Health and well-being are inextricably linked with nutrition. The World Health Organization (2018) identifies healthy diet as a key protective factor against malnutrition and non-communicable diseases. Although a variety of recommendations exist, a healthy diet is defined by the World Health Organization (2018) as following the basic principles of; regular intake of unprocessed fruits, vegetables, nuts, legumes and whole grains and limited intake of free sugars, saturated fats, sodium and processed foods.
There is considerable evidence to show that regular consumption of energy dense, nutrient poor foods is a causative factor of overweight, obesity and chronic disease, particularly diabetes mellitus, cardiovascular disease and some cancers (World Health Organization, 2003). The New Zealand (NZ) Ministry of Health (2012) recognises this as a public health issue and has developed guidelines for healthy eating which are promoted by health professionals and recommended to organisations and individuals.
Despite this knowledge and the subsequent recommendations, NZ has the third highest incidence of obesity among OECD countries, with a rate of over 30 percent of the population (OECD, 2017). The NZ Health Survey 2017/18 found one in eight children aged two to fourteen years are obese (Ministry of Health, 2018). Hospitalisation data has also shown a marked increase in micronutrient deficiencies associated with acute illness in children, highlighting malnutrition together with obesity as an issue related to diet (K. Johnston, 2017).
Achieving healthy diet in children is therefore important for prevention of illness and to protect future health. This not only benefits individuals and families, it benefits society by reducing the burden of diet-related disease on health system resources. Evidence also indicates a healthy diet is associated with improved academic performance in children, therefore may contribute to higher education levels and future opportunities (Florence, Asbridge, & Veugelers, 2008).
Studies have shown eating habits and feeding strategies of caregivers are the most influential factors on children’s diet (Scaglioni et al., 2018), however these are subject to multiple effects such as socioeconomic status and level of education of the caregiver (Patrick & Nicklas, 2005). Schools also play a significant role in socialisation of diet and eating habits through education and peer group influences (Germov, 2014). Schools may be an effective tool in improving children’s current and future diet since they could be regulated and resourced to create consistent healthy food environments.
The NZ Ministry of Education (2014) has developed guidelines for healthy school food programmes which are designed to support and encourage schools to promote healthy eating. These initiatives are voluntary and, as found in the recent national food environments report, not all schools have implemented the guidelines or developed nutrition policies (Vandevijvere, Mackay, & Swinburn, 2017). Healthy eating is currently part of the national school curriculum in NZ (Ministry of Education, 2007) but could potentially be supported and built on by policy which creates food environments congruent with the information being taught.
Historically, unhealthy foods were banned from schools under policies implemented by the Labour-led government in 2006/7, however the ban was lifted by the National government in 2009 (Daly, 2015; M. Johnston, 2006). Concern has been raised that NZ schools are now regularly providing children with unhealthy food for lunches and rewards via canteens, lunch order systems and fundraising (Nursing Review, 2018; Vandevijvere et al., 2017). A symposium for diet-related disease brought this issue to the fore in 2018 with academics calling for nationwide nutrition policies in schools (New Zealand Herald, 2018), a concept which has received public support in recent years (University of Auckland, 2015).
The aim of this review is to determine whether the literature indicates that nutrition policies in schools are associated with reduced consumption of unhealthy food and beverages, and increased consumption of healthy food and beverages by school children. The PECOT model was used to formulate a research question and definition of ‘healthy’ and ‘unhealthy’ adopted from the World Health Organization (2018). Implications of this review are discussed from a nursing perspective and recommendations for practice are made, considering the role of the public health nurse in New Zealand and their involvement in health promotion for schools.
Development of research question
The PECOT model as outlined by Schneider and Whitehead (2013) is used in the following table to develop the research question for this literature review.
Information relating to question
Children attending school (aged 5-18 years) in NZ and other OECD countries
School plays a role in socialisation of eating habits and communication of health messages. The aim of this review is to investigate the effectiveness of formal nutrition policies in schools. Children under 5 years attending early childhood education centres are excluded as they include infants with different nutritional needs and currently have nutrition policies as part of their licensing requirements (Ministry of Education, 2016). School children in other OECD countries are included as outcomes from their policies provide useful information which may be comparable to the NZ setting.
School nutrition policy: formal, deliberate principles formulated to guide decisions related to the food environment in the school
Since current NZ guidelines for schools are not effective, the aim of this review is to investigate whether formal policies implemented in schools have been effective interventions.
The focus of this review is on the outcomes of nutrition policies in schools, without comparison to alternative interventions.
A reduction in consumption of unhealthy foods and beverages, and an increase in consumption of healthy foods and beverages by school children
To determine whether school nutrition policies are associated with improved diet in children and whether their nationwide implementation is warranted.
Time is not applicable to this review as each study and piece of literature will be set over a different timeframe. Policy implementation and its effects occur over long term.
Question: Are nutrition policies in schools associated with reduced consumption of unhealthy, and increased consumption of healthy, foods and beverages by school children?
For the purpose of this review, nutrition policies are defined as formal, deliberate principles formulated to guide decisions related to the food environment in a school.
Unhealthy foods and beverages are defined as; energy dense, nutrient poor foods that are high in saturated fats, free sugars and/or sodium. Healthy foods and beverages are; nutrient dense, unprocessed and low in saturated fat, free sugars and sodium. Water is included as a healthy beverage. (World Health Organization, 2018)
Inclusion criteria: All studies carried out in OECD countries completed in the last 10 years which evaluated outcomes of school nutrition policies. Studies evaluating the outcomes of healthy eating intervention programmes in schools were included. Although not called ‘policies’ these were designed and implemented with deliberate principles formulated to guide decisions related to the school food environment.
Exclusion criteria: early childhood education centres, children under 5 years, adults.
The literature search was carried out using CINAHL and PubMed databases with the keywords; school, nutrition, policy, guideline, regulation, programme, intervention, diet, food, beverage, consumption, child/ren.
Evidence and findings
School nutrition policies and interventions have been developed and studied in few OECD countries over the last 10 years. A search of the literature revealed 12 studies of policy implementation; 2 of which were from NZ, 3 from the United States of America, 2 the United Kingdom, 2 Australian, 2 Canadian and 1 from the European Union.
New Zealand context
The food environment in NZ is somewhat unique compared to these other countries in that school meals are generally not provided under a government funded programme, children typically take packed lunches from home and food supplied at school is mostly sold by canteens, tuck shops and through fundraising. In 2007, the NZ Ministry of Education notified all schools they were required to promote healthy food and nutrition and to make only healthy food and beverage options available for sale on school premises, which led to the implementation of initiatives funded by the public health strategy, ‘Healthy Eating Healthy Action’ (Pledger, McDonald, & Cumming, 2012). A survey of the food environments in NZ primary schools prior to and following implementation of these initiatives revealed 26% of primary schools sold unhealthy food and beverages daily in 2009, a decrease from 36% in 2007 (Pledger et al., 2012). This shows a reduction in the provision of unhealthy food and beverages but does not indicate a change in school children’s consumption of such products.
Similarly, Rush et al. (2011) found availability of healthier food options increased for primary school children in Waikato NZ following a regional intervention programme to bring the school food environment in line with nutritional guidelines, however dietary changes were not assessed.
Nutrition policy implementation
Several studies did not assess children’s dietary intake as an outcome but rather focused on the implementation of nutrition policies by schools. For example, a survey of school principals and stakeholders in Queensland, Australia revealed the state-wide healthy food and drink supply strategy had been implemented successfully and unhealthy foods removed from school’s regular food supply (Dick et al., 2012). Likewise, Yoong et al. (2016) found that close monitoring, audit and feedback on policy implementation significantly reduced the provision of unhealthy foods in schools of New South Wales, Australia. Kubik, Farbakhsh, and Lytle (2013) showed federally-mandated school nutrition policy in the United States was effective in significantly reducing the sale of unhealthy food for school fundraising, and Milder, Mikolajczak, van den Berg, van de Veen-van Hofwegen, and Bemelmans (2014) noted an increase in provision of healthy food following participation of Dutch schools in healthy canteen programmes. However, the latter study did not find a reduction in provision of unhealthy foods (Milder et al., 2014), which highlights the fact that the content of the policy and its target priorities influence the outcomes, and in order to understand the effectiveness of a policy it is important to assess changes in actual dietary intake of school children.
International nutrition policies and changes in children’s dietary intake
Other research has assessed dietary changes associated with school nutrition policy. Fung, McIsaac, Kuhle, Kirk, and Veugelers (2013) carried out a population level study in Nova Scotia, Canada to measure effects of province-wide mandatory school nutrition policy on overall diet quality of 10-year-old children. The aim of the policy was to increase access to healthy food and beverages supplied in public schools. Two years after its full implementation a significant decrease in consumption of sugar-sweetened beverages (SSBs), sodium and total fat was found compared with baseline intake. Habitual intake of fruit and vegetables was also assessed with no significant change observed.
Spence et al. (2013) carried out a similar investigation after food and nutrient based standards became part of mandatory policy for schools in England in 2006. The standards prohibited provision of unhealthy foods and stipulated the nutrient levels required in school meals. The study’s aim was to assess the effect of the policy on nutrient content in primary school children’s total diet and they found statistically significant reductions in saturated fat, total fat and sodium intake as well as an increase in micronutrient intake. These changes were observed in both children eating the school lunches provided and those eating packed lunches although children who ate school lunches had even lower intakes of saturated fat and sodium. It is important to note that Fung et al. (2013) and Spence et al. (2013) both observed improvements in children’s overall habitual intake, including food consumed at home. This may be attributed to the effects of a nutrition education component of the policy on children and caregiver’s decisions. Education regarding nutrition was detailed as part of the policy studied by Fung et al. (2013), however Spence et al. (2013) did not discuss policy content and implementation.
A comparison of nutrient intake at school by children eating school lunches versus those eating packed lunches was also undertaken by Pearce, Wood, and Nelson (2012) after the introduction of food-based standards in secondary schools in England. Consumption of saturated fat was found to be lower and micronutrient intake significantly higher in children eating school lunches compared with those bringing food from home. It may be that direct provision of foods meeting the standards was more effective in this case because the policy was not applied to packed lunches and secondary school students are more likely than primary school children to prepare their own packed lunches based on palatability (Pearce et al., 2012).
Coleman, Shordon, Caparosa, Pomichowski, and Dzewaltowski (2012) took a different approach and assessed the change in foods brought from home after implementation of mandatory nutrition policies to eliminate unhealthy foods in 4 elementary and middle Californian schools. Following intervention, they observed a significant decrease over time in unhealthy foods and beverages being brought from home indicating a positive impact of the policy on decisions made by children and caregivers. The researchers attribute this success to the teachers discouraging unhealthy food from home and modelling of healthy eating by school staff (Coleman et al., 2012).
In urban primary schools in Victoria, Australia, Waters et al. (2017) undertook a clinical trial of a more multi-faceted health promotion and obesity prevention programme which included nutrition strategies applied to all food provided at school and brought from home. These strategies are most relevant to NZ schools as the Australian context is similar in that children take packed lunches and may purchase food at the school canteen or tuck shop. This study emphasised caregiver engagement and focused on changing child and caregiver knowledge and behaviour. The researchers assessed children’s food and beverage intake at school after 3.5 years and found a significantly increased consumption of fruit, vegetables and water as well as a significantly reduced intake of SSBs in participating schools compared with control schools (Waters et al., 2017).
Further evidence of effective policies for food provided at school was found in a systematic review of randomized and quasi-experimental interventions which implemented food quality standards in United States and European schools (Micha et al., 2018). Some interventions involved direct provision of healthy food whilst others enforced healthy standards for school meals and food sales. The study revealed improvements in children’s diet with all policies, despite their variation in content. Those most relevant to the NZ context are policies for food sales which resulted in significantly lower intake of SSBs and energy dense, nutrient poor snacks. Policies targeting school meal programmes resulted in increased habitual fruit consumption and reduced intake of total fat, saturated fat and sodium whilst children’s overall fruit and vegetable intake increased after policies were implemented for direct provision of healthy foods (Micha et al., 2018).
Discussion and implications for practice
Available NZ based research during the period of mandatory nutrition policy shows changes were made to the provision of foods in schools however studies were not specifically conducted on changes in children’s diet. This does highlight a gap in the literature however international studies have been valuable in rendering data for the purpose of this review. Despite variations in policy content, implementation and specific outcomes measured by these studies, it has been found that nutrition policies in schools are associated with reduced consumption of unhealthy, and increased consumption of healthy, foods and beverages by school children.
Studies investigating changes to children’s dietary intake focused on food and beverage types containing nutrients of interest. This provides a picture highly relevant to the definition of healthy and unhealthy food by the World Health Organization (2018). Three studies found a reduction in sodium intake by school children associated with nutrition policies (Fung et al., 2013; Micha et al., 2018; Spence et al., 2013). This is a significant outcome for public health as it is proven to lower blood pressure and reduce risk of future cardiovascular disease (Appel et al., 2015).
Also posing a wide range of public health benefits is the decrease in free sugar intake by reducing consumption of SSBs, as seen by Fung et al. (2013), Micha et al. (2018) and Waters et al. (2017). This is associated with a reduction in risk of tooth decay, type 2 diabetes mellitus, adiposity and cardiovascular disease (The Royal Society of New Zealand, 2016).
The increase in fruit, vegetable and micronutrient intake found by Micha et al. (2018), Pearce et al. (2012), Spence et al. (2013) and Waters et al. (2017) is also an important health outcome as it contributes to preventing illness related to malnutrition (Ministry of Health, 2012).
Whilst not every study focused on the same nutrients, several assessed changes in fat intake and found reductions in total and saturated fat (Fung et al., 2013; Micha et al., 2018; Pearce et al., 2012; Spence et al., 2013). When viewed from a public health perspective this signifies a lowering of risk for adiposity, dyslipidaemia and cardiovascular disease (Te Morenga & Montez, 2017). It is important to note however, that several studies also assessed body mass index and did not find significant changes following nutrition policy implementation (Coleman et al., 2012; Fung et al., 2013; Micha et al., 2018; Waters et al., 2017). This may be due to continuation of poor dietary habits outside of school in those studies which did not assess overall dietary intake. It may also be that although reductions in fat intake were observed, in one study researchers acknowledged the intake still remained above the recommended range for children (Spence et al., 2013). This shows a need for a holistic approach to diet improvement across home and school environments, and for ongoing improvement and monitoring of policies to reinforce and optimise positive dietary changes.
NZ public health and school nurses are currently responsible for providing health assessment, promotion and education in schools (Southern District Health Board, 2019). Should nationwide mandatory nutrition policies be implemented in schools, it would be appropriate for registered nurses to assess, monitor and provide support, education and ongoing quality improvement regarding these policies, according to the scope of practice outlined by Nursing Council of New Zealand (2012). With allocation of additional resources and funding, public health nurses would be in an ideal position to do this as they can gain a holistic view of children’s home and school environments and collaborate with several healthcare professionals, such as nutritionists and dieticians, to achieve the best implementation of national policy at a local level for each school.
It is also within the public health nurse’s scope to advocate for change at a governmental level to achieve healthy environments for populations (Nursing Council of New Zealand, 2012; Public Health Association of New Zealand, 2016). Since most NZ schools do not adhere to the current voluntary food guidelines, the need to establish mandatory and regulated standards appears necessary. Public health aims to promote and maintain health of populations with a focus on prevention (Public Health Association of New Zealand, 2016). Significant reductions in risk factors for disease in populations can be achieved through improving children’s diet, and diet can be improved through school nutrition policy, therefore this is a nationwide change to be advocated for.
The content and focus of a nutrition policy influence its outcomes. As seen by Micha et al. (2018), direct provision of healthy foods is associated with increased consumption of these whilst regulation of food sales targets reduction in intake of unhealthy foods. It appears a multi-faceted approach would be most effective, applying the current NZ food and nutrition guidelines (Ministry of Health, 2012) to supply healthy foods, ban unhealthy foods, provide nutrition education, engage children and caregivers and role-model healthy eating by school staff. Adequate support and education for schools and communities and the allowance for local governance to tailor policy implementation to individual community needs will likely make this process more effective (Ritchie et al., 2018).
Recommendations and rationale
After review of the evidence, the following recommendations can be made related to practice:
Diet-related disease is a serious issue worldwide and NZ has committed to taking measures to address this at a population level. Ensuring children consume a healthy diet can significantly reduce risk of future disease however not all NZ schools are currently maintaining healthy food environments. Evidence suggests school nutrition policies can be implemented successfully and are associated with improvements in children’s diets. Their nationwide development should therefore be a priority in public health for effective investment in the future.
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