Gill Cowburn

A systematic review of the influence of the retail food environment around schools on obesity-related outcomes

The high prevalence of childhood obesity has led to questions about the influence of ‘obesogenic’ environments on childrens health. Public health interventions targeting the retail food environment around schools have been proposed, but it is unclear if they are evidence based. This systematic review investigates associations between food outlets near schools and childrens food purchases, consumption and body weight. We conducted a keyword search in 10 databases. Inclusion criteria required papers to be peer reviewed, to measure retailing around schools and to measure obesity‐related outcomes among schoolchildren. Thirty papers were included. This review found very little evidence for an effect of the retail food environment surrounding schools on food purchases and consumption, but some evidence of an effect on body weight. Given the general lack of evidence for association with the mediating variables of food purchases and consumption, and the observational nature of the included studies, it is possible that the effect on body weight is a result of residual confounding. Most of the included studies did not consider individual childrens journeys through the food environment, suggesting that predominant exposure measures may not account for what individual children actually experience. These findings suggest that future interventions targeting the food environment around schools need careful evaluation.

Does the availability of snack foods in supermarkets vary internationally

BackgroundCross-country differences in dietary behaviours and obesity rates have been previously reported. Consumption of energy-dense snack foods and soft drinks are implicated as contributing to weight gain, however little is known about how the availability of these items within supermarkets varies internationally. This study assessed variations in the display of snack foods and soft drinks within a sample of supermarkets across eight countries.MethodsWithin-store audits were used to evaluate and compare the availability of potato chips (crisps), chocolate, confectionery and soft drinks. Displays measured included shelf length and the proportion of checkouts and end-of-aisle displays containing these products. Audits were conducted in a convenience sample of 170 supermarkets across eight developed nations (Australia, Canada, Denmark, Netherlands, New Zealand, Sweden, United Kingdom (UK), and United States of America (US)).ResultsThe mean total aisle length of snack foods (adjusted for store size) was greatest in supermarkets from the UK (56.4 m) and lowest in New Zealand (21.7 m). When assessed by individual item, the greatest aisle length devoted to chips, chocolate and confectionery was found in UK supermarkets while the greatest aisle length dedicated to soft drinks was in Australian supermarkets. Only stores from the Netherlands (41%) had less than 70% of checkouts featuring displays of snack foods or soft drinks.ConclusionWhilst between-country variations were observed, overall results indicate high levels of snack food and soft drinks displays within supermarkets across the eight countries. Exposure to snack foods is largely unavoidable within supermarkets, increasing the likelihood of purchases and particularly those made impulsively.

Evaluating the Feasibility of Measuring Travel to School Using a Wearable Camera

Background The school journey is often studied in relation to health outcomes in children and adolescents. Self-report is the most common measurement tool. Purpose To investigate the error on self-reported journey duration in adolescents, using a wearable digital camera (Microsoft SenseCam). Methods During March–May 2011, participants (n=17; aged 13–15 years) from four schools wore wearable cameras to and from school for 1 week. The device automatically records time-stamped, first-person point-of-view images, without any action from the wearer. Participants also completed a researcher-administered self-report travel survey over the same period. Analysis took place in November 2011. Within- and between-subjects correlation coefficients and Bland-Altman 95% limits of agreement were derived, accounting for the multiple observations per individual. Results Self-report data were collected for 150 journey stages and SenseCam data for 135 (90%) of these. The within-subjects correlation coefficient for journey duration was 0.89 (95% CI=0.84, 0.93). The between-subjects correlation coefficient was 0.92 (95% CI=0.79, 0.97). The mean difference (bias) between methods at the whole sample level was small (10 seconds per journey, 95% CI= −33, 53). The wide limits of agreement (±501 seconds, 95% CI= −491, 511) reveal large random error. Conclusions Compared to direct observation from images, self-reported journey duration is accurate at the mean group level but imprecise at the level of the individual participant.

A survey of food projects in the English NHS regions and Health Action Zones in 2001

Background and Objective This article sets out the findings from an analysis of food projects, with a particular emphasis on fruit and vegetables, from the 26 Health Action Zones (HAZs) in England and those taking place within the former NHS regional areas in 2001. The objective was to gather information on the existing practice to inform future work. Methods A series of interviews with key informants in the London area and a review of all the London Health Improvement Programmes and Coronary Heart Disease Local Implementation Plans were used to inform the development of an interview schedule and questionnaire. A second phase consisted of interviews with leads in the NHS Regional Offices. The third phase involved distribution of a questionnaire to the 26 Health Action Zones (HAZs). Results Comprehensive data on food projects was not routinely available. The large number of initiatives related to food led some respondents to feel unsure as to under which policy to locate their food and fruit and vegetable work. Projects tended to be based on the development of skills (for example, cooking classes) or on a settings approach such as activities in schools or workplaces. A strategic focus was reported as being more common at a local level. Evaluation of food projects was at an early stage in many areas. Conclusions The future sustainability of food and fruit and vegetable projects was identified as a Key issue. Future policy development of food projects need to be clearly guided by a coherent policy focus and an integrated approach which clearly tackles the root causes of food access and poverty.

Assessing the options for local government to use legal approaches to combat obesity in the UK: putting theory into practice.

The law is recognized as a powerful tool to address some of the structural determinants of chronic disease, including ‘obesogenic’ environments which are a major factor in the increasing prevalence of obesity worldwide. However, it is often local – as opposed to national – government that has responsibility for an environment, including the built environment, and their role in reducing obesity using law remains relatively unexplored. With the English government shifting emphasis for improvement of public health from central to local government, this paper reviews the potential for regulatory action by local government to reduce obesity. We took a novel approach to assess the evidence and to identify legal options for implementation by local government: conducting reviews of literature, media reports and case law. Our results provide a clear rational for regulatory intervention that encourages a real choice of behaviour. They highlight strategic legal areas for reduction of obesity through restriction of traffic and promotion of active travel, promotion of access to healthy food and construction of a sustainable and active environment. Importantly, we identify current legal mechanisms for adoption by UK local government including the use of planning, licensing and transport legislation to develop local obesity prevention policy.

Exploring the opportunities for food and drink purchasing and consumption by teenagers during their journeys between home and school: a feasibility study using a novel method

OBJECTIVE To investigate the feasibility and acceptability of using wearable cameras as a method to capture the opportunities for food and drink purchasing/consumption that young people encounter on their regular journeys to and from school. DESIGN A qualitative study using multiple data-collection methods including wearable cameras, global positioning system units, individual interviews, food and drink purchase and consumption diaries completed by participants over four days, and an audit of food outlets located within an 800 m Euclidean buffer zone around each school. SETTING A community setting. SUBJECTS Twenty-two students (fourteen girls and eight boys) aged 13-15 years recruited from four secondary schools in two counties of England. RESULTS Wearable cameras offered a feasible and acceptable method for collecting food purchase and consumption data when used alongside traditional methods of data collection in a small number of teenagers. We found evidence of participants making deliberate choices about whether or not to purchase/consume food and drink on their journeys. These choices were influenced by priorities over money, friends, journey length, travel mode and ease of access to opportunities for purchase/consumption. Most food and drink items were purchased/consumed within an 800 m Euclidean buffer around school, with items commonly selected being high in energy, fat and sugar. Wearable camera images combined with interviews helped identify unreported items and misreporting errors. CONCLUSIONS Wearable camera images prompt detailed discussion and generate contextually specific information which could offer new insights and understanding around eating behaviour patterns. The feasibility of scaling up the use of these methods requires further empirical work.

Guest Commentary: Fat and other taxes, lessons for the implementation of preventive policies

Fat, sugar or sweetened beverage taxes are part of an overall public health nutrition approach to healthy eating. They are not approaches that on their own are likely to bring about change. Policy evidence from existing food tax implementation suggest that taxes need to be paralleled by subsidies and other interventions to encourage healthy eating. Such dual methods help not only contribute to nutrition outcomes but also ensure political support for food taxes. Politicians and policy makers are suspicious of taxes, using subsidies and revenue monies from taxes to support healthy eating is more likely to encourage both political and public support. Building support for policies is never just a matter of academic evidence. Public health advocates need to show more ambition by developing skills in implementing pricing policies to support healthy eating. Key opponents to taxes are the food industry who use a range of arguments to prevent taxation being implemented. Public health advocates are weak in tackling the issues of corporate power and providing evidence to maintain policy and political support. The public health movement needs to continue to develop the political will among politicians and the public for taxes on food. A new way of looking at policy formation is required and this includes addressing the power of corporate interests and the role of professionals in shaping or combating these influences.

Influence of the retail food environment around schools on obesity-related outcomes: a systematic review

Abstract Background Soaring childhood obesity rates have led to questions about the influence of obesogenic environments on childrens health. Public health interventions that target the retail food environment around schools have been proposed, but whether these interventions are evidence based is unclear. Methods We examined associations between the retail food environment near schools and food purchasing, consumption, and bodyweight of students. We catalogued and critiqued the methods and results of studies analysing these associations and sought to assess the quality of evidence within the publications. We undertook a keyword search of several databases and sources of grey literature, including Medline, Embase, Web of Science, and the Cochrane Public Health Group specialised register. Inclusion criteria required studies to be published in a peer-reviewed journal between January, 1981, and October, 2012, provide at least one measurement of food retailing surrounding schools, and include outcome data for school children aged 5–18 years. Two researchers independently reviewed papers and blindly assessed the quality of the study using a modified checklist that covered study design and reporting. Methodological heterogeneity precluded meta-analysis, so we used a semiquantitative method in which we categorised papers according to their outcomes and identified whether or not the outcome was significantly (p Findings 21 studies met our inclusion criteria. All followed a cross-sectional study design. 19 described the food environment with geographical-system-information-based measures (eg, the density or proximity of food outlets within a buffer zone around the school) and two characterised the food environment using qualitative data. Outcome measures varied considerably. Only one study examined effects on food purchasing behaviour. Far more common were studies examining effects on the consumption of fruit and vegetables and of foods high in fat, sugar, or salt, or the effects on bodyweight. The one study that examined the associations between food outlets and food purchases showed a significant correlation between the proximity of fast food outlets and the number of fast food purchases. Five papers assessed associations between food outlets around schools and the consumption of fruits and vegetables. 34 relations were assessed, half of which showed a positive correlation. Only one of these results was significant (p Interpretation This review of the scientific literature found very little evidence for an effect of the retail food environment surrounding schools on food purchases and consumption patterns, but some evidence of an effect on bodyweight. Given the general lack of evidence for association with the mediating variables of food purchasing and food consumption, and the observational nature of the studies included in this review, it is possible that this finding is a result of residual confounding. The methods for the studies varied, but many contained worrying limitations; for example, most studies measured exposure at the level of the school and only one study considered childrens actual journeys through the food environment. Better studies are required to inform effective public health policies. Funding British Heart Foundation, NHS Berkshire.

Systematic review and meta-analysis of remotely delivered interventions using self-monitoring or tailored feedback to change dietary behavior.

ABSTRACT Background Self-monitoring (SM) of diet and tailored feedback (TF) have been suggested as tools for changing dietary behavior. New technologies allow users to monitor behavior remotely, potentially improving reach, adherence, and outcomes. Objective We conducted a systematic literature review and meta-analysis to address the following question: are remotely delivered standalone (i.e., no human contact) interventions that use SM or TF effective in changing eating behaviors? Design Five databases were searched in October 2016 (updated in September 2017). Only randomized controlled trials published after 1990 were included. Trials could include any adult population with no history of disordered eating which delivered an SM or TF intervention without direct contact and recorded actual dietary consumption as an outcome. Three assessors independently screened the search results. Two reviewers extracted the study characteristics, intervention details, and outcomes, and assessed risk of bias using the Cochrane tool. Results were converted to standardized mean differences and incorporated into a 3-level (individuals and outcomes nested in studies) random effects meta-analysis. Results Twenty-six studies containing 21,262 participants were identified. The majority of the studies were judged to be unclear or at high risk of bias. The meta-analysis showed dietary improvement in the intervention group compared to the control group with a standardized mean difference of 0.17 (95% CI: 0.10, 0.24; P < 0.0001). The I2 statistic for the meta-analysis was 0.77, indicating substantial heterogeneity in results. A “one study removed” sensitivity analysis showed that no single study excessively influenced the results. Conclusions Standalone interventions containing self-regulatory methods have a small but significant effect on dietary behavior, and integrating these elements could be important in future interventions. However, there was substantial variation in study results that could not be explained by the characteristics we explored, and there were risk-of-bias concerns with the majority of studies.