Associations of home and neighborhood environments with children's physical activity in the U.S.-based Neighborhood Impact on Kids (NIK) longitudinal cohort study.

INTRODUCTION: Physical activity is important for children's health and well-being. Supportiveness for physical activity of home and neighborhood environments may affect children's PA, but most studies are cross-sectional. We examined environmental predictors of change in children's physical activity over two years. METHODS: Data were from the longitudinal, observational cohort study, 'Neighborhood Impact on Kids'. Participants were children (initially aged 6-12 years) and their parent/caregiver (n = 727 dyads) living in neighborhoods throughout San Diego County, California and King County (Seattle area), Washington, USA. Children's moderate-to-vigorous physical activity (MVPA) was measured using accelerometers at T1 (Time 1 or baseline, 2007-2009) and T2, the two-year follow-up. At T1, parents survey-reported on physical activity (PA) equipment at home and demographics. Neighborhood environment was measured using spatial data in Geographic Information Systems (intersection density; park availability) and in-person audits (informal play space near home; park-based PA facilities; land use; support for walking/cycling). Generalized additive mixed models estimated total effects, then direct effects, of environmental attributes on MVPA at T1. Two-way moderating effects of child's sex and age were examined at T1. To examine associations of environmental exposures with changes in MVPA, we estimated interaction effects of environmental attributes on the association between time and MVPA. RESULTS: On average, children accumulated 146 min/day (standard deviation or SD = 53) of MVPA at T1, and 113 (SD = 58) min/day at T2. There were no significant total or direct effects of environmental attributes on MVPA at T1, and no significant two-way interaction effects of child's age and sex for T1 MVPA. Having informal play spaces proximal to home with more amenities was associated with less MVPA decline from T1 to T2. Higher residential density, higher land use mix, and higher number of PA facilities in nearby parks were unexpectedly associated with greater MVPA decline. CONCLUSION: Higher quality informal play spaces close to home may help offset declines in MVPA during middle childhood, as they may promote unstructured active play with opportunities for parental or neighbor surveillance. Unexpectedly, environmental factors consistent with higher walkability were associated with greater declines in children's MVPA. As physical activity differs across the lifespan, so may environmental factors that facilitate it.

Navigating Health Equity Through Mobility Justice: Youth of Color Organizing for Transportation Equity in Our Backyards.

There is growing awareness that the built environment and transportation affect many aspects of individual and community well-being and health. Built environment and transportation planning and decision-making, however, rarely integrate robust engagement and input from youth, particularly racially/ethnically and economically diverse youth, despite the likelihood that such planning and decisions will affect their futures. Strategies are needed that prepare, engage, and ultimately empower youth in changing systems, processes, and programs that promote equitable mobility access and opportunity for youth now and in these futures. This article describes the development, implementation, actions, and impact of the Youth for Equitable Streets (YES) Fellowship program, through the perspective of the program participants, including the youth (the Fellows), program manager, and program evaluator, focusing on key factors for making this work youth-centered and oriented to successfully influence social change in transportation for mobility justice.

Design and rationale for the supermarket and web-based intervention targeting nutrition (SuperWIN) for cardiovascular risk reduction trial.

PURPOSE: The prevalence of chronic diseases is increasing largely due to suboptimal dietary habits. It is not known whether individualized, supermarket-based, nutrition education delivered by registered dietitians, utilizing the advantages of the in-store and online environments, and electronically collected purchasing data, can increase dietary quality. METHODS AND RESULTS: The supermarket and web-based intervention targeting nutrition (SuperWIN) for cardiovascular risk reduction trial is a randomized, controlled dietary intervention study. Adults identified from a primary care network with 1 or more risk factors were randomized at their preferred store to: (1) standard of care plus individualized, point- of-purchase nutrition education; (2) standard of care plus individualized, point- of-purchase nutrition education enhanced with online shopping technologies and training; or (3) standard of care alone. Educational sessions within each store's clinic and aisles, emphasized the dietary approaches to stop hypertension (DASH) diet. The primary assessment was an intention-to-treat comparison on the effects of the dietary interventions on mean change in DASH score (90-point range) from baseline to 3 months (post-intervention). Additional outcomes included blood pressure, lipids, weight, purchasing behavior, food literacy, and intervention feedback. Between April 2019 to February 2021, 267 participants were randomized (20 excluded due to coronavirus disease pandemic). Median age was 58 years, 69% were female, 64% had a college degree, 53% worked full-time, 64% were obese, 73% were treated with blood pressure and 42% with cholesterol medications, and most had low-to-moderate diet quality. CONCLUSION: The SuperWIN trial was designed to provide a rigorous evaluation of the efficacy of 2 novel, comprehensive, supermarket-based dietary intervention programs.

Location-specific psychosocial and environmental correlates of physical activity and sedentary time in young adolescents: preliminary evidence for location-specific approaches from a cross-sectional observational study.

BACKGROUND: A better understanding of the extent to which psychosocial and environmental correlates of physical activity are specific to locations would inform intervention optimization. PURPOSE: To investigate cross-sectional associations of location-general and location-specific variables with physical activity and sedentary time in three common locations adolescents spend time. METHODS: Adolescents (N = 472,Mage = 14.1,SD = 1.5) wore an accelerometer and global positioning systems (GPS) tracker and self-reported on psychosocial (e.g., self-efficacy) and environmental (e.g., equipment) factors relevant to physical activity and sedentary time. We categorized each survey item based on whether it was specific to a location to generate psychosocial and environmental indices that were location-general or specific to either school, non-school, or home location. Physical activity (MVPA) and sedentary time were based on time/location match to home, school, or all "other" locations. Mixed-effects models investigated the relation of each index with location-specific activity. RESULTS: The location-general and non-school physical activity psychosocial indices were related to greater MVPA at school and "other" locations. The school physical activity environment index was related to greater MVPA and less sedentary time at school. The home activity environment index was related to greater MVPA at home. The non-school sedentary psychosocial index was related to less sedentary time at home. Interactions among indices revealed adolescents with low support on one index benefited (i.e., exhibited more optimal behavior) from high support on another index (e.g., higher scores on the location-general PA psychosocial index moderated lower scores on the home PA environment index). Concurrent high support on two indices did not provide additional benefit. CONCLUSIONS: No psychosocial or environment indices, including location-general indices, were related to activity in all locations. Most of the location-specific indices were associated with activity in the matching location(s). These findings provide preliminary evidence that psychosocial and environmental correlates of activity are location specific. Future studies should further develop location-specific measures and evaluate these constructs and whether interventions may be optimized by targeting location-specific psychosocial and environmental variables across multiple locations.

The Availability and Price of Healthy Food in Seattle by Neighborhood Sociodemographic Characteristics.

INTRODUCTION: Unequal access to healthy food in the local food retail environment contributes to diet quality disparities. We assessed whether in-store availability and prices of healthy foods differ by neighborhood-level income and racial and ethnic composition in a representative sample of food stores in Seattle, Washington. METHODS: We developed and validated an in-store survey tool and surveyed 134 stores. We measured availability and prices of 19 items. For each store, we calculated a healthy food availability score (range, 0-25), and mean prices within each category. Using census tract data, we identified the median household income and proportions of Black and Hispanic residents for each store's neighborhood and grouped them by tertiles of these neighborhood characteristics across Seattle census tracts. We used Wald tests to compare mean availability scores and prices between tertiles and applied postestimation weights to reflect store-type distributions within each tertile. RESULTS: Neighborhoods with lower income and a larger proportion of Black residents had lower healthy food availability scores compared with neighborhoods with higher income (8.06 [95% CI, 7.04-9.07] vs 12.40 [95% CI, 10.63-14.17], P < .001) and fewer Black residents (8.88 [95% CI, 7.79-9.98] vs 12.32 [95% CI, 10.51-14.14], P = .003). Availability did not differ by Hispanic population proportions. Mean prices of grains, eggs, and meat were lower in neighborhoods with larger proportions of Black residents. CONCLUSION: We found systematic differences in healthy food availability based on neighborhood-level income and racial composition. In-store assessments of the food retail environment can inform local, tailored strategies to improve healthy food access.

General and Eating Disorder Psychopathology in Relation to Short- and Long-Term Weight Change in Treatment-Seeking Children: A Latent Profile Analysis.

BACKGROUND: Concurrent general psychopathology (GP) and eating disorder psychopathology (EDP) are commonly reported among youth with overweight/obesity and may impact weight change. PURPOSE: We identified patterns of GP and EDP in children with overweight/obesity and examined the impact on weight change following family-based behavioral obesity treatment (FBT) and maintenance interventions. METHODS: Children (N = 172) participated in 4 month FBT and subsequent 8 month weight maintenance interventions. GP and EDP were assessed prior to FBT (baseline). Child percentage overweight was assessed at baseline, post-FBT (4 months), and post-maintenance (12 months). Latent profile analysis identified patterns of baseline GP and EDP. Linear mixed-effects models examined if profiles predicted 4- and 12-month change in percentage overweight and if there were two-way and three-way interactions among these variables, adjusting for relevant covariates. RESULTS: Results indicated a three-profile structure: lower GP and EDP (LOWER); subclinically elevated GP and EDP without loss of control (LOC; HIGHER); and subclinically elevated GP and EDP with LOC (HIGHER + LOC). Across profiles, children on average achieved clinically meaningful weight loss (i.e., ≥9 unit change in percentage overweight) from baseline to 4 month FBT and sustained these improvements at 12 month maintenance. There was no evidence that latent profiles were related to percentage overweight change from baseline to FBT (p > .05) or baseline to maintenance (p > .05). There was no evidence for two-way or three-way interactions (p > .05). CONCLUSION: Concurrent GP and EDP do not portend differential short- or long-term weight change following FBT and maintenance. Future research is warranted on the durability of weight change among youth with GP and EDP. TRIAL REGISTRATION: NCT00759746.

When physical activity meets the physical environment: precision health insights from the intersection.

BACKGROUND: The physical environment can facilitate or hinder physical activity. A challenge in promoting physical activity is ensuring that the physical environment is supportive and that these supports are appropriately tailored to the individual or group in question. Ideally, aspects of the environment that impact physical activity would be enhanced, but environmental changes take time, and identifying ways to provide more precision to physical activity recommendations might be helpful for specific individuals or groups. Therefore, moving beyond a "one size fits all" to a precision-based approach is critical. MAIN BODY: To this end, we considered 4 critical aspects of the physical environment that influence physical activity (walkability, green space, traffic-related air pollution, and heat) and how these aspects could enhance our ability to precisely guide physical activity. Strategies to increase physical activity could include optimizing design of the built environment or mitigating of some of the environmental impediments to activity through personalized or population-wide interventions. CONCLUSIONS: Although at present non-personalized approaches may be more widespread than those tailored to one person's physical environment, targeting intrinsic personal elements (e.g., medical conditions, sex, age, socioeconomic status) has interesting potential to enhance the likelihood and ability of individuals to participate in physical activity.

Child neurobiology impacts success in family-based behavioral treatment for children with obesity.

BACKGROUND AND OBJECTIVES: Family-based behavioral treatment (FBT) is the recommended treatment for children with common obesity. However, there is a large variability in short- and long-term treatment response, and mechanisms for unsuccessful treatment outcomes are not fully understood. In this study, we tested if brain response to visual food cues among children with obesity before treatment predicted weight or behavioral outcomes during a 6-month behavioral weight management program and/or long-term relative weight maintenance over a 1-year follow-up period. SUBJECTS AND METHODS: Thirty-seven children with obesity (age 9-11 years, 62% male) who entered active FBT (attended two or more sessions) and had outcome data. Brain activation was assessed at pretreatment by functional magnetic resonance imaging across an a priori set of appetite-processing brain regions that included the ventral and dorsal striatum, mOFC, amygdala, substantia nigra/ventral tegmental area, and insula in response to viewing food images before and after a standardized meal. RESULTS: Children with more robust reductions in brain activation to high-calorie food cue images following a meal had greater declines in BMI z-score during FBT (r = 0.42; 95% CI: 0.09, 0.66; P = 0.02) and greater improvements in Healthy Eating Index scores (r = -0.41; 95% CI: -0.67, -0.06; P = 0.02). In whole-brain analyses, greater activation in the ventromedial prefrontal cortex, specifically by high-calorie food cues, was predictive of better treatment outcomes (whole-brain cluster corrected P = 0.02). There were no significant predictors of relative weight maintenance, and initial behavioral or hormonal measures did not predict FBT outcomes. CONCLUSIONS: Children's brain responses to a meal prior to obesity treatment were related to treatment-based weight outcomes, suggesting that neurophysiologic factors and appetitive drive, more so than initial hormone status or behavioral characteristics, limit intervention success.

Differences in adolescent activity and dietary behaviors across home, school, and other locations warrant location-specific intervention approaches.

BACKGROUND: Investigation of physical activity and dietary behaviors across locations can inform "setting-specific" health behavior interventions and improve understanding of contextual vulnerabilities to poor health. This study examined how physical activity, sedentary time, and dietary behaviors differed across home, school, and other locations in young adolescents. METHODS: Participants were adolescents aged 12-16 years from the Baltimore-Washington, DC and the Seattle areas from a larger cross-sectional study. Participants (n = 472) wore an accelerometer and Global Positioning Systems (GPS) tracker (Mean days = 5.12, SD = 1.62) to collect location-based physical activity and sedentary data. Participants (n = 789) completed 24-h dietary recalls to assess dietary behaviors and eating locations. Spatial analyses were performed to classify daily physical activity, sedentary time patterns, and dietary behaviors by location, categorized as home, school, and "other" locations. RESULTS: Adolescents were least physically active at home (2.5 min/hour of wear time) and school (2.9 min/hour of wear time) compared to "other" locations (5.9 min/hour of wear time). Participants spent a slightly greater proportion of wear time in sedentary time when at school (41 min/hour of wear time) than at home (39 min/hour of wear time), and time in bouts lasting ≥30 min (10 min/hour of wear time) and mean sedentary bout duration (5 min) were highest at school. About 61% of daily energy intake occurred at home, 25% at school, and 14% at "other" locations. Proportionately to energy intake, daily added sugar intake (5 g/100 kcal), fruits and vegetables (0.16 servings/100 kcal), high calorie beverages (0.09 beverages/100 kcal), whole grains (0.04 servings/100 kcal), grams of fiber (0.65 g/100 kcal), and calories of fat (33 kcal/100 kcal) and saturated fat (12 kcal/100 kcal) consumed were nutritionally least favorable at "other" locations. Daily sweet and savory snacks consumed was highest at school (0.14 snacks/100 kcal). CONCLUSIONS: Adolescents' health behaviors differed based on the location/environment they were in. Although dietary behaviors were generally more favorable in the home and school locations, physical activity was generally low and sedentary time was higher in these locations. Health behavior interventions that address the multiple locations in which adolescents spend time and use location-specific behavior change strategies should be explored to optimize health behaviors in each location.

Perceptions of the possible health and economic impacts of Seattle's sugary beverage tax.

BACKGROUND: Taxes on sugary beverages are an emerging strategy to improve health by reducing consumption and raising revenues to support community wellbeing. However, taxes may have unintended consequences, and perceptions of these consequences may affect attitudes towards this policy. METHODS: In June 2017, the Seattle City Council passed an ordinance imposing a tax on sugary beverages, effective January 1, 2018. Between October and December 2017, we recruited 851 adults in Seattle to complete a survey (telephone or online) about support for the tax and their perceptions of tax-related health and economic impacts. We first analyzed data for the full sample. We then tested for differences in participants' responses by household income level (< 260% Federal Poverty Level [FPL], ≥ 260% FPL) and across race/ethnicities using chi-square tests. Analyses used population weights and adjusted for multiple comparisons, using the Holm-Bonferroni Sequential Correction (p < 0.01). RESULTS: A majority of participants supported the sugary beverage tax (59%; 95% Confidence Interval [CI]: 55, 63%) and believed that the tax would improve public health (56%; CI: 52, 60%). Most participants believed that the tax would not negatively affect small businesses (52%; CI: 48, 56%) nor result in job loss (66%; CI: 62, 70%). Most participants also perceived that the tax would not negatively impact their own finances (79%; CI: 75, 82%). However, fewer lower-income (48%; CI: 42, 53%), versus higher-income participants (61%; CI: 55, 66%), perceived that the tax would improve public health, would not result in job loss (lower-income: 58%; CI: 53, 64%; higher-income: 71%; CI: 66, 75%) and would not negatively affect their own finances (lower-income: 68%; CI: 62, 73%; higher-income: 85%; CI: 81, 88%). Compared to non-Hispanic Whites, (82%; CI: 79, 86%), a smaller proportion of non-Hispanic Blacks (63%; 95% CI: 48, 75%), and Hispanics (67%; 95% CI: 51, 79%), perceived that the tax would have negative consequences for their own family finances. CONCLUSIONS: A majority of respondents supported the sugary beverage tax in Seattle. Lower-income participants were more concerned about potential financial consequences. Further evaluation of the extent to which unintended consequences occur is needed.

The Health and economic effects of light rail lines: design, methods, and protocol for a natural experiment.

BACKGROUND: The health impacts of community design have been studied extensively over the past two decades. In particular, public transportation use is associated with more walking between transit stops and shops, work, home and other destinations. Change in transit access has been linked with physical activity and obesity but seldom to health outcomes and associated costs, especially within a causal framework. Health related fiscal impacts of transit investment should be a key consideration in major transit investment decisions. METHODS: The Rails & Health study is a natural experiment evaluating changes in clinical measures, health care utilization and health care costs among Kaiser Permanente Northwest (KPNW) members following the opening of a new light rail transit (LRT) line in Portland, Oregon. The study is prospectively following 3036 adults exposed to the new LRT line and a similar cohort of 4386 adults who do not live close to the new line. Individual-level outcomes and covariates are extracted from the electronic medical record at KPNW, including member demographics and comorbidities, blood pressure, body mass index, lipids, glycosylated hemoglobin, and health care utilization and costs. In addition, participants are surveyed about additional demographics, travel patterns, physical activity (PA), and perceived neighborhood walkability. In a subsample of the study population, we are collecting direct measures of travel-related behavior-physical activity (accelerometry), global positioning system (GPS) tracking, and travel diaries-to document mechanisms responsible for observed changes in health outcomes and cost. Comprehensive measures of the built environment at baseline and after rail construction are also collected. Statistical analyses will (1) examine the effects of opening a new LRT line on chronic disease indicators, health care utilization, and health care costs and (2) evaluate the degree to which observed effects of the LRT line on health measures and costs are mediated by changes in total and transportation-associated PA. DISCUSSION: The results of the Rails & Health study will provide urban planners, transportation engineers, health practitioners, developers, and decision makers with critical information needed to document how transit investments impact population health and related costs.

Neighborhood built environment and socioeconomic status in relation to physical activity, sedentary behavior, and weight status of adolescents.

INTRODUCTION: The study examined the association of neighborhood walkability to multiple activity-related outcomes and BMI among adolescents and evaluated socioeconomic status as an effect modifier. METHOD: Cross-sectional study, with adolescents recruited from neighborhoods that met criteria for a 2 × 2 matrix defined by high/low GIS-defined walkability and high/low median income. Adolescents aged 12-16 years (n = 928) were recruited from selected neighborhoods in Maryland and King County, Washington regions in 2009-2011. There were 50.4% girls, and 66.3% were non-Hispanic white, with no medical restrictions on physical activity (PA) or diets. Total PA and sedentary time was assessed by 7 days of accelerometer monitoring. Adolescents self-reported active transport, time spent on 6 sedentary behaviors, and height and weight, used to compute BMI percentiles. Mixed model linear and logistic regressions examined outcomes for association with walkability and income, adjusting for demographic covariates and clustering within block groups. RESULTS: Walkability was positively and significantly related to objectively-measured PA (p < .001) and more frequent walking for transportation (p < .001). Total self-reported sedentary time (p = .048) and TV time (p < .007) were negatively related to walkability. Time in vehicles was negatively related to walkability only among higher-income adolescents. CONCLUSIONS: Neighborhood walkability was strongly and consistently associated with adolescents' objectively-assessed total physical activity and reported active transportation. A novel finding was that adolescents living in walkable neighborhoods reported less television time and less time in vehicles. Most results were similar across income categories. Results strengthen the rationale for recommendations to improve walkability.

The Association Between Park Facilities and Duration of Physical Activity During Active Park Visits.

Public parks provide places for urban residents to obtain physical activity (PA), which is associated with numerous health benefits. Adding facilities to existing parks could be a cost-effective approach to increase the duration of PA that occurs during park visits. Using objectively measured PA and comprehensively measured park visit data among an urban community-dwelling sample of adults, we tested the association between the variety of park facilities that directly support PA and the duration of PA during park visits where any PA occurred. Cross-classified multilevel models were used to account for the clustering of park visits (n = 1553) within individuals (n = 372) and parks (n = 233). Each additional different PA facility at a park was independently associated with a 6.8% longer duration of PA bouts that included light-intensity activity, and an 8.7% longer duration of moderate to vigorous PA time. Findings from this study are consistent with the hypothesis that more PA facilities increase the amount of PA that visitors obtain while already active at a park.

Capturing fine-scale travel behaviors: a comparative analysis between personal activity location measurement system (PALMS) and travel diary.

BACKGROUND: Device-collected data from GPS and accelerometers for identifying active travel behaviors have dramatically changed research methods in transportation planning and public health. Automated algorithms have helped researchers to process large datasets with likely fewer errors than found in other collection methods (e.g., self-report travel diary). In this study, we compared travel modes identified by a commonly used automated algorithm (PALMS) that integrates GPS and accelerometer data with those obtained from travel diary estimates. METHODS: Sixty participants, who made 2100 trips during seven consecutive days of data collection, were selected from among the baseline sample of a project examining the travel behavior impact of a new light rail system in the greater Seattle, WA (USA) area. GPS point level analyses were first conducted to compare trip/place and travel mode detection results using contingency tables. Trip level analyses were then performed to investigate the effect of proportions of time overlap between travel logs and device-collected data on agreement rates. Global performance (with all subjects' data combined) and subject-level performance of the algorithm were compared at the trip level. RESULTS: At the GPS point level, the overall agreement rate of travel mode detection was 77.4% between PALMS and the travel diary. The agreement rate for vehicular trip detection (84.5%) was higher than for bicycling (53.5%) and walking (58.2%). At the trip level, the global performance and subject-level performance of the PALMS algorithm were 46.4% and 42.4%, respectively. Vehicular trip detection showed highest agreement rates in all analyses. Study participants' primary travel mode and car ownership were significantly related to the subject-level mode agreement rates. CONCLUSIONS: The PALMS algorithm showed moderate identification power at the GPS point level. However, trip level analyses found lower agreement rates between PALMS and travel diary data, especially for active transportation. Testing different PALMS parameter settings may serve to improve the detection of active travel and help expand PALMS's applicability in geographically different urbanized areas with a variety of travel modes.

The accuracy of parent-reported height and weight for 6-12 year old U.S. children.

BACKGROUND: Previous studies have examined correlations between BMI calculated using parent-reported and directly-measured child height and weight. The objective of this study was to validate correction factors for parent-reported child measurements. METHODS: Concordance between parent-reported and investigator measured child height, weight, and BMI (kg/m2) among participants in the Neighborhood Impact on Kids Study (n = 616) was examined using the Lin coefficient, where a value of ±1.0 indicates perfect concordance and a value of zero denotes non-concordance. A correction model for parent-reported height, weight, and BMI based on commonly collected demographic information was developed using 75% of the sample. This model was used to estimate corrected measures for the remaining 25% of the sample and measured concordance between correct parent-reported and investigator-measured values. Accuracy of corrected values in classifying children as overweight/obese was assessed by sensitivity and specificity. RESULTS: Concordance between parent-reported and measured height, weight and BMI was low (0.007, - 0.039, and - 0.005 respectively). Concordance in the corrected test samples improved to 0.752 for height, 0.616 for weight, and 0.227 for BMI. Sensitivity of corrected parent-reported measures for predicting overweight and obesity among children in the test sample decreased from 42.8 to 25.6% while specificity improved from 79.5 to 88.6%. CONCLUSIONS: Correction factors improved concordance for height and weight but did not improve the sensitivity of parent-reported measures for measuring child overweight and obesity. Future research should be conducted using larger and more nationally-representative samples that allow researchers to fully explore demographic variance in correction coefficients.

Effects of a Behavioral Economics Intervention on Food Choice and Food Consumption in Middle-School and High-School Cafeterias.

INTRODUCTION: Changing food choice architecture in school cafeterias through behavioral economics may increase student selection and consumption of healthy foods. However, most research assesses the effects of short-term interventions. We evaluated a year-long choice architecture intervention implemented by school food service staff. METHODS: Food service staff from 6 secondary schools in one school district received training and support to implement behavioral economics strategies in their cafeterias to promote student selection of fruit, vegetables, and low-fat white milk. We compared student selection and consumption of these foods in the intervention schools to 5 comparison schools in the same district on the basis of visual assessment of plate waste. We applied a difference-in-differences approach to estimate intervention effect. RESULTS: Data for 902 students were assessed at baseline, and data for 1,407 were assessed at follow-up. In fully adjusted analyses for all students, there were significantly greater absolute increases in the proportions of intervention school students selecting any fruit, including (0.09) and excluding (0.16) juice, and students selected more fruit items including (0.21) and excluding (0.17) juice. The absolute increase in proportion of intervention students consuming fruit excluding juice (0.14) was significantly greater. However, in some analyses, fewer intervention students who selected fruits or vegetables ate them, or they ate fewer of them. There were no intervention effects for vegetables or low-fat white milk. CONCLUSION: Our results indicate that behavioral economics-based choice architecture can promote student selection of healthy foods, but they raise questions about whether it increases their consumption.

The association between park facilities and the occurrence of physical activity during park visits.

Prior research has found a positive relationship between the variety of park facilities and park-based physical activity (PA), but has not provided an estimate of the effect that additional different PA facilities have on whether an individual is active during a park visit. Using objective measures of park visits and PA from an urban sample of 225 adults in King County, Washington, we compared the variety of PA facilities in parks visited where an individual was active to PA facilities in parks where the same individual was sedentary. Each additional different PA facility at a park was associated with a 6% increased probability of being active during a visit. Adding additional different PA facilities to a park appears to have a moderate effect on whether an individual is active during a park visit, which could translate into large community health impacts when scaled up to multiple park visitors.

The Relationship Between Objectively Measured Walking and Risk of Pedestrian-Motor Vehicle Collision.

Safe urban walking environments may improve health by encouraging physical activity, but the relationship between an individual's location and walking pattern and the risk of pedestrian-motor vehicle collision is unknown. We examined associations between individuals' walking bouts and walking risk, measured as mean exposure to the risk of pedestrian-vehicle collision. Walking bouts were ascertained through integrated accelerometry and global positioning system data and from individual travel-diary data obtained from adults in the Travel Assessment and Community Study (King County, Washington) in 2008-2009. Walking patterns were superimposed onto maps of the historical probabilities of pedestrian-vehicle collisions for intersections and midblock segments within Seattle, Washington. Mean risk of pedestrian-vehicle collision in specific walking locations was assessed according to walking exposure (duration, distance, and intensity) and participant demographic characteristics in linear mixed models. Participants typically walked in areas with low pedestrian collision risk when walking for recreation, walking at a faster pace, or taking longer-duration walks. Mean daily walking duration and distance were not associated with collision risk. Males walked in areas with higher collision risk compared with females, while vehicle owners, residents of single-family homes, and parents of young children walked in areas with lower collision risk. These findings may suggest that pedestrians moderate collision risk by using lower-risk routes.

Physical Activity in Older Adults: an Ecological Approach.

BACKGROUND: Studies identifying correlates of physical activity (PA) at all levels of the ecological model can provide an empirical basis for designing interventions to increase older adults' PA. PURPOSE: Applying ecological model principles, this study concurrently examined individual, psychosocial, and environmental correlates of older adults' PA to determine whether built environment factors contribute to PA over and above individual/demographic and psychosocial variables. METHODS: Using a cross-sectional observational design, 726 adults, aged ≥66 years, were recruited from two US regions. Explanatory variables included demographics, self-efficacy, social support, barriers, and environmental variables measured by using geographic information systems (GIS) and self-report. Outcomes included reported walking for errands and leisure/exercise and accelerometer-measured daily moderate to vigorous PA (MVPA). Analyses employed mixed-model regressions with backward elimination. RESULTS: For daily MVPA, the only significant environmental variable was GIS-based proximity to a park (p < 0.001) after controlling for individual/demographic and psychosocial factors. Walking for errands was positively related to four environmental variables: reported walking/cycling facilities (p < 0.05), GIS-based intersection density (p < 0.01), mixed land use (p < 0.01), and private recreation facilities (p < 0.01). Walking for leisure/exercise was negatively related to GIS-based mixed land use (p < 0.05). Non-Hispanic white race/ethnicity, self-efficacy, and social support positively related to all three PA outcomes (p < 0.05). CONCLUSIONS: Correlates of older adults' PA were found at all ecological levels, supporting multiple levels of influence and need for multilevel interventions. Environmental correlates varied by PA outcome. Walking for errands exhibited the most environmental associations.

Within-person associations of young adolescents' physical activity across five primary locations: is there evidence of cross-location compensation?

BACKGROUND: Youth are active in multiple locations, but it is unknown whether more physical activity in one location is associated with less in other locations. This cross-sectional study examines whether on days with more physical activity in a given location, relative to their typical activity in that location, youth had less activity in other locations (i.e., within-person associations/compensation). METHODS: Participants were 528 adolescents, ages 12 to 16 (M = 14.12, SD = 1.44, 50% boys, 70% White non-Hispanic). Accelerometer and Global Positioning System devices were used to measure the proportion of time spent in moderate-to-vigorous physical activity (MVPA) in five locations: home, home neighborhood, school, school neighborhood, and other locations. Mixed-effects regression was used to examine within-person associations of MVPA across locations and moderators of these associations. RESULTS: Two of ten within-participant associations tested indicated small amounts of compensation, and one association indicated generalization across locations. Higher at-school MVPA (relative to the participant's average) was related to less at-home MVPA and other-location MVPA (Bs = -0.06 min/day). Higher home-neighborhood MVPA (relative to the participant's average) was related to more at-home MVPA (B = 0.07 min/day). Some models showed that compensation was more likely (or generalization less likely) in boys and non-whites or Hispanic youth. CONCLUSIONS: Consistent evidence of compensation across locations was not observed. A small amount of compensation was observed for school physical activity, suggesting that adolescents partially compensated for high amounts of school activity by being less active in other locations. Conversely, home-neighborhood physical activity appeared to carry over into the home, indicating a generalization effect. Overall these findings suggest that increasing physical activity in one location is unlikely to result in meaningful decreases in other locations. Supporting physical activity across multiple locations is critical to increasing overall physical activity in youth.