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

Young adults transition from adolescence to be responsible for their own lifestyles and dietary behaviours [1]. It has been shown that they consume more energy-dense snacks and sugar sweetened beverages, but less fruits and vegetables than other adults [1, 2]. These unhealthy food habits might be influenced by an obesogenic food environment, and could contribute to excessive weight gain and obesity during young adulthood [1, 2]. Many young adults can be reached in tertiary education institutions, thereby making this one appropriate setting to implement food environment interventions and nutrition programs to assist young adults with dietary behavioural change [3, 4]. As an example, in Australia, 1.7 million people aged 15 to 34 years old were studying for tertiary qualifications in 2016 [5].

Snacking is a prevalent dietary behaviour as a result of frequent meal skipping among young adults, which could independently contribute to weight gain [1, 6]. Vending machines provide easy access to snacks and beverages for younger adults to consume in the universities [7, 8]. Previous studies, including a vending machine audit in 2014 in an Australian university, found that the majority of the products in vending machines were unhealthy foods and beverages [9‐11]. High availability of unhealthy options provides an environment that encourages the sales of unhealthy food products in preference to healthy foods [12].

The common variables of vending machine assessment include accessibility, availability, cost, promotion, and healthfulness criteria to categorise healthy and unhealthy products [7]. Interventions and policies to encourage healthier food choices from vending machines often target some of these variables [8]. Pricing and increasing the availability of healthier options have been identified as the most effective strategies to change consumer buying behaviours [8]. Several interventions have succeeded in increasing the sales of healthy snacks and beverages in university settings, e.g. setting discounts and addition of stickers for low-fat snacks, and labelling the products into different categories based on healthfulness [8].

In June 2014, the Australian and New Zealand governments introduced the Health Star Rating (HSR) which is a voluntary front-of-pack labeling system to assist consumers in comparing the nutritional quality of products in a quick and easy way [13]. Australia has one of the highest prevalences of obesity in the world and the HSR was implemented in response to the growing burden of obesity and weight-related lifestyle diseases [13]. The HSR ranges from half a star to five stars, with more stars indicating a healthier choice. Some state governments within Australia such as New South Wales have been setting benchmarks for availability of healthy food and drinks incorporating the HSR [14]. It is possible the introduction and more widespread adoption of the HSR could result in improvements in the products for sale including within vending machines and might assist better food choices.

The aim of this research was (i) to detect any positive changes in the availability of healthy food and beverage products in university vending machines after the nationwide implementation of the HSR system in Australia in 2014, (ii) to assess the compliance with recommended portion sizes and proportions of healthy (everyday) and unhealthy (occasional) products from the Healthy Food and Drink Framework by the State Ministry of Health [14], and (iii) to compare the cost and promotion of healthy and unhealthy foods between surveys.

The availability of healthy snacks and beverages in the university vending machines improved since the introduction of the HSR in 2014. However, although more varieties of foods and drinks with better nutritional quality were detected in the most recent audit, the proportions of healthy to unhealthy choices were still well below the benchmarks from the State Ministry of Health’s Healthy Food and Drink Framework. In addition, the cost of healthy choices was not yet competitive with unhealthy options in 2017 and promotions for unhealthy choices were prevalent, particularly concerning discretionary snacks.

There was increased variety and availability of snacks and beverages with the HSR of 3.5 stars and above in 2017, but within individual snack vending machines, the majority contained few healthy choices. The exceptions were the seven machines from the new vending company that contained a higher proportion of healthy snacks, but also provided the majority of the snacks with HSR of 3.5 stars and above available in the vending machines on campus. They stocked most of the products that carried the HSR label on their packaging. An actual increase in the number of slots in the vending machines meant the vending system in 2017 provided more access to snacks and drinks, both healthy and unhealthy, for university students compared with 2014.

Since implementation of the voluntary HSR system in 2014, uptake of the system on products sold at four major New Zealand supermarkets has been slow, and it is estimated only 5% of products display the stars on their packages [17]. There was evidence that the HSR system influenced product reformulation and the products that displayed the system on their packages, had a more favourable nutrient profile than before the system was implemented [17]. In the vending machines audited, 8.6% of products displayed the stars in 2017 and of the 26 products displaying it, 24 had 3.5 stars or more. Thus as was found in supermarkets only those with favourable profile carry the stars. Some food companies reported challenges in the implementation of the HSR system, such as difficulties in HSR calculation and additional costs on packaging and human resources as reasons for not implementing it [18]. The authors had no difficulty applying the instructions provided by the Australian Government HSR Calculator guidelines for industry. Clearly the scheme will fail to achieve its aim of improving food choices by the public unless it is widely adopted. Mandatory regulation on the HSR system would appear to be needed.

Providing healthier options can change consumer sales towards healthy foods [8, 19]. Consumers have already expressed interest in salads, fresh fruit, and yogurt [20, 21]. Foods with shorter shelf-life require refrigeration but this is no longer the technical obstacle in storing snacks that it was previously [19]. The difficulties in finding products with long shelf-life, appropriate package size and competitive prices for vending systems [22] are becoming less. There are an increasing number of vending companies that provide healthy options both in Australia and USA [23, 24]. Consequently, it is recommended these types of vending companies replace the current contractor’s machines which contained 90% unhealthy choices. For example, if the university food service operator contracted solely the vending machine company that supplied the seven new machines, then healthy options would comprise 40% of vending machine contents, which is a step closer to the 75% the framework recommended [14].

Portion size is not considered in the HSR system, but products with 3.5 stars and above should not be consumed without restriction. Large portion sizes have been implicated in the obesity epidemic [25, 26]. Therefore, the State Ministry of Health’s Framework provides portion limits for several energy-dense food categories, such as nuts and chocolate [14]. Diet beverages failed to meet the recommended volumes. Substituting these drinks with smaller containers might be a feasible intervention [22]. The same strategy could also be the first step to gradually prohibit sugar-sweetened beverages in the university vending system. Unhealthy snacks need to be served in smaller packages as well, but a group of interventions should be implemented simultaneously to prevent increases in purchases which might be stimulated by smaller portions [11].

Cost has been found to be an important factor that affects food choices from vending machines, particularly when purchasing healthier food items [27]. In Mexico, a two-year sustained reduction of sugar-sweetened beverage consumption was found as a result of taxation [28]. The World Health Organization has called for taxes on sugar-sweetened beverages to be implemented internationally [29]. To encourage more purchases of healthy options, price discounts may attract more university students to change their food choices. A study from the USA indicated that a price reduction of 10% was able to assist consumers in making better food choices without compromising the profits [30]. Slightly increasing the price of unhealthy options simultaneously was suggested as another potential strategy to expand the price gap and maintain the revenues [30].

There is an urgent need to protect young adults who are susceptible and frequently targeted by food companies’ marketing but are quite often forgotten in public health initiatives [31]. The proportion of advertisements on unhealthy items remained high, especially for snacks. Although the new vending company machines contained promotions for healthy options, they also claimed to contain no junk foods. However, our study demonstrated that more than half of the snacks offered had a HSR below 3.5 stars. Promotions for unhealthy foods and drinks are not permitted according to the Framework for the State government health facilities and schools [14, 32]. However, these policies are not in place in universities and the onus is on universities to set their own policies targeting young adults who are vulnerable to food promotions [31].

Providing nutritional labelling at the point-of-purchase has been utilized as a part of intervention strategies in many studies [8]. The design of vending machines can make the original nutritional information on the packages invisible for customers [33], and thus extra labelling on or inside the machines might make it easier for them to choose healthier products. The stickers for protein source and nuts in the new machines were good examples, and more should be incorporated into the whole vending system. Stickers for the slots of those snacks and drinks with 3.5 stars and above could be a feasible method.

A combination of strategies has been suggested as the most cost-effective way to create a food environment which makes healthy food choices easier for consumers [11, 34]. This may include increasing the availability and reducing the cost of healthy options, forbidding promotions on unhealthy foods and decreasing their portion sizes. Additionally, it is extremely important to engage stakeholders, such as vending companies, decision-makers in the universities and students [35]. To guarantee the sustainable effect of any such interventions, follow-up studies are necessary to evaluate the compliance and adjust the plan accordingly [36].

This study is the first one to apply the HSR system to assess food products in vending machines in an Australian university. The two time points selected allowed detection of changes before and 3 years after implementation of the HSR system. A strength of the study is that all vending machine data was collected by researchers in audits, rather than reports from the vending company. Moreover, the calculations of the HSR for every product were verified by using the HSR Calculator on the official government website. The results from this study are generalizable for other Australian universities which are known to use the same primary vending suppliers as a common organization facilitates the contractual agreement for almost all tertiary education institutions in Australia.

One of the limitations of the current study is the lack of sales data, and it is unknown if sales of healthy versus unhealthy items has increased. During the process of calculating the HSR, there were some estimations for the proportions of fruits, vegetables, nuts and legumes that had to be made due to insufficient details from the ingredient lists. A registered dietitian was responsible for this analysis and the overall results of these products are not expected to be significantly affected. Ideally, setting up a control group would facilitate the demonstration of internal validity, but the HSR system was implemented simultaneously across the country which prohibited this. However, the limited effect of the current policy was clearly indicated by our findings.

Healthy snacks and beverages have become more available in university vending machines in 2017 compared to 2014, but fell well short of the Framework to achieve a healthy food environment. The introduction of the voluntary HSR food labeling system failed to provide substantial improvements in the nutritional quality of products offered and few products carried the label on their packaging. Some progress has been made in beverages offered, but healthy snacks were more available only because of the introduction of some new vending machines by a small company interested in selling healthy products. Machines operated by the largest suppliers for Australian universities remained unchanged. Policy directives may be necessary for further improvements in the availability of healthy foods and drinks with competitive pricing and better promotions, to facilitate healthier food choices amongst young adults in tertiary education institutions. Regulation rather than a voluntary system for displaying HSR would appear to be necessary.