Associations between BMI and home, school and route environmental exposures estimated using GPS and GIS: do we see evidence of selective daily mobility bias in children?

BACKGROUND: This study examined whether objective measures of food, physical activity and built environment exposures, in home and non-home settings, contribute to children's body weight. Further, comparing GPS and GIS measures of environmental exposures along routes to and from school, we tested for evidence of selective daily mobility bias when using GPS data. METHODS: This study is a cross-sectional analysis, using objective assessments of body weight in relation to multiple environmental exposures. Data presented are from a sample of 94 school-aged children, aged 5-11 years. Children's heights and weights were measured by trained researchers, and used to calculate BMI z-scores. Participants wore a GPS device for one full week. Environmental exposures were estimated within home and school neighbourhoods, and along GIS (modelled) and GPS (actual) routes from home to school. We directly compared associations between BMI and GIS-modelled versus GPS-derived environmental exposures. The study was conducted in Mebane and Mount Airy, North Carolina, USA, in 2011. RESULTS: In adjusted regression models, greater school walkability was associated with significantly lower mean BMI. Greater home walkability was associated with increased BMI, as was greater school access to green space. Adjusted associations between BMI and route exposure characteristics were null. The use of GPS-actual route exposures did not appear to confound associations between environmental exposures and BMI in this sample. CONCLUSIONS: This study found few associations between environmental exposures in home, school and commuting domains and body weight in children. However, walkability of the school neighbourhood may be important. Of the other significant associations observed, some were in unexpected directions. Importantly, we found no evidence of selective daily mobility bias in this sample, although our study design is in need of replication in a free-living adult sample.Funding from the British Heart Foundation, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research and the Wellcome Trust under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. This study was supported, in part, by a grant from the Robert Wood Johnson Foundation, Active Living Research.This is the final published version. It first appeared at http://www.ij-healthgeographics.com/content/14/1/8

Correlates of Sedentary Time and Physical Activity Among Preschool-Aged Children

INTRODUCTION: Few studies have examined the correlates of objectively measured amounts of sedentary time and physical activity in young children. We evaluated the demographic, biological, behavioral, social, and environmental correlates of the amount of sedentary time and moderate-to-vigorous physical activity (MVPA) as measured by accelerometry in preschool-aged children. METHODS: We obtained baseline measurements of physical activity by using an Actical accelerometer among 337 preschool-aged children (aged 2-5) of overweight or obese mothers. For children, we defined sedentary time as less than 12 counts per 15 seconds and MVPA as 715 or more counts per 15 seconds. Body mass index of the mother and child (calculated from measured height and weight) and maternal physical activity as measured by accelerometer were included as potential correlates. Mothers self-reported all other potential correlates. We used multivariable linear regression analyses to examine correlates of the amount of sedentary time and MVPA. RESULTS: Children had an average of 6.1 hours per day of sedentary time and 14.9 minutes per day of MVPA. In multivariable analysis, boys (P <.001) had fewer minutes per day of sedentary time, whereas older children (P <.001), boys (P <.001), children in high-income households (>$60,000/y [P = .005]), and children who spent more time outdoors (P = .001) had more MVPA. CONCLUSION: Both modifiable and nonmodifiable factors were correlated with preschool children's amount of MVPA, which can be helpful when designing interventions for this age group. The lack of correlates for sedentary time indicates the need for further investigation into this behavior

The keys to healthy family child care homes intervention: Study design and rationale

Obesity is a major public health problem for which early preventive interventions are needed. Large numbers of young children are enrolled in some form of child care program, making these facilities influential environments in children’s development. Family child care homes (FCCH) are a specific type of child care in which children are cared for within the provider’s own residence. FCCHs serve approximately 1.5 million children in the U.S.; however, research to date has overlooked FCCH providers and their potential to positively influence children’s health-related behaviors

Nicotine Replacement and Behavioral Therapy for Smoking Cessation in Pregnancy

This study examines whether adding nicotine replacement therapy (NRT) to cognitive behavioral therapy (CBT) for pregnant smokers increases rates of smoking cessation

What are physicians' and patients' beliefs about diet, weight, exercise, and smoking cessation counseling?

10.1016/j.ypmed.2010.07.023Preventive Medicine515440-442PVTM