The school food environment : associations with adolescent soft drink and snack consumption

Background
Because students may purchase food and drinks in and around their schools, the school food environment may be important for obesity-related eating behaviors such as soft drink and snack consumption. However, research exploring the associations between school environments and specific eating behaviors is sparse.

Methods
Associations of the availability of canteen food and drinks, the presence of food stores around schools, and individual cognitions (attitudes, norms, modeling, perceived behavioral control, and intentions) with soft drink and snack consumption were examined in a cross-sectional study (2005–2006) among 1293 adolescents aged 12–15 years. Soft drink and snack consumption and related cognitions were assessed with self-administered questionnaires. The presence of food stores and the distance to the nearest food store were calculated within a 500-meter buffer around each school. Data on the availability of soft drinks and snacks in school canteens were gathered by observation. In 2007, multilevel regression models were run to analyze associations and mediation pathways between cognitions, environmental factors, and behaviors.

Results
Adolescents' attitudes, subjective norms, parental and peer modeling, and intentions were positively associated with soft drink and snack consumption. There was an inverse association between the distance to the nearest store and the number of small food stores with soft drink consumption. These effects were mediated partly by cognitions.

Conclusions
This study provided little evidence for associations of environmental factors in the school environment with soft drink and snack consumption. Individual cognitions appeared to be stronger correlates of intake than physical school-environmental factors. Longitudinal research is needed to confirm these findings.

Family physical activity and sedentary environments and weight change in children

Objective. To examine associations between family physical activity and sedentary environment and changes in body mass index (BMI) z-scores among 10-12-year-old children over three years.
Method. Design. Longitudinal (three-year follow-up). Subjects. In total, 152 boys and 192 girls aged 10-12 years at baseline.
Measurements. Measured height and weight at baseline and follow-up (weight status, BMI z-scores); aspects of the family physical activity and sedentary environment (parental and sibling modelling, reinforcement, social support, family-related barriers, rules/restrictions, home physical environment) measured with a questionnaire completed by parents at baseline.
Results. At baseline, 29.6% of boys and 21.9% of girls were overweight or obese, and mean (standard deviation, SD) BMI z-scores were 0.44 (0.99) and 0.28 (0.89), respectively. There was a significant change in BMI z-score among girls (mean change=0.19, SD=0.55, p<0.001), but not boys. Among boys, the number of items at home able to be used for sedentary behaviour (B=0.11, p=0.037) was associated with relatively greater increases in BMI z-score. Among girls, sibling engagement in physical activity at least three times/wk (B=-0.17, p=0.010) and the number of physical activity equipment items at home (B=-0.05, p=0.018) were associated with relatively greater decreases in BMI z-score.
Conclusion. Sibling physical activity and environmental stimuli for sedentary behaviours and physical activity within the home may be important targets for prevention of weight gain during the transition from childhood to adolescence.

Parent's views of the importance of making changes in settings where children spend time to prevent obesity

Aim : To examine the kinds of changes parents would like to see in those settings where children spend time (kindergartens and schools, child care centres and after-school care facilities, and the local neighbourhood) in policies and practices that impact on children’s risk of obesity, and to establish whether parents might be willing to advocate for changes in these settings.

Materials and Methods : 175 parents from five randomly selected primary schools and five randomly selected kindergartens located in suburbs of metropolitan Melbourne completed a questionnaire in which they rated the importance of a number of potential changes to promote healthy eating and increase physical activity in their children.

Results : Parents of children in kindergarten most commonly rated changes to the eating environment as important. In contrast, parents of primary school children believed changes related to both eating and physical activity in school were important. Ninety-five per cent of parents of kindergarten children and 89% of parents of primary school children believed it was possible for parents to bring about change to provide more opportunities for their child to eat more healthily and be more physically active. One in four parents reported that they had thought about or had tried to bring about changes in their community.

Conclusions : The findings suggest that mobilising parents to take an active role in advocating for change in those settings that have the potential to shape their children’s physical activity and eating behaviours may be feasible.

Neighbourhood fast food outlets and obesity in children and adults : the CLAN study

Objective : We examined associations between density of and proximity to fast food outlets and body weight in a sample of children (137 aged 8-9 years and 243 aged 13-15 years) and their parents (322 fathers and 362 mothers).
Methods : Children's measured and parents' self-reported heights and weights were used to calculate body mass index (BMI). Locations of major fast food outlets were geocoded. Bivariate linear regression analyses examined associations between the presence of any fast food outlet within a 2 km buffer around participants' homes, fast food outlet density within the 2 km buffer, and distance to the nearest outlet and BMI. Each independent variable was also entered into separate bivariate logistic regression analyses to predict the odds of being overweight or obese.
Results : Among older children, those with at least one outlet within 2 km had lower BMI z-scores. The further that fathers lived from an outlet, the higher their BMI. Among 13-15-year-old girls and their fathers, the likelihood of overweight/obesity was reduced by 80% and 50%, respectively, if they had at least one fast food outlet within 2 km of their home. Among older girls, the likelihood of being overweight/obese was reduced by 14% with each additional outlet within 2 km. Fathers' odds of being overweight/obese increased by 13% for each additional kilometre to the nearest outlet.
Conclusions : While consumption of fast food has been shown to be associated with obesity, this study provides little support for the concept that exposure to fast food outlets in the local neighbourhood increases risk of obesity.

Do features of public open spaces vary according to neighbourhood socio-economic status?

This study examined the relations between neighbourhood socio-economic status and features of public open spaces (POS) hypothesised to influence children's physical activity. Data were from the first follow-up of the Children Living in Active Neighbourhoods (CLAN) Study, which involved 540 families of 5–6 and 10–12-year-old children in Melbourne, Australia. The Socio-Economic Index for Areas Index (SEIFA) of Relative Socio-economic Advantage/Disadvantage was used to assign a socioeconomic index score to each child's neighbourhood, based on postcode. Participant addresses were geocoded using a Geographic Information System. The Open Space 2002 spatial data set was used to identify all POS within an 800 m radius of each participant's home. The features of each of these POS (1497) were audited. Variability of POS features was examined across quintiles of neighbourhood SEIFA. Compared with POS in lower socioeconomic neighbourhoods, POS in the highest socioeconomic neighbourhoods had more amenities (e.g. picnic tables and drink fountains) and were more likely to have trees that provided shade, a water feature (e.g. pond, creek), walking and cycling paths, lighting, signage regarding dog access and signage restricting other activities. There were no differences across neighbourhoods in the number of playgrounds or the number of recreation facilities (e.g. number of sports catered for on courts and ovals, the presence of other facilities such as athletics tracks, skateboarding facility and swimming pool). This study suggests that POS in high socioeconomic neighbourhoods possess more features that are likely to promote physical activity amongst children.

Socioeconomic variations in women's diets : what is the role of perceptions of the local food environment

Objectives : To test the contribution of perceived environmental factors (food availability, accessibility and affordability) to mediating socioeconomic variations in women’s fruit, vegetable and fast food consumption.

Methods : A community sample of 1580 women from 45 neighbourhoods provided survey data on their socioeconomic position (SEP) (education and income); diet (fruit, vegetable and fast food consumption); and the perceived availability of, access to and cost of healthy food in their local area.

Results : Once perceived environmental variables were considered, the associations between SEP and diet were weak and non-significant, suggesting that socioeconomic differences in diet were almost wholly explained by perceptions of food availability, accessibility and affordability.

Conclusions : Strategies to decrease socioeconomic inequalities in diet could involve promoting inexpensive ways to increase fruit and vegetable consumption, and ensuring that people of low SEP are aware that many healthy foods are available at relatively low cost. Future research should also confirm if perceptions match objective measures of food availability, accessibility and affordability, in order to address the real and/or perceived lack of healthy options in low SEP neighbourhoods.

Environmental determinants of healthy eating : in need of theory and evidence

In order to promote healthful nutrition, insight is needed into the determinants of nutrition behaviours. Behavioural determinant research and behavioural nutrition interventions have focused mostly on individual-level motivational factors. It has been argued that the individual's socio-cultural and physical environments may be the main determinants of nutrition behaviours. However, the theoretical basis and empirical evidence for environmental determinants of nutrition behaviours are not strong. The present paper is a narrative review informed by a series of systematic reviews and recent original studies on associations between environmental factors and nutrition behaviours to provide an overview and discussion of the evidence for environmental correlates and predictors of nutrition behaviour. Although the number of studies on potential environmental determinants of nutrition behaviours has increased steeply over the last decades, they include only a few well-designed studies with validated measures and guided by sound theoretical frameworks. The preliminary evidence from the available systematic reviews indicates that socio-cultural environmental factors defining what is socially acceptable, desirable and appropriate to eat may be more important for healthful eating than physical environments that define the availability and accessibility of foods. It is concluded that there is a lack of well-designed studies on environmental determinants of healthful eating behaviours. Preliminary evidence indicates that social environmental factors may be more important than physical environmental factors for healthful eating. Better-designed studies are needed to further build evidence-based theory on environmental determinants to guide the development of interventions to promote healthful eating.

Mismatch between perceived and objective measures of physical activity environments

Objectives : This study investigated the correspondence between measures of physical activity facilities obtained through self-report and objective audits; and identified the socio-demographic, cognitive and behavioral characteristics of those who perceive their physical activity environment to be less supportive than objective measures indicate.
Methods : Self-report surveys were completed by 1540 women recruited from 45 neighborhoods in Melbourne, Australia. Women reported perceived access to physical activity facilities within 2 km from home, and also socio-demographic, cognitive and behavioral factors. Objective data on physical activity facilities within a 2 km pedestrian catchment area around women's homes were sourced.
Results : There was relatively poor agreement between measures of access to physical activity facilities obtained via self-report and objective assessment. Mismatch between perceived and objectively-assessed environments was more common amongst younger and older women, and women of low income, with low self-efficacy for physical activity, who were less active, who reported using fewer facilities and who had lived in the neighborhood for less than 2 years.
Conclusions : Future studies of environmental determinants of physical activity should consider incorporating objective indices of access to facilities, or accounting for the systematic bias that may result from relying on self-report perceptions as an indicator of the actual physical activity environment.