Effects of changes in lunch-time competitive foods, nutrition practices, and nutrition policies on low-income middle-school children's diets

Do Food and Meal Organization Systems in Polish Primary Schools Reflect Students' Preferences and Healthy and Sustainable Dietary Guidelines? The Results of Qualitative Research for the Junior-Edu-Żywienie (JEŻ) Project

The school environment, together with that of the family, shapes students' eating behaviors, and is an important element of formal and informal nutrition education. The informal and practical dimensions can be realized through the food and meals offered/sold in school canteens, shops, and vending machines. As children and adolescents spend 6-10 h/day in schools and consume at least two meals there, the school food environment is important from a public health perspective. The aim of this study is to assess food and meal organization in primary schools in Poland. The study was conducted using individual in-depth interviews (IDIs) involving 24 school headmasters and 24 representatives of people employed in school canteens or catering companies involved in meal organization in schools. The nutritional food on offer at schools is important for shaping students' food preferences and choices, consequently influencing the development, functioning, and health of this subpopulation. The school environment can be an ideal place for hands-on nutrition education. In addition to the knowledge provided, there must be a consistent message concerning the provision of nutrition information to students between the teachings of parents, teachers, and, indirectly, the food and meals available at school. Our qualitative study is confirmed by the results of quantitative research to better understand the organization of nutrition and the problems and needs of primary schools in this area.

How to enable healthier and more sustainable food practices in collective meal contexts: A scoping review

Collective meal contexts such as restaurants, cafeterias and canteens can help accelerate transitions to healthier and more sustainable diets. However, evidence from intervention studies on these contexts lacks integration. This scoping review aimed to map determinants of dietary change in collective meal contexts across multiple settings, interventions, target groups, and target behaviors. The review provided two main outcomes: (i) identifying intervention components to promote dietary change in collective meal contexts, based on the existing body of evidence; and (ii) classifying and integrating these intervention components into an overarching framework of behavior change (i.e., COM-B system). The review encompassed twenty-eight databases via two indexing services and extracted information from 232 primary sources (27,458 records selected for title and abstract screening, 574 articles selected for full-text screening). We identified a total of 653 intervention activities, which were classified into intervention components and grouped under three broad themes, namely contextual and environmental changes, social influence, and knowledge and behavioral regulation. Multi-component interventions tended to report overall positive outcomes. The review proposes several directions for future research, including: (i) moving toward more theory-based interventions in collective meal contexts; (ii) providing more detailed information about intervention settings, implementation, target groups, activities, and materials; and (iii) improving the use of open science practices in the field. Furthermore, the review offers a free, original, open-access list and synthesis of 277 intervention studies in collective meal contexts, which can help intervention planners and evaluators optimize their efforts to promote healthier and more sustainable food practices in these contexts.

Strategies for enhancing the implementation of school-based policies or practices targeting diet, physical activity, obesity, tobacco or alcohol use

BACKGROUND

Several school-based interventions are effective in improving child diet and physical activity, and preventing excessive weight gain, and tobacco or harmful alcohol use. However, schools are frequently unsuccessful in implementing such evidence-based interventions.

OBJECTIVES

1. To evaluate the benefits and harms of strategies aiming to improve school implementation of interventions to address student diet, physical activity, tobacco or alcohol use, and obesity. 2. To evaluate the benefits and harms of strategies to improve intervention implementation on measures of student diet, physical activity, obesity, tobacco use or alcohol use; describe their cost or cost-effectiveness; and any harms of strategies on schools, school staff or students.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was between 1 September 2016 and 30 April 2021 to identify any relevant trials published since the last published review.

SELECTION CRITERIA

We defined 'Implementation' as the use of strategies to adopt and integrate evidence-based health interventions and to change practice patterns within specific settings. We included any trial (randomised controlled trial (RCT) or non-randomised controlled trial (non-RCT)) conducted at any scale, with a parallel control group that compared a strategy to implement policies or practices to address diet, physical activity, overweight or obesity, tobacco or alcohol use by students to 'no intervention', 'usual' practice or a different implementation strategy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Given the large number of outcomes reported, we selected and included the effects of a single outcome measure for each trial for the primary (implementation) and secondary (student health behaviour and obesity) outcomes using a decision hierarchy. Where possible, we calculated standardised mean differences (SMDs) to account for variable outcome measures with 95% confidence intervals (CI). For RCTs, we conducted meta-analyses of primary and secondary outcomes using a random-effects model, or in instances where there were between two and five studies, a fixed-effect model. The synthesis of the effects for non-randomised studies followed the 'Synthesis without meta-analysis' (SWiM) guidelines.

MAIN RESULTS

We included an additional 11 trials in this update bringing the total number of included studies in the review to 38. Of these, 22 were conducted in the USA. Twenty-six studies used RCT designs. Seventeen trials tested strategies to implement healthy eating, 12 physical activity and six a combination of risk factors. Just one trial sought to increase the implementation of interventions to delay initiation or reduce the consumption of alcohol. All trials used multiple implementation strategies, the most common being educational materials, educational outreach and educational meetings. The overall certainty of evidence was low and ranged from very low to moderate for secondary review outcomes. Pooled analyses of RCTs found, relative to a control, the use of implementation strategies may result in a large increase in the implementation of interventions in schools (SMD 1.04, 95% CI 0.74 to 1.34; 22 RCTs, 1917 participants; low-certainty evidence). For secondary outcomes we found, relative to control, the use of implementation strategies to support intervention implementation may result in a slight improvement on measures of student diet (SMD 0.08, 95% CI 0.02 to 0.15; 11 RCTs, 16,649 participants; low-certainty evidence) and physical activity (SMD 0.09, 95% CI -0.02 to 0.19; 9 RCTs, 16,389 participants; low-certainty evidence). The effects on obesity probably suggest little to no difference (SMD -0.02, 95% CI -0.05 to 0.02; 8 RCTs, 18,618 participants; moderate-certainty evidence). The effects on tobacco use are very uncertain (SMD -0.03, 95% CIs -0.23 to 0.18; 3 RCTs, 3635 participants; very low-certainty evidence). One RCT assessed measures of student alcohol use and found strategies to support implementation may result in a slight increase in use (odds ratio 1.10, 95% CI 0.77 to 1.56; P = 0.60; 2105 participants). Few trials reported the economic evaluations of implementation strategies, the methods of which were heterogeneous and evidence graded as very uncertain. A lack of consistent terminology describing implementation strategies was an important limitation of the review.

AUTHORS' CONCLUSIONS

The use of implementation strategies may result in large increases in implementation of interventions, and slight improvements in measures of student diet, and physical activity. Further research is required to assess the impact of implementation strategies on such behavioural- and obesity-related outcomes, including on measures of alcohol use, where the findings of one trial suggest it may slightly increase student risk. Given the low certainty of the available evidence for most measures further research is required to guide efforts to facilitate the translation of evidence into practice in this setting.

Systematic Review: Effect of Health Education Intervention on Improving Knowledge, Attitudes and Practices of Adolescents on Malnutrition

Adolescence is a phase in the life cycle of human beings. Adequate knowledge, attitudes and practices towards malnutrition are necessary for proper growth and development and for their future children. This systematic review aimed to determine the effect of health education intervention to improve the knowledge, attitudes and practices of adolescents on malnutrition. PubMed, Scopus, clinical trials, CINAHL, SAGE, Science Direct and Medline were searched according to Preferred Reporting Item for Systematic Reviews and Meat-analysis (PRISMA) guidelines to identified published studies from January 2013 to December 2019 based on the inclusion and exclusion criteria. A total of eight studies were included in this review. Data extraction was done based on randomized controlled trial only. Three out of the eight studies had low risk of bias, the overall evidence of the study was moderate. Findings from this study suggest that health education intervention among adolescents have significantly improved their knowledge, attitudes and practices. More specific interventions should be conducted in low and middle income countries since they bear more of the burden of malnutrition globally.

The Effect of Supportive Implementation of Healthier Canteen Guidelines on Changes in Dutch School Canteens and Student Purchase Behaviour

We developed an implementation plan including several components to support implementation of the "Guidelines for Healthier Canteens" in Dutch secondary schools. This study evaluated the effect of this plan on changes in the school canteen and on food and drink purchases of students. In a 6 month quasi-experimental study, ten intervention schools (IS) received support implementing the guidelines, and ten control schools (CS) received only the guidelines. Changes in the health level of the cafeteria and vending machines were assessed and described. Effects on self-reported purchase behaviour of students were analysed using mixed logistic regression analyses. IS scored higher on healthier availability in the cafeteria (77.2%) and accessibility (59.0%) compared to CS (60.1%, resp. 50.0%) after the intervention. IS also showed more changes in healthier offers in the cafeteria (range -3 to 57%, mean change 31.4%) and accessibility (range 0 to 50%, mean change 15%) compared to CS (range -9 to 46%, mean change 9.7%; range -30 to 20% mean change 7% resp.). Multi-level logistic regression analyses on the intervention/control and health level of the canteen in relation to purchase behaviour showed no relevant relations. In conclusion, the offered support resulted in healthier canteens. However, there was no direct effect on students' purchase behaviour during the intervention.

Healthier Food and Beverage Interventions in Schools: Four Community Guide Systematic Reviews

CONTEXT

Healthy eating during childhood is important for optimal growth and helps reduce the risk of obesity, which has potentially serious health consequences. Changing the school food environment may offer one way to improve students' dietary intake. This manuscript reports 4 Community Guide systematic reviews examining the effectiveness of interventions in schools promoting healthy eating and weight.

EVIDENCE ACQUISITION

School obesity prevention programs aiming to improve diet were identified from a 2013 Agency for Health Care Research and Quality systematic review and an updated search (August 2012-January 4, 2017). In 2017-2018, Community Guide systematic review methods were used to assess effectiveness as determined by dietary behavior and weight changes.

EVIDENCE SYNTHESIS

Interventions improving school meals or offering fruits and vegetables (n=27 studies) are considered effective. Evidence is insufficient to determine the effectiveness of interventions supporting healthier snack foods and beverages outside of school meal programs given inconsistent findings (n=13 studies). Multicomponent interventions to increase availability of healthier foods and beverages are considered effective. These interventions must include 1 component from school meals or fruit and vegetable programs and interventions supporting healthier snack foods and beverages (n=12 studies). There is insufficient evidence to determine the effectiveness of interventions to increase water access because only 2 studies met inclusion criteria.

CONCLUSIONS

A total of 2 school-based dietary interventions have favorable effects for improving dietary habits and modest effects for improving or maintaining weight. More evidence is needed regarding interventions with insufficient findings. These reviews may inform researchers and school administrators about healthy eating and obesity prevention interventions.

Effectiveness of Interventions to Promote Healthy Eating Habits in Children and Adolescents at Risk of Poverty: Systematic Review and Meta-Analysis

The objective of this review was to provide an up-to-date review of trials that include behavioral intervention on the eating habits of children and adolescents at risk of poverty, applying meta-analysis to estimate the size of the intervention effect. A systematic literature search was performed in the following databases: MEDLINE via Pubmed and via EBSCOhost, LILACS and IBECS via VHL. The MeSH terms were used: "social class", "poverty", "diet", "health promotion" (PROSPERO ID: 183900). A total of 14 articles were finally included in this systematic review. The primary results of the included studies were meta-analyzed with the RevMan 5.3 program, assuming a random effects model. Analysis of the overall effect showed combined standardized mean differences (SMD) of 0.16 (CI 95%: [0.03, 0.30], I² = 76%). The p-value for the Z statistic was 0.02, which reflects accuracy in the effect estimation. When establishing subgroups based on the intervention tracking time points, studies that provided longer-term follow-up data showed a combined SMD of 0.15 (CI 95%: [-0.02, 0.32], I² = 81%]). Small effects of behavioral interventions were found to promote healthy eating habits, but better effects were shown in cases where the invention was followed up in the long term.

Effectiveness of school-based health promotion interventions prioritized by stakeholders from health and education sectors: A systematic review and meta-analysis

Childhood obesity and associated modifiable risk factors exert significant burden on the health care system. The goal of this systematic review and meta-analysis was to examine the effectiveness of school-based intervention types perceived by Canadian stakeholders in health and education as feasible, acceptable and sustainable in terms of improving physical activity (PA), fruit and vegetable intake, and body weight. We searched multiple databases for studies that evaluated school-based interventions to prevent obesity and associated risk factors (i.e., unhealthy diet, physical inactivity, sedentary behaviour) in children aged 4–18 years from January 1, 2012 to January 28, 2020. From 10,871 identified records, we included 83 and 80 studies in our systematic review and meta-analysis, respectively. Comprehensive School Health (CSH) and interventions which focused on modifications to school nutrition policies showed statistically significant positive effects on fruit intake of 0.13 (95% CI: 0.04, 0.23) and 0.30 (95% CI: 0.1, 0.51) servings per day, respectively. No intervention types showed statistically significant effect on vegetable intake. CSH, modifications to physical education (PE) curriculum, and multicomponent interventions showed statistically significant difference in BMI of −0.26 (95% CI: −0.40, −0.12), −0.16 (95% CI: −0.3, −0.02), and −0.18 (95% CI: −0.29, −0.07), respectively. CSH interventions showed positive effect on step-count per day, but no other types of interventions showed significant effect on any of PA outcome measures. Thus, the results of this systematic review and meta-analysis suggest that decision-makers should carefully consider CSH, multicomponent interventions, modifications to PE curricula and school nutrition policies to prevent childhood obesity.

School Wellness Environments: Perceptions Versus Realities

The U.S. Department of Agriculture Final Rule on School Wellness Policy requires schools to self-evaluate wellness policies and environments. To understand the utility of this information, this study evaluates the validity of school-reported wellness information against directly observed data. Wellness leaders at 10 Midwestern elementary schools completed a questionnaire spanning nine school wellness settings. School-reported information was compared against a direct observation protocol. Percent agreement and κ statistics were used to assess agreement between school reporters and direct observation. Overall percent agreement between reporters and direct observation was 77.1%. Agreement ranged from 67.3% (Lunchroom Environment) to 92.0% (School Wellness Policies) across the nine categories. κ results showed that 65.7% of the items demonstrated fair or better reporter agreement. The results provide preliminary support for the utility of schools' self-reported wellness information. Facilitation of independent reporting on wellness environments by school leaders will contribute to broader applications for school wellness programming.

Evaluating the Potential Health and Revenue Outcomes of a 100% Healthy Vending Machine Nutrition Policy at a Large Agency in Los Angeles County, 2013-2015

CONTEXT

Healthy vending machine policies are viewed as a promising strategy for combating the growing obesity epidemic in the United States. Few studies have evaluated the short- and intermediate-term outcomes of healthy vending policies, especially for interventions that require 100% healthy products to be stocked.

OBJECTIVE

To evaluate the potential impact of a 100% healthy vending machine nutrition policy.

DESIGN

The vendor's quarterly revenue, product sales records, and nutritional information data from 359 unique vending machines were used to conduct a baseline and follow-up policy analysis.

SETTING

County of Los Angeles facilities, 2013-2015.

PARTICIPANTS

Vending machines in facilities located across Los Angeles County.

INTERVENTION

A healthy vending machine policy executed in 2013 that required 100% of all products sold in contracted machines meet specified nutrition standards.

OUTCOME MEASURES

Policy adherence; average number of calories, sugar, and sodium in food products sold; revenue change.

RESULTS

Policy adherence increased for snacks and beverages sold by the vending machines by 89% and 98%, respectively. Average snack and beverage revenues decreased by 37% and 34%, respectively, during the sampled period.

CONCLUSIONS

Although a 100% healthy vending policy represents a promising strategy for encouraging purchases of healthier foods, steps should be taken to counteract potential revenue changes when planning its implementation.

Environmental interventions to reduce the consumption of sugar-sweetened beverages and their effects on health

BACKGROUND

Frequent consumption of excess amounts of sugar-sweetened beverages (SSB) is a risk factor for obesity, type 2 diabetes, cardiovascular disease and dental caries. Environmental interventions, i.e. interventions that alter the physical or social environment in which individuals make beverage choices, have been advocated as a means to reduce the consumption of SSB.

OBJECTIVES

To assess the effects of environmental interventions (excluding taxation) on the consumption of sugar-sweetened beverages and sugar-sweetened milk, diet-related anthropometric measures and health outcomes, and on any reported unintended consequences or adverse outcomes.

SEARCH METHODS

We searched 11 general, specialist and regional databases from inception to 24 January 2018. We also searched trial registers, reference lists and citations, scanned websites of relevant organisations, and contacted study authors.

SELECTION CRITERIA

We included studies on interventions implemented at an environmental level, reporting effects on direct or indirect measures of SSB intake, diet-related anthropometric measures and health outcomes, or any reported adverse outcome. We included randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs), controlled before-after (CBA) and interrupted-time-series (ITS) studies, implemented in real-world settings with a combined length of intervention and follow-up of at least 12 weeks and at least 20 individuals in each of the intervention and control groups. We excluded studies in which participants were administered SSB as part of clinical trials, and multicomponent interventions which did not report SSB-specific outcome data. We excluded studies on the taxation of SSB, as these are the subject of a separate Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion, extracted data and assessed the risks of bias of included studies. We classified interventions according to the NOURISHING framework, and synthesised results narratively and conducted meta-analyses for two outcomes relating to two intervention types. We assessed our confidence in the certainty of effect estimates with the GRADE framework as very low, low, moderate or high, and presented 'Summary of findings' tables.

MAIN RESULTS

We identified 14,488 unique records, and assessed 1030 in full text for eligibility. We found 58 studies meeting our inclusion criteria, including 22 RCTs, 3 NRCTs, 14 CBA studies, and 19 ITS studies, with a total of 1,180,096 participants. The median length of follow-up was 10 months. The studies included children, teenagers and adults, and were implemented in a variety of settings, including schools, retailing and food service establishments. We judged most studies to be at high or unclear risk of bias in at least one domain, and most studies used non-randomised designs. The studies examine a broad range of interventions, and we present results for these separately.Labelling interventions (8 studies): We found moderate-certainty evidence that traffic-light labelling is associated with decreasing sales of SSBs, and low-certainty evidence that nutritional rating score labelling is associated with decreasing sales of SSBs. For menu-board calorie labelling reported effects on SSB sales varied.Nutrition standards in public institutions (16 studies): We found low-certainty evidence that reduced availability of SSBs in schools is associated with decreased SSB consumption. We found very low-certainty evidence that improved availability of drinking water in schools and school fruit programmes are associated with decreased SSB consumption. Reported associations between improved availability of drinking water in schools and student body weight varied.Economic tools (7 studies): We found moderate-certainty evidence that price increases on SSBs are associated with decreasing SSB sales. For price discounts on low-calorie beverages reported effects on SSB sales varied.Whole food supply interventions (3 studies): Reported associations between voluntary industry initiatives to improve the whole food supply and SSB sales varied.Retail and food service interventions (7 studies): We found low-certainty evidence that healthier default beverages in children's menus in chain restaurants are associated with decreasing SSB sales, and moderate-certainty evidence that in-store promotion of healthier beverages in supermarkets is associated with decreasing SSB sales. We found very low-certainty evidence that urban planning restrictions on new fast-food restaurants and restrictions on the number of stores selling SSBs in remote communities are associated with decreasing SSB sales. Reported associations between promotion of healthier beverages in vending machines and SSB intake or sales varied.Intersectoral approaches (8 studies): We found moderate-certainty evidence that government food benefit programmes with restrictions on purchasing SSBs are associated with decreased SSB intake. For unrestricted food benefit programmes reported effects varied. We found moderate-certainty evidence that multicomponent community campaigns focused on SSBs are associated with decreasing SSB sales. Reported associations between trade and investment liberalisation and SSB sales varied.Home-based interventions (7 studies): We found moderate-certainty evidence that improved availability of low-calorie beverages in the home environment is associated with decreased SSB intake, and high-certainty evidence that it is associated with decreased body weight among adolescents with overweight or obesity and a high baseline consumption of SSBs.Adverse outcomes reported by studies, which may occur in some circumstances, included negative effects on revenue, compensatory SSB consumption outside school when the availability of SSBs in schools is reduced, reduced milk intake, stakeholder discontent, and increased total energy content of grocery purchases with price discounts on low-calorie beverages, among others. The certainty of evidence on adverse outcomes was low to very low for most outcomes.We analysed interventions targeting sugar-sweetened milk separately, and found low- to moderate-certainty evidence that emoticon labelling and small prizes for the selection of healthier beverages in elementary school cafeterias are associated with decreased consumption of sugar-sweetened milk. We found low-certainty evidence that improved placement of plain milk in school cafeterias is not associated with decreasing sugar-sweetened milk consumption.

AUTHORS' CONCLUSIONS

The evidence included in this review indicates that effective, scalable interventions addressing SSB consumption at a population level exist. Implementation should be accompanied by high-quality evaluations using appropriate study designs, with a particular focus on the long-term effects of approaches suitable for large-scale implementation.

Copycat snacks: Can students differentiate between school and store snacks?

In 2014, the national Smart Snacks in School nutrition standards placed regulations on all snack foods sold in schools. Many food companies reformulated common snack food products for sale in schools, called "copycat snacks", which look similar to nutritionally different foods sold in stores. It is possible that these snacks create consumer confusion among students. The purpose of this study was to determine if middle school students could differentiate, in taste and appearance, between school (copycat) and store versions of common snacks. Seventy-six middle school students evaluated three different food products offered in schools: Froot Loops, Rice Krispy Treats, and Doritos. Students tasted snacks in a series of triangle tests for difference, one for each snack food, including school and store versions. Students were also presented with packages, school and store versions of the same products, and asked to determine the expected taste, purchase intentions, and perceived healthfulness. Students could determine taste differences between school and store Rice Krispy Treats yet could not differentiate between Froot Loop and Dorito varieties. Students rated store versions of all three snacks with greater expected taste, higher intention to purchase, and as less healthy. While it seems product confusion concerning copycat snacks may not be severe in this sample, snack food brands are still a prominent feature in schools. It is possible that these copycat snacks can confuse students' perceptions of healthy foods. Alternative packaging for school foods or reformation of store versions of snack foods may be viable solutions to this problem.

Strategies for enhancing the implementation of school-based policies or practices targeting risk factors for chronic disease

BACKGROUND

A number of school-based policies or practices have been found to be effective in improving child diet and physical activity, and preventing excessive weight gain, tobacco or harmful alcohol use. Schools, however, frequently fail to implement such evidence-based interventions.

OBJECTIVES

The primary aims of the review are to examine the effectiveness of strategies aiming to improve the implementation of school-based policies, programs or practices to address child diet, physical activity, obesity, tobacco or alcohol use.Secondary objectives of the review are to: Examine the effectiveness of implementation strategies on health behaviour (e.g. fruit and vegetable consumption) and anthropometric outcomes (e.g. BMI, weight); describe the impact of such strategies on the knowledge, skills or attitudes of school staff involved in implementing health-promoting policies, programs or practices; describe the cost or cost-effectiveness of such strategies; and describe any unintended adverse effects of strategies on schools, school staff or children.

SEARCH METHODS

All electronic databases were searched on 16 July 2017 for studies published up to 31 August 2016. We searched the following electronic databases: Cochrane Library including the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; MEDLINE In-Process & Other Non-Indexed Citations; Embase Classic and Embase; PsycINFO; Education Resource Information Center (ERIC); Cumulative Index to Nursing and Allied Health Literature (CINAHL); Dissertations and Theses; and SCOPUS. We screened reference lists of all included trials for citations of other potentially relevant trials. We handsearched all publications between 2011 and 2016 in two specialty journals (Implementation Science and Journal of Translational Behavioral Medicine) and conducted searches of the WHO International Clinical Trials Registry Platform (ICTRP) (http://apps.who.int/trialsearch/) as well as the US National Institutes of Health registry (https://clinicaltrials.gov). We consulted with experts in the field to identify other relevant research.

SELECTION CRITERIA

'Implementation' was defined as the use of strategies to adopt and integrate evidence-based health interventions and to change practice patterns within specific settings. We included any trial (randomised or non-randomised) conducted at any scale, with a parallel control group that compared a strategy to implement policies or practices to address diet, physical activity, overweight or obesity, tobacco or alcohol use by school staff to 'no intervention', 'usual' practice or a different implementation strategy.

DATA COLLECTION AND ANALYSIS

Citation screening, data extraction and assessment of risk of bias was performed by review authors in pairs. Disagreements between review authors were resolved via consensus, or if required, by a third author. Considerable trial heterogeneity precluded meta-analysis. We narratively synthesised trial findings by describing the effect size of the primary outcome measure for policy or practice implementation (or the median of such measures where a single primary outcome was not stated).

MAIN RESULTS

We included 27 trials, 18 of which were conducted in the USA. Nineteen studies employed randomised controlled trial (RCT) designs. Fifteen trials tested strategies to implement healthy eating policies, practice or programs; six trials tested strategies targeting physical activity policies or practices; and three trials targeted tobacco policies or practices. Three trials targeted a combination of risk factors. None of the included trials sought to increase the implementation of interventions to delay initiation or reduce the consumption of alcohol. All trials examined multi-strategic implementation strategies and no two trials examined the same combinations of implementation strategies. The most common implementation strategies included educational materials, educational outreach and educational meetings. For all outcomes, the overall quality of evidence was very low and the risk of bias was high for the majority of trials for detection and performance bias.Among 13 trials reporting dichotomous implementation outcomes-the proportion of schools or school staff (e.g. classes) implementing a targeted policy or practice-the median unadjusted (improvement) effect sizes ranged from 8.5% to 66.6%. Of seven trials reporting the percentage of a practice, program or policy that had been implemented, the median unadjusted effect (improvement), relative to the control ranged from -8% to 43%. The effect, relative to control, reported in two trials assessing the impact of implementation strategies on the time per week teachers spent delivering targeted policies or practices ranged from 26.6 to 54.9 minutes per week. Among trials reporting other continuous implementation outcomes, findings were mixed. Four trials were conducted of strategies that sought to achieve implementation 'at scale', that is, across samples of at least 50 schools, of which improvements in implementation were reported in three trials.The impact of interventions on student health behaviour or weight status were mixed. Three of the eight trials with physical activity outcomes reported no significant improvements. Two trials reported reductions in tobacco use among intervention relative to control. Seven of nine trials reported no between-group differences on student overweight, obesity or adiposity. Positive improvements in child dietary intake were generally reported among trials reporting these outcomes. Three trials assessed the impact of implementation strategies on the attitudes of school staff and found mixed effects. Two trials specified in the study methods an assessment of potential unintended adverse effects, of which, they reported none. One trial reported implementation support did not significantly increase school revenue or expenses and another, conducted a formal economic evaluation, reporting the intervention to be cost-effective. Trial heterogeneity, and the lack of consistent terminology describing implementation strategies, were important limitations of the review.

AUTHORS' CONCLUSIONS

Given the very low quality of the available evidence, it is uncertain whether the strategies tested improve implementation of the targeted school-based policies or practices, student health behaviours, or the knowledge or attitudes of school staff. It is also uncertain if strategies to improve implementation are cost-effective or if they result in unintended adverse consequences. Further research is required to guide efforts to facilitate the translation of evidence into practice in this setting.

Measures of the food environment: A systematic review of the field, 2007-2015

BACKGROUND

Many studies have examined the relationship between the food environment and health-related outcomes, but fewer consider the integrity of measures used to assess the food environment. The present review builds on and makes comparisons with a previous review examining food environment measures and expands the previous review to include a more in depth examination of reliability and validity of measures and study designs employed.

METHODS

We conducted a systematic review of studies measuring the food environment published between 2007 and 2015. We identified these articles through: PubMed, Embase, Web of Science, PsycINFO, and Global Health databases; tables of contents of relevant journals; and the National Cancer Institute's Measures of the Food Environment website. This search yielded 11,928 citations. We retained and abstracted data from 432 studies.

RESULTS

The most common methodology used to study the food environment was geographic analysis (65% of articles) and the domination of this methodology has persisted since the last review. Only 25.9% of studies in this review reported the reliability of measures and 28.2% reported validity, but this was an improvement as compared to the earlier review. Very few of the studies reported construct validity. Studies reporting measures of the school or worksite environment have decreased since the previous review. Only 13.9% of the studies used a longitudinal design.

CONCLUSIONS

To strengthen research examining the relationship between the food environment and population health, there is a need for robust and psychometrically-sound measures and more sophisticated study designs.

The School Food Environment and Obesity Prevention: Progress Over the Last Decade

The school food environment-including when and where children obtain food and the types of options available during the school day-plays an important role in children's consumption patterns. Thus, childhood obesity prevention efforts often focus on altering the school food environment as a mechanism for improving student dietary intake. This review examines the role school food programs and policies play in improving children's diet, weight, and health. Overall, research suggests that significant improvements have been made in school nutrition policies and programs. Due to the recent program changes made as a result of the 2010 Healthy, Hunger-Free Kids Act, an emphasis was placed on research conducted over the past decade and especially on the evaluation of foods and beverages served and sold since implementation of this national law. This review also examines remaining gaps in the literature and opportunities for further improvements in school food programs and policies.

Smart food policies for obesity prevention

Prevention of obesity requires policies that work. In this Series paper, we propose a new way to understand how food policies could be made to work more effectively for obesity prevention. Our approach draws on evidence from a range of disciplines (psychology, economics, and public health nutrition) to develop a theory of change to understand how food policies work. We focus on one of the key determinants of obesity: diet. The evidence we review suggests that the interaction between human food preferences and the environment in which those preferences are learned, expressed, and reassessed has a central role. We identify four mechanisms through which food policies can affect diet: providing an enabling environment for learning of healthy preferences, overcoming barriers to the expression of healthy preferences, encouraging people to reassess existing unhealthy preferences at the point-of-purchase, and stimulating a food-systems response. We explore how actions in three specific policy areas (school settings, economic instruments, and nutrition labelling) work through these mechanisms, and draw implications for more effective policy design. We find that effective food-policy actions are those that lead to positive changes to food, social, and information environments and the systems that underpin them. Effective food-policy actions are tailored to the preference, behavioural, socioeconomic, and demographic characteristics of the people they seek to support, are designed to work through the mechanisms through which they have greatest effect, and are implemented as part of a combination of mutually reinforcing actions. Moving forward, priorities should include comprehensive policy actions that create an enabling environment for infants and children to learn healthy food preferences and targeted actions that enable disadvantaged populations to overcome barriers to meeting healthy preferences. Policy assessments should be carefully designed on the basis of a theory of change, using indicators of progress along the various pathways towards the long-term goal of reducing obesity rates.

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.

The Michigan Healthy School Action Tools process generates improvements in school nutrition policies and practices, and student dietary intake

The Michigan Healthy School Action Tools (HSAT) is an online self-assessment and action planning process for schools seeking to improve their health policies and practices. The School Nutrition Advances Kids study, a 2-year quasi-experimental intervention with low-income middle schools, evaluated whether completing the HSAT with a facilitator assistance and small grant funding resulted in (1) improvements in school nutrition practices and policies and (2) improvements in student dietary intake. A total of 65 low-income Michigan middle schools participated in the study. The Block Youth Food Frequency Questionnaire was completed by 1,176 seventh-grade students at baseline and in eighth grade (during intervention). Schools reported nutrition-related policies and practices/education using the School Environment and Policy Survey. Schools completing the HSAT were compared to schools that did not complete the HSAT with regard to number of policy and practice changes and student dietary intake. Schools that completed the HSAT made significantly more nutrition practice/education changes than schools that did not complete the HSAT, and students in those schools made dietary improvements in fruit, fiber, and cholesterol intake. The Michigan HSAT process is an effective strategy to initiate improvements in nutrition policies and practices within schools, and to improve student dietary intake.