Casey P. Durand

A systematic review of built environment factors related to physical activity and obesity risk: implications for smart growth urban planning

Smart growth is an approach to urban planning that provides a framework for making community development decisions. Despite its growing use, it is not known whether smart growth can impact physical activity. This review utilizes existing built environment research on factors that have been used in smart growth planning to determine whether they are associated with physical activity or body mass. Searching the MEDLINE, Psycinfo and Web‐of‐Knowledge databases, 204 articles were identified for descriptive review, and 44 for a more in‐depth review of studies that evaluated four or more smart growth planning principles. Five smart growth factors (diverse housing types, mixed land use, housing density, compact development patterns and levels of open space) were associated with increased levels of physical activity, primarily walking. Associations with other forms of physical activity were less common. Results varied by gender and method of environmental assessment. Body mass was largely unaffected. This review suggests that several features of the built environment associated with smart growth planning may promote important forms of physical activity. Future smart growth community planning could focus more directly on health, and future research should explore whether combinations or a critical mass of smart growth features is associated with better population health outcomes.

Which type of sedentary behaviour intervention is more effective at reducing body mass index in children? A meta-analytic review

Sedentary behaviour is emerging as an independent risk factor for paediatric obesity. Some evidence suggests that limiting sedentary behaviour alone could be effective in reducing body mass index (BMI) in children. However, whether adding physical activity and diet‐focused components to sedentary behaviour reduction interventions could lead to an additive effect is unclear. This meta‐analysis aims to assess the overall effect size of sedentary behaviour interventions on BMI reduction and to compare whether interventions that have multiple components (sedentary behaviour, physical activity and diet) have a higher mean effect size than interventions with single (sedentary behaviour) component. Included studies (n = 25) were randomized controlled trials of children (<18 years) with intervention components aimed to reduce sedentary behaviour and measured BMI at pre‐ and post‐intervention. Effect size was calculated as the mean difference in BMI change between children in an intervention group and a control group. Results indicated that sedentary behaviour interventions had a significant effect on BMI reduction. The pooled effect sizes of multi‐component interventions (g = −0.060∼−0.089) did not differ from the single‐component interventions (g = −0.154), and neither of them had a significant effect size on its own. Future paediatric obesity interventions may consider focusing on developing strategies to decrease multiple screen‐related sedentary behaviours.

Incorporating primary and secondary prevention approaches to address childhood obesity prevention and treatment in a low-income, ethnically diverse population: study design and demographic data from the Texas Childhood Obesity Research Demonstration (TX CORD) study.

BACKGROUND There is consensus that development and evaluation of a systems-oriented approach for child obesity prevention and treatment that includes both primary and secondary prevention efforts is needed. This article describes the study design and baseline data from the Texas Childhood Obesity Research Demonstration (TX CORD) project, which addresses child obesity among low-income, ethnically diverse overweight and obese children, ages 2-12 years; a two-tiered systems-oriented approach is hypothesized to reduce BMI z-scores, compared to primary prevention alone. METHODS Our study aims are to: (1) implement and evaluate a primary obesity prevention program; (2) implement and evaluate efficacy of a 12-month family-centered secondary obesity prevention program embedded within primary prevention; and (3) quantify the incremental cost-effectiveness of the secondary prevention program. Baseline demographic and behavioral data for the primary prevention community areas are presented. RESULTS Baseline data from preschool centers, elementary schools, and clinics indicate that most demographic variables are similar between intervention and comparison communities. Most families are low income (≤

Does raising type 1 error rate improve power to detect interactions in linear regression models? A simulation study.

25,000) and Hispanic/Latino (73.3-83.8%). The majority of parents were born outside of the United States. Child obesity rates exceed national values, ranging from 19.0% in preschool to 35.2% in fifth-grade children. Most parents report that their children consume sugary beverages, have a television in the bedroom, and do not consume adequate amounts of fruits and vegetables. CONCLUSIONS Interventions to address childhood obesity are warranted in low-income, ethnically diverse communities. Integrating primary and secondary approaches is anticipated to provide sufficient exposure that will lead to significant decreases in childhood obesity.

An evidence-based conceptual framework of healthy cooking

Introduction Statistical interactions are a common component of data analysis across a broad range of scientific disciplines. However, the statistical power to detect interactions is often undesirably low. One solution is to elevate the Type 1 error rate so that important interactions are not missed in a low power situation. To date, no study has quantified the effects of this practice on power in a linear regression model. Methods A Monte Carlo simulation study was performed. A continuous dependent variable was specified, along with three types of interactions: continuous variable by continuous variable; continuous by dichotomous; and dichotomous by dichotomous. For each of the three scenarios, the interaction effect sizes, sample sizes, and Type 1 error rate were varied, resulting in a total of 240 unique simulations. Results In general, power to detect the interaction effect was either so low or so high at α = 0.05 that raising the Type 1 error rate only served to increase the probability of including a spurious interaction in the model. A small number of scenarios were identified in which an elevated Type 1 error rate may be justified. Conclusions Routinely elevating Type 1 error rate when testing interaction effects is not an advisable practice. Researchers are best served by positing interaction effects a priori and accounting for them when conducting sample size calculations.

Does community type moderate the relationship between parent perceptions of the neighborhood and physical activity in children

Eating out of the home has been positively associated with body weight, obesity, and poor diet quality. While cooking at home has declined steadily over the last several decades, the benefits of home cooking have gained attention in recent years and many healthy cooking projects have emerged around the United States. The purpose of this study was to develop an evidence-based conceptual framework of healthy cooking behavior in relation to chronic disease prevention. A systematic review of the literature was undertaken using broad search terms. Studies analyzing the impact of cooking behaviors across a range of disciplines were included. Experts in the field reviewed the resulting constructs in a small focus group. The model was developed from the extant literature on the subject with 59 studies informing 5 individual constructs (frequency, techniques and methods, minimal usage, flavoring, and ingredient additions/replacements), further defined by a series of individual behaviors. Face validity of these constructs was supported by the focus group. A validated conceptual model is a significant step toward better understanding the relationship between cooking, disease and disease prevention and may serve as a base for future assessment tools and curricula.

The Utility of Geographical Information Systems (GIS) in Systems-Oriented Obesity Intervention Projects: The Selection of Comparable Study Sites for a Quasi-Experimental Intervention Design—TX CORD

Purpose. To examine whether residing in a community designed to promote physical activity moderates the relationship between parent perceptions of the neighborhood and general physical activity or active commuting to school in their children. Design. Cross-sectional. Setting. San Bernardino County, California. Subjects. Three hundred sixty-five families (one parent and one child in grades four through eight). Eighty-five reside in a smart growth community designed to be more conducive to physical activity. Measures. Parent perceptions assessed using the Neighborhood Environment Walkability Scale (NEWS). General child physical activity was measured using accelerometers, and active commuting was self-reported by children. Analysis. Two sets of regressions were performed: one for general physical activity, and one for active commuting. Separate models were run in the two sets for each of the 14 NEWS factors, while controlling for demographics. Results. For general physical activity, walking infrastructure, lack of cul-de-sacs, and social interaction had significant main effect associations (p ≤ .05). No factors were moderated by community. The relationships between active commuting to school and perceived crime, traffic hazards, hilliness, physical barriers, cul-de-sac connectivity, aesthetics, and walking infrastructure were significant for those in the smart growth community only (p ≤ .05). Conclusions. Living in an activity-friendly environment is associated with positive relationships between parent perceptions and active commuting behaviors in children. Future interventions should account for both the perceived neighborhood environment and available physical activity infrastructure.

Efficacy of a community‐ versus primary care–centered program for childhood obesity: TX CORD RCT

BACKGROUND The Texas Childhood Obesity Research Demonstration project (TX CORD) uses a systems-oriented approach to address obesity that includes individual and family interventions, community-level action, as well as environmental and policy initiatives. Given that randomization is seldom possible in community-level intervention studies, TX CORD uses a quasi-experimental design. Comparable intervention and comparison study sites are needed to address internal validity bias. METHODS TX CORD was designed to be implemented in low-income, ethnically diverse communities in Austin and Houston, Texas. A three-stage Geographical Information System (GIS) methodology was used to establish and ascertain the comparability of the intervention and comparison study sites. Census tract (stage 1) and school (stage 2) data were used to identify spatially exclusive geographic areas that were comparable. In stage 3, study sites were compared on demographic characteristics, socioeconomic status (SES), food assets, and physical activity (PA) assets. Students t-test was used to examine significant differences between the selected sites. RESULTS The methodology that was used resulted in the selection of catchment areas with demographic and socioeconomic characteristics that fit the target population: ethnically diverse population; lower-median household income; and lower home ownership rates. Additionally, the intervention and comparison sites were statistically comparable on demographic and SES variables, as well as food assets and PA assets. CONCLUSIONS This GIS approach can provide researchers, program evaluators, and policy makers with useful tools for both research and practice. Area-level information that allows for robust understanding of communities can enhance analytical procedures in community health research and offer significant contributions in terms of community assessment and engagement.

Development and Validation of the Cognitive Behavioral Physical Activity Questionnaire.

This randomized controlled trial was conducted to determine comparative efficacy of a 12‐month community‐centered weight management program (MEND2‐5 for ages 2‐5 or MEND/CATCH6‐12 for ages 6‐12) against a primary care‐centered program (Next Steps) in low‐income children.

School-Based Obesity-Prevention Programs

Purpose. Develop and demonstrate preliminary validation of a brief questionnaire aimed at assessing social cognitive determinants of physical activity (PA) in a college population. Design. Quantitative and observational. Setting. A midsized northeastern university. Subjects. Convenience sample of 827 male and female college students age 18 to 24 years. Measures. International Physical Activity Questionnaire and a PA stage-of-change algorithm. Analysis. A sequential process of survey development, including item generation and data reduction analyses by factor analysis, was followed with the goal of creating a parsimonious questionnaire. Structural equation modeling was used for confirmatory factor analysis and construct validation was confirmed against self-reported PA and stage of change. Validation analyses were replicated in a second, independent sample of 1032 college students. Results. Fifteen items reflecting PA self-regulation, outcome expectations, and personal barriers explained 65% of the questionnaire data and explained 28.6% and 39.5% of the variance in total PA and moderate-to-vigorous–intensity PA, respectively. Scale scores were distinguishable across the stages of change. Findings were similar when the Cognitive Behavioral Physical Activity Questionnaire (CBPAQ) was tested in a similar and independent sample of college students (40%; R2 moderate-to-vigorous–intensity PA = .40; p < .001). Conclusion. The CBPAQ successfully explains and predicts PA behavior in a college population, warranting its incorporation into future studies aiming at understanding and improving on PA behavior in college students.