teaching healthy eating to primary school students

LR_15130_220115

January 2015

FU L L REP O R T

TEACHING HEALTHY EATING TO PRIMARY SCHOOL STUDENTS A RE V IE W OF E V I DENCE AN D BEST PR ACT ICE

NSW Department of Education and Communities | Teaching Healthy Eating to Primary School Students

www.dec.nsw.gov.au

This report was prepared for the NSW Department of Education and Communities with funding provided by the NSW Ministry of Health as part of the Healthy Children’s Initiative. The Department would like to acknowledge the SAX Institute for commissioning and coordinating the review and the following researchers from Sydney University and Macquarie University for conducting the review: Dr Dean Dudley – Macquarie University Dr Louisa Peralta – University of Sydney Dr Wayne Cotton – University of Sydney Dr David Baxter – Editorial Consultant

For further information please contact Student Engagement and Interagency Partnerships Unit NSW Department of Education and Communities 1 Oxford Street, Darlinghurst 2010 Tel: 9266 8258

This review includes the Teaching healthy eating to primary school students: A review of evidence and best practice: Short report, which highlights the findings of studies published between 2004 and 2014 within this review and summarises the key finding and messages.


www.dec.nsw.gov.au

2

Introduction The New South Wales Ministry of Health (2013)7 reported that 22.8% of children in NSW (24% of boys and 21.5% of girls) were overweight or obese in 2010. Projections suggest that, should no action be taken to address the issue, 68% of adult males and 54% of adult females in NSW will be classified as overweight or obese by 2016. The National Health and Medical Research Council (2013)1 states that optimum nutrition is essential for the healthy growth and development of children and therefore healthy eating is a critical behavioural risk factor that can have a significant impact on well-being at all ages. Optimum nutrition is essential for the healthy growth and development of infants and children. Healthy eating contributes to achieving and maintaining a healthy weight, and provides protection against chronic disease and premature mortality. Conversely, unhealthy eating, in particular the over-consumption of energy-dense, nutrient-poor foods and drinks, as well as physical inactivity and a sedentary lifestyle, are predictors of overweight and obesity. Healthy eating by children and young people is important in order to obtain adequate amounts of nutrients essential for good health, growth and development. It is also important to establish these healthy eating behaviours early, as evidence shows that eating habits and patterns track into adulthood (Neumark-Sztainer, Wall, Larson, Eisenberg & Loth, 2011; Nicklaus & Remy, 2013)8,9. Therefore, childhood is a period when education about healthy eating is essential for establishing healthy eating practices in later years.

This review aims to synthesise the research evidence in relation to five key questions concerning the implementation of healthy eating education in primary schools: 1. What strategies does the evidence indicate are most effective in teaching healthy eating to primary school children? 2. F or the strategies identified in question 1, what level of support is required for teachers to deliver them? 3. What is the extent to which each strategy has teaching resources? 4. W hat are the limitations or gaps in healthy eating resources currently available? 5. W hat do the experts say are the most effective approaches and strategies in teaching healthy eating to primary school-aged children? The review provides discussions of each question in turn with a focus on relevant research literature, followed by a concluding section which synthesises the themes of the research and determines the most effective, practical and appropriate strategies available to education systems, schools and teachers, in response to the evidence.

There is good evidence that obesity and many non-communicable diseases (such as diabetes, osteoporosis, and hypertension) are related to nutrition habits formed during childhood (Popkin & Gordon-Larsen, 2004)10. Schools have been a popular setting for the implementation of health promotion interventions, as they offer continuous, intensive contact with children (Gill, King & Webb, 2005; Khambalia et al, 2012)3,4 and lifelong health and wellbeing begins with promoting healthy behaviours early in life (Lee, 2009)5. School infrastructure, physical environment, policies, curricula, teaching and learning, and staff have the potential to positively influence child health.


www.dec.nsw.gov.au

3

Question 1: What strategies does the evidence indicate are most effective in teaching healthy eating with K-6 students? This section of the review focuses on studies that have identified the effectiveness of a range of strategies in teaching healthy eating to primary school-aged children.

Methods Inclusion criteria Participants This review included primary/elementary school-aged children.

Interventions We included teaching or school-based interventions delivered by teachers or teacher substitutes that sought to bring about positive nutritional behaviour or knowledge change in primary school children. The following types of teaching and school-based interventions were included: 1. Curriculum initiatives or evaluations 2. Nutrition-friendly school initiatives 3. Community programs linked to curricula or delivered by schools (e.g. community gardens) 4. H ealth/nutrition education programs related to improving dietary habits 5. Environmental school change strategies implemented by classroom teachers 6. Environmental interventions/industry partnerships focused on point-of-purchase consumption linked through classroom based education; this might include campaigns to draw attention to healthier products in school canteens or school lunch choices 7. Social marketing campaigns 8. Policies that seek to improve dietary habits of primary school children (i.e. school board level, provincial/ national level).

Locations Intervention locations had to include primary schools or their immediate community settings. We excluded programs or strategies delivered solely through homes, churches, non-governmental organisations, primary health care settings, universities, hospitals, outpatient clinics located within hospital settings, commercial programs and metabolic or weight loss clinics. Outcomes of interest Our primary outcomes included measures of both access to and consumption of nutrient dense foods. Evidence of intervention effects included measures at individual, family, school or community levels. Measures of food consumption, preference or knowledge and change in food environments, food disappearance, and food sales (in school cafeterias) were included. Food supply measures included information about which food items are distributed to different regions and areas. Market inventory refers to records a food supply organisation keeps about which foods are being ordered or are available. Measures of consumption included: diet and food intake records, self-reported and/or reported by parents, teachers or both; food frequency questionnaires/ balance sheets; food wastage and plate waste; and micronutrient measures (i.e., biomarkers of exposure to food). Measures of preference included questionnaires, surveys or self-report instruments that included Likert scales, pairing activities, or self-reported preferences. Measures of knowledge included questionnaires or tests on food-related knowledge (i.e. Recommended Dietary Intakes, ingredients, nutritional knowledge).

Study designs Acceptable designs for this review included randomised and non-randomised studies (including cluster-controlled and controlled time series), interrupted time series (to assess changes that occur over time), and before-after studies with control groups. Relevant clusters within studies, included individuals, classrooms, schools or communities as the unit of analysis.


www.dec.nsw.gov.au

2

Question 1 (continued) Search strategy Our search strategy included: electronic bibliographic databases; grey literature databases; reference lists of key articles; targeted internet searching via Google Scholar; and targeted internet searching of key organisation websites. We searched the following databases, adapting search terms according to the requirements of individual databases in terms of subject heading terminology and syntax: PUBMED; MEDLINE; the Cochrane Central Register of Controlled Trials (CENTRAL); PsycINFO; ERIC; ScienceDirect; and A+Education. Dates ranges for studies included were from database inception to 31st May, 2014. Whilst studies dating as far back as 2004 were requested by the brokering agencies, the researchers believed that high quality studies (i.e. randomised controlled trials, quasi-experimental studies, and clustercontrolled studies) are rare in K-6 school settings and for this reason the quality of the study was more influential in determining inclusion.

Retrieval of teaching strategies from literature Three of the researchers reviewed each of the articles independently and each identified the teaching approaches employed in the intervention phase of the studies. Researchers met and cross-referenced their identification of each teaching approach and decided though consensus how each approach would be classified as a wider teaching strategy that would allow for comparison between studies in order to answer the review questions.

Results Citation retrieval The study initially retrieved in excess of 200,000 possible citations. We refined searches to include only full text copies available online and published after 1970 in each of the databases and in Google Scholar reducing this to 18,100 possible citations. These citations were then cross-referenced electronically with reference lists from scoping and systematic review papers published in the field of nutrition, education, and health promotion (n=15) published between 1997 and 2012 which yielded 454 likely studies. A final database and internet search was then conducted to identify studies published between January 2010 (year prior to publication of most recent systematic review) and May 2014. This revealed an additional 23 possible citations totalling 487 publications that were considered for review. These 487 publications were then reviewed based on abstract and excluded if they were not conducted in primary schools or on primary school-aged children. This reduced the number of studies to 233. Studies were then excluded if they were not: a) randomised controlled trials; b) quasi-experimental studies or, c) cluster-controlled trials. This left 55 studies. On review of the full-text paper, another 6 studies were excluded for not meeting the inclusion criteria (i.e. conducted in a laboratory setting) or being a duplicate study. The final 49 studies were all in the form of peer -reviewed journal publications. All 49 of the included articles are presented in Table 1. Specifically, it outlines the details of the studies, including author(s), title, year, location, design and stated dominant theoretical framework, target population, and types of outcomes measured. The year of publication for included articles ranged from 1973 to 2011, with 26 studies published during or since 2004.


www.dec.nsw.gov.au

3

Question 1 (continued) Study designs and locations The final 49 studies included one randomised controlled trial, 13 quasi-experiential studies and 35 cluster controlled trials. These studies were conducted in 13 countries of which all but one (Trinidad and Tobago) are members of the Organization for Economic Co-operation and Development (OECD).

Teaching strategies and healthy eating outcomes The researchers decided that there were eight dominant teaching strategies exhibited across the 49 studies. Some studies included more than one of these teaching strategies in their intervention group. The dominant teaching strategies were: 1. curriculum approaches (i.e. nutrition education programs delivered by teachers or specialists) (n=29); 2. cross-curricular approaches (i.e. nutrition education programs that were delivered across two or more traditional primary school subjects) (n=11); 3. p arental involvement (i.e. programs requiring active participation or assistance from a parent without or outside the school environment) (n=10); 4. experiential learning approaches (i.e. school/community garden, cooking and food preparation activities) (n=10); 5. contingent reinforcement approaches (i.e. rewards or incentives given to students in response to desired behaviours) (n=7); 6. literary abstraction approaches (i.e. literature read by/ to children whereby a character promotes/exemplifies positive behaviours) (n=3); 7. g ames-based approaches (i.e. board/card games played by students at school designed to promote positive behaviour and learning of new knowledge) (n=2); and 8. web-based approaches (i.e. internet-based resources or feedback mechanisms that could be accessed by students at home or school)(n=2).

The results of the evidence review indicate that there are several dominant evidence-based approaches to teaching healthy eating in the randomised controlled trial, quasi-experimental and cluster controlled trial literature. In order to determine the strength of the evidence for these approaches, they are discussed against each of the major outcomes used to determine healthy eating and if the study achieved p-values of p.40. The decision to use an effect size of d>.40 is based on Hattie’s Zone of Desired Effects (2009)11 as these approaches have the greatest influence and represent the best investment for improving educational outcomes.

Reducing Food Consumption and Energy Intake Eleven studies reported on outcomes of food consumption and the overall energy intake of primary school-aged children. Curriculum-based approaches were the most popular (seven studies) and reported achieving statistical significance of p