to school nurses, we constructed 6 food and 3 PA indices capturing the healthfulness of key dimensions in the school food and PA environment domains. Multilevel linear models, stratified by school level (elementary and secondary), examined the association between BMI z-scores and indices of the school environment. The food and PA domains were modeled separately and then combined. Joint significance of indices within each domain was tested. Analyses were conducted in 2019–2020. In the combined model for elementary schools, indices in both the food and PA domains were jointly significant (p = 0.005 and p < 0.001, respectively). With regard to specific indices in the model, students’ BMI z-score was 0.03 units lower for each additional outdoor PA facility (95% CI [−0.06, −0.00]; p = 0.036). Similarly, for secondary schools, both the food and PA domains were jointly significant (p = 0.004 and p = 0.020, respectively). Each additional unhealthy item in vending machines was associated with a 0.12 unit increase in BMI z-score (95% CI [+0.00, 0.23]; p = 0.042). Overall, healthier food and PA environments were associated with lower student BMI.

Application of nutrient profile models to compare products offered in 'healthy' vs 'conventional' vending machines in a Spanish hospital environment

INTRODUCTION

Vending machines promote easy access to food with low nutritional value. 'Healthy' vending machines (HVM) have been introduced as a means to improve the availability and accessibility of healthy food options, and the healthiness of the foods, however, has not been evaluated.

OBJECTIVE

Our aim was to assess the healthiness of the products offered in HVM and 'conventional' vending machines (CVM), located in the Catalan Institute of Oncology.

STUDY DESIGN AND METHODS

All products available in vending machines (HVM (n = 33) and CVM (n = 62) were evaluate during three nutrient profile models (NPMs): the World Health Organization's European Regional Office model (WHO), Nutrient Profile Model UK (NPM-UK), and Australian Health Star Rating system (HSR).

RESULTS

Regardless of the NPM used, significant differences found in the proportion of healthy products among HVM and CVM (WHO: P-value = 0.005, NPM-UK: P value < 0.001, HSR: P-value < 0.001). The healthy products offered in HVM accounted for 30%, 73%, and 52% of the total content, while CVM offered 6%, 32%, and 15% of the content, as assessed by WHO, NPM-UK, and HSR, respectively. The WHO model was the most restrictive model, and the NPM-UK was the most permissible one.

CONCLUSIONS

Although not all products in HVM are rated as healthy by the different NPMs, the percentage of healthy products was significantly higher than those in CVM.

less healthy items in UK hospital vending machines: a multiple treatment reversal design

BACKGROUND

Altering the availability of healthier or less-healthy products may increase healthier purchases, but evidence is currently limited. The current study aimed to investigate the impact of altering the absolute-and-relative availability of healthier and less-healthy products - i.e. simultaneously altering the number of options available and the proportion of healthier options - in hospital vending machines.

METHODS

An adapted multiple treatment reversal design was used, altering products available in ten vending machines serving snack foods and/or cold drinks in one English hospital. Machines were randomised to one of two sequences for the seven 4-week study periods: ABCADEA or ADEABCA. In Condition A (study periods 1, 4 and 7) the proportions of healthier products were standardised across all machines, so that 25% of all snack slots and 75% of drink slots were healthier. In Condition B, 20% of vending machine slots were emptied by removing less-healthy products. In Condition C, the empty slots created in Condition B were filled with healthier products. Conditions D and E were operationalised in the same way as B and C, except healthier products were removed in D, and then less-healthy products added in E. Sales data were obtained from machine restocking records. Separate linear mixed models were conducted to examine the impact of altering availability on energy purchased (kcal) from (i) snacks or (ii) drinks each week, with random effects for vending machine.

RESULTS

The energy purchased from drinks was reduced when the number of slots containing less-healthy drinks was decreased, compared to standardised levels (- 52.6%; 95%CI: - 69.3,-26.9). Findings were inconclusive for energy purchased from snacks when less-healthy snack slots were reduced (- 17.2%; 95%CI: - 47.4,30.5). Results for altering the number of slots for healthier drinks or snacks were similarly inconclusive, with no statistically significant impact on energy purchased.

CONCLUSIONS

Reducing the availability of less-healthy drinks could reduce the energy purchased from drinks in vending machines. Further studies are needed to establish whether any effects might be smaller for snacks, or found with higher baseline proportions of healthier options.

School Food and Physical Activity Environment: A Longitudinal Analysis of Four School Districts in New Jersey

PURPOSE

Exposures to favorable environments in childhood, including those in schools, are associated with healthy habits among children. In this study, we developed a series of indices aimed at measuring students' exposure to different dimensions of the school food and physical activity (PA) environment. We implemented these indices to investigate how different aspects of the school food and PA environment changed over time and examined their correspondence with known changes in relevant policies and programs.

METHODS

All public schools (n= 141) in four school districts in New Jersey provided detailed food and PA environment data for each school year from 2010-2011 to 2015-2016. Seven food environment indices, three PA environment indices, and two additional indices that capture health-promoting initiatives at the school level and at the state or federal level were developed.

RESULTS

Although the school PA environment largely remained unchanged, several dimensions of the school food environment changed between 2010-2011 and 2015-2016. Overall, the number of healthy items increased over time in vending machines (p < .001), a la carte (p < .05), or through reimbursable school lunches (p < .001); decreases in number of unhealthy items were only detected in school lunches (p < .05). For most food indices, both the number of items offered and the trend over time varied across school levels.

CONCLUSIONS

Schools are a key venue for implementing policy and environment interventions aimed to promote healthy behaviors. Indices developed from easy-to-use survey questions captured multiple dimensions of the school food and PA environments and were sensitive to policy changes over time.

The effect of spine discomfort on the overall postural (dis)comfort

Currently, the word 'comfort' is often used in relation to the marketing of products such as chairs, cars interiors, clothing, hand tools and even airplane tickets. In this field of research, the aim of this study is to investigate the influence of spinal posture on postural (dis)comfort perception; the test case is the analysis of the interaction between humans and vending machines for purchasing food or beverages. A statistical sample of 20 healthy students (subjects) performed the required tests, with each participant asked to take a product from three different vending machines (snacks, drinks and coffee). The subjects' postures were acquired non-invasively using cameras; software and instruments for virtual prototyping were used for posture analysis and interaction modelling, both questionnaires (subjective) and comfort-analysis software (objective) were used to rate the perceived (dis)comfort. The results obtained from simulations and questionnaires were compared, and a method to weigh the effect of the perceived spinal discomfort on overall postural (dis)comfort was proposed. These results reveal a good correlation between subjective perception and objective evaluation obtained through simulations, confirming the validity of the proposed method.

Examining changes in school vending machine beverage availability and sugar-sweetened beverage intake among Canadian adolescents participating in the COMPASS study: a longitudinal assessment of provincial school nutrition policy compliance and effectiveness

Background

School nutrition policies can encourage restrictions in sugar-sweetened beverage (SSB) availability in school food outlets in order to discourage students’ SSB intake. The main objective was to examine how beverage availability in school vending machines changes over three school years across schools in distinct school nutrition policy contexts. Secondary objectives were to examine how students’ weekday SSB intake varies with time and identify longitudinal associations between beverage availability and SSB intake.

Methods

This longitudinal study used data from the COMPASS study (2013/14–2015/16), representing 7679 students from 78 Canadian secondary schools and three provincial school nutrition policy contexts (Alberta – voluntary guidelines, Ontario public – mandatory guidelines, and Ontario private schools – no guidelines). We assessed availability of 10 beverage categories in schools’ vending machines via the COMPASS School Environment Application and participants’ intake of three SSB varieties (soft drinks, sweetened coffees/teas, and energy drinks) via a questionnaire. Hierarchical regression models were used to examine whether: i) progression of time and policy group were associated with beverage availability; and, ii) beverage availability was associated with students’ SSB intake.

Results

Ontario public schools were significantly less likely than the other policy groups to serve SSBs in their vending machines, with the exception of flavoured milks. Vending machine beverage availability was consistent over time. Participants’ overall SSB intake remained relatively stable; reductions in soft drink intake were partially offset by increased sweetened coffee/tea consumption. Relative to Ontario public schools, attending school in Alberta was associated with more frequent energy drink intake and overall SSB intake whereas attending an Ontario private school was associated with less frequent soft drink intake, with no differences in overall SSB intake. Few beverage availability variables were significantly associated with participants’ SSB intake.

Conclusions

Mandatory provincial school nutrition policies were predictive of more limited SSB availability in school vending machines. SSB intake was significantly lower in Ontario public and private schools, although we did not detect a direct association between SSB consumption and availability. The findings provide support for mandatory school nutrition policies, as well as the need for comprehensive school- and broader population-level efforts to reduce SSB intake.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0754-5) contains supplementary material, which is available to authorized users.

Impact of tax and subsidy framed messages on high- and lower-sugar beverages sold in vending machines: a randomized crossover trial

OBJECTIVE

Framing of fiscal incentives has been suggested to be important in influencing purchase decisions. We aimed to examine the effect of framing a modest price difference between high- and lower-sugar beverages as a tax or a subsidy respectively, using messages placed on vending machines to influence beverage purchases.

DESIGN/SETTING

This is an 11-week randomized crossover trial conducted between August and November 2015, with a two-week run-in period before intervention, targeted at students, staff and faculty of a university campus in Singapore. Twenty-one beverage vending machines were used to implement the intervention involving 'tax message', 'subsidy message' and 'no message (control)'. The former two messages suggest 'a tax for high sugar beverages' or 'a subsidy for lower sugar beverages' respectively. Prices of the beverages offered were fixed at baseline and remained the same in all three experimental conditions: lower-sugar beverage options were priced ~ 10% lower than the corresponding high-sugar option. The machines were randomized to one of the 6 sequences of intervention. Each message intervention period was 3 weeks. The effect of messages was assessed by comparing average weekly units of beverages sold between interventions using mixed effects model.

RESULTS

The average weekly units of high and lower-sugar beverages sold per vending machine were 115 and 98 respectively in the control condition. The percentage of high-sugar beverages sold was 54% in the control, 53% in the tax, and 54% in the subsidy message condition. There was no difference in the weekly units of high-sugar beverages sold for the tax message (- 2, 95% CI -8 to 5, p = 0.61) or the subsidy message (0, 95% CI -10 to 10, p = 0.96) conditions as compared with the control condition. Similarly, there was no difference in the weekly units of lower-sugar beverages sold for the tax message (4, 95% CI -4 to 13, p = 0.32) or the subsidy message (7, 95% CI -4 to 18, p = 0.18) conditions as compared with the control condition.

CONCLUSIONS

The use of tax and subsidy messages to highlight modest price differences did not substantially reduce high-sugar beverage sales in vending machines on an Asian university campus.

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.

Sales of healthy snacks and beverages following the implementation of healthy vending standards in City of Philadelphia vending machines

OBJECTIVE

We examined outcomes following the implementation of employer-wide vending standards, designed to increase healthy snack and beverage options, on the proportion of healthy v. less healthy sales, sales volume and revenue for snack and beverage vending machines.

DESIGN

A single-arm evaluation of a policy utilizing monthly sales volume and revenue data provided by the contracted vendor during baseline, machine conversion and post-conversion time periods. Study time periods are full calendar years unless otherwise noted.

SETTING

Property owned or leased by the City of Philadelphia, USA.

SUBJECTS

Approximately 250 vending machines over a 4-year period (2010-2013).

RESULTS

At post-conversion, the proportion of sales attributable to healthy items was 40 % for snacks and 46 % for beverages. Healthy snack sales were 323 % higher (38·4 to 162·5 items sold per machine per month) and total snack sales were 17 % lower (486·8 to 402·1 items sold per machine per month). Healthy beverage sales were 33 % higher (68·2 to 90·6 items sold per machine per month) and there was no significant change in total beverage sales (213·2 to 209·6 items sold per machine per month). Revenue was 11 % lower for snacks ($US 468·30 to $US 415·70 per machine per month) and 21 % lower for beverages ($US 344·00 to $US 270·70 per machine per month).

CONCLUSIONS

Sales of healthy vending items were significantly higher following the implementation of employer-wide vending standards for snack and beverage vending machines. Entities receiving revenue-based commission payments from vending machines should employ strategies to minimize potential revenue losses.

Health Promotion and Healthier Products Increase Vending Purchases: A Randomized Factorial Trial

BACKGROUND

The current food environment has a high prevalence of nutrient-sparse foods and beverages, most starkly seen in vending machine offerings. There are currently few studies that explore different interventions that might lead to healthier vending machine purchases.

OBJECTIVE

To examine how healthier product availability, price reductions, and/or promotional signs affect sales and revenue of snack and beverage vending machines.

DESIGN

A 2×2×2 factorial randomized controlled trial was conducted.

PARTICIPANTS/SETTING

Students, staff, and employees on a university campus.

INTERVENTION

All co-located snack and beverage vending machines (n=56, 28 snack and 28 beverage) were randomized into one of eight conditions: availability of healthier products and/or 25% price reduction for healthier items and/or promotional signs on machines. Aggregate sales and revenue data for the 5-month study period (February to June 2015) were compared with data from the same months 1 year prior. Analyses were conducted July 2015.

MAIN OUTCOME MEASURES

The change in units sold and revenue between February through June 2014 and 2015.

STATISTICAL ANALYSES PERFORMED

Linear regression models (main effects and interaction effects) and t test analyses were performed.

RESULTS

The interaction between healthier product guidelines and promotional signs in snack vending machines documented increased revenue (P<0.05). Beverage machines randomized to meet healthier product guidelines documented increased units sold (P<0.05) with no revenue change. Price reductions alone had no effect, nor were there any effects for the three-way interaction of the factors. Examining top-selling products for all vending machines combined, pre- to postintervention, we found an overall shift to healthier purchasing.

CONCLUSIONS

When healthier vending snacks are available, promotional signs are also important to ensure consumers purchase those items in greater amounts. Mitigating potential loss in profits is essential for sustainability of a healthier food environment.

Study of Acrylamide Level in Food from Vending Machines

Acrylamide is a by-product of the Maillard reaction and is potentially carcinogenic to humans. It is found in a number of foods with higher concentrations in carbohydrate-rich foods and moderate levels of protein-rich foods such as meat, fish and seafood. Acrylamide levels in food distributed in vending machines placed in public areas of the city of Perugia were analysed by high-performance liquid chromatography. Samples included five different categories, depending on the characteristics of the products: i) potato chips; ii) salted bakery products; iii) biscuits and wafers; iv) sweet bakery products; v) sandwiches. A high variability in acrylamide level among different foods and within the same category was detected. Potato chips showed the highest amount of acrylamide (1781±637 μg/kg) followed by salted bakery products (211 ±245 μg/kg), biscuits and wafers (184±254 μg/kg), sweet bakery products (100±72 μg/kg) and sandwiches (42±10 μg/kg). In the potato chips and sandwiches categories, all of the samples revealed the presence of acrylamide, while different prevalence was registered in the other foods considered. The data of this study highlight the presence of acrylamide in different foods sold in vending machines and this data could be useful to understand the contribution of this type of consumption to human exposure to this compound.

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.

and Listeria Monocytogenes Contamination in Ready-To-Eat Sandwiches Collected from Vending Machines

Ready-to-eat (RTE) food is characterised by a long shelf-life at refrigerated temperature and can be consumed as such, without any treatment. The aim of the work was to evaluate the presence of Listeria spp. and Listeria monocytogenes in RTEs collected from refrigerated vending machines placed in hospital environment and accessible to the hospitalised patients. In 4 different sampling, 55 RTEs were collected from vending machines of six hospitals located in different areas of Sardinia region. All the samples were characterised by similar manufacturing process, such as the use of modified atmosphere packaging and belonged to 5 different producers. Listeria spp. was not countable using the enumeration method in all of the analysed samples. Using the detection method, Listeria spp. was recovered from 9 sandwich samples. Interestingly, 3 of these samples (5.5%) made by the manufacturer, were positive for L. monocytogenes contamination. The risk related to the L. monocytogenes presence in RTEs proportionally increases when food is introduced in susceptible environments, such as hospitals and consumed by susceptible people. Although the RTEs analysed showed values that complied with the European microbiological criteria for foodstuffs, the availability of these products in a susceptible environment should be carefully checked. Therefore, in order to limit the possible exposition to L. monocytogenes, more information on the risk related to RTE consumption should be provided to the hospitalised patients.

Nutritional value of foods sold in vending machines in a UK University: Formative, cross-sectional research to inform an environmental intervention

Vending machine use has been associated with low dietary quality among children but there is limited evidence on its role in food habits of University students. We aimed to examine the nutritional value of foods sold in vending machines in a UK University and conduct formative research to investigate differences in food intake and body weight by vending machine use among 137 University students. The nutrient content of snacks and beverages available at nine campus vending machines was assessed by direct observation in May 2014. Participants (mean age 22.5 years; 54% males) subsequently completed a self-administered questionnaire to assess vending machine behaviours and food intake. Self-reported weight and height were collected. Vending machine snacks were generally high in sugar, fat and saturated fat, whereas most beverages were high in sugar. Seventy three participants (53.3%) used vending machines more than once per week and 82.2% (n 60) of vending machine users used them to snack between meals. Vending machine accessibility was positively correlated with vending machine use (r = 0.209, P = 0.015). Vending machine users, compared to non-users, reported a significantly higher weekly consumption of savoury snacks (5.2 vs. 2.8, P = 0.014), fruit juice (6.5 vs. 4.3, P = 0.035), soft drinks (5.1 vs. 1.9, P = 0.006), meat products (8.3 vs. 5.6, P = 0.029) and microwave meals (2.0 vs. 1.3, P = 0.020). No between-group differences were found in body weight. Most foods available from vending machines in this UK University were of low nutritional quality. In this sample of University students, vending machine users displayed several unfavourable dietary behaviours, compared to non-users. Findings can be used to inform the development of an environmental intervention that will focus on vending machines to improve dietary behaviours in University students in the UK.

Vending machine assessment methodology. A systematic review

The nutritional quality of food and beverage products sold in vending machines has been implicated as a contributing factor to the development of an obesogenic food environment. How comprehensive, reliable, and valid are the current assessment tools for vending machines to support or refute these claims? A systematic review was conducted to summarize, compare, and evaluate the current methodologies and available tools for vending machine assessment. A total of 24 relevant research studies published between 1981 and 2013 met inclusion criteria for this review. The methodological variables reviewed in this study include assessment tool type, study location, machine accessibility, product availability, healthfulness criteria, portion size, price, product promotion, and quality of scientific practice. There were wide variations in the depth of the assessment methodologies and product healthfulness criteria utilized among the reviewed studies. Of the reviewed studies, 39% evaluated machine accessibility, 91% evaluated product availability, 96% established healthfulness criteria, 70% evaluated portion size, 48% evaluated price, 52% evaluated product promotion, and 22% evaluated the quality of scientific practice. Of all reviewed articles, 87% reached conclusions that provided insight into the healthfulness of vended products and/or vending environment. Product healthfulness criteria and complexity for snack and beverage products was also found to be variable between the reviewed studies. These findings make it difficult to compare results between studies. A universal, valid, and reliable vending machine assessment tool that is comprehensive yet user-friendly is recommended.

Soda consumption during ad libitum food intake predicts weight change

Soda consumption may contribute to weight gain over time. Objective data were used to determine whether soda consumption predicts weight gain or changes in glucose regulation over time. Subjects without diabetes (128 men, 75 women; mean age 34.3±8.9 years; mean body mass index 32.5±7.4; mean percentage body fat 31.6%±8.6%) self-selected their food from an ad libitum vending machine system for 3 days. Mean daily energy intake was calculated from food weight. Energy consumed from soda was recorded as were food choices that were low in fat (<20% of calories from fat) or high in simple sugars (>30%). Food choices were expressed as percentage of daily energy intake. A subset of 85 subjects had measurement of follow-up weights and oral glucose tolerance (57 men, 28 women; mean follow-up time=2.5±2.1 years, range 6 months to 9.9 years). Energy consumed from soda was negatively related to age (r=-0.27, P=0.0001) and choosing low-fat foods (r=-0.35, P<0.0001), but positively associated with choosing solid foods high in simple sugars (r=0.45, P<0.0001) and overall average daily energy intake (r=0.46, P<0.0001). Energy intake from food alone did not differ between individuals who did and did not consume beverage calories (P=0.11). Total daily energy intake had no relationship with change in weight (P=0.29) or change in glucose regulation (P=0.38) over time. However, energy consumed from soda correlated with change in weight (r=0.21, P=0.04). This relationship was unchanged after adjusting for follow-up time and initial weight. Soda consumption is a marker for excess energy consumption and is associated with weight gain.