Portal de Periódicos da CAPES

Role of Built Environments in Physical Activity, Obesity, and Cardiovascular Disease

2012; Lippincott Williams & Wilkins; Volume: 125; Issue: 5 Linguagem: Inglês

10.1161/circulationaha.110.969022

1524-4539

James F. Sallis, Myron F. Floyd, Daniel A. Rodrı́guez, Brian E. Saelens,

Physical Activity and Health

HomeCirculationVol. 125, No. 5Role of Built Environments in Physical Activity, Obesity, and Cardiovascular Disease Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBRole of Built Environments in Physical Activity, Obesity, and Cardiovascular Disease James F. Sallis, PhD, Myron F. Floyd, PhD, Daniel A. Rodríguez, PhD and Brian E. Saelens, PhD James F. SallisJames F. Sallis From the Department of Psychology, San Diego State University, San Diego, CA (J.F.S.); Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, NC (M.F.F.); Department of City and Regional Planning, University of North Carolina, Chapel Hill (D.A.R.); and Seattle Children's Research Institute, University of Washington (B.E.S.). , Myron F. FloydMyron F. Floyd From the Department of Psychology, San Diego State University, San Diego, CA (J.F.S.); Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, NC (M.F.F.); Department of City and Regional Planning, University of North Carolina, Chapel Hill (D.A.R.); and Seattle Children's Research Institute, University of Washington (B.E.S.). , Daniel A. RodríguezDaniel A. Rodríguez From the Department of Psychology, San Diego State University, San Diego, CA (J.F.S.); Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, NC (M.F.F.); Department of City and Regional Planning, University of North Carolina, Chapel Hill (D.A.R.); and Seattle Children's Research Institute, University of Washington (B.E.S.). and Brian E. SaelensBrian E. Saelens From the Department of Psychology, San Diego State University, San Diego, CA (J.F.S.); Department of Parks, Recreation and Tourism Management, North Carolina State University, Raleigh, NC (M.F.F.); Department of City and Regional Planning, University of North Carolina, Chapel Hill (D.A.R.); and Seattle Children's Research Institute, University of Washington (B.E.S.). Originally published7 Feb 2012https://doi.org/10.1161/CIRCULATIONAHA.110.969022Circulation. 2012;125:729–737IntroductionIn industrialized nations like the United States and Sweden, the vast majority of adults do not meet the physical activity guidelines of 150 minutes per week.1 Inactive lifestyles put most adults at risk of cardiovascular diseases (CVDs), diabetes mellitus, obesity, some cancers, osteoporosis, and psychological disorders.2 Physical activity can be effective at all phases of chronic disease management, from primordial prevention (prevention of risk factors) through treatment and rehabilitation.2 There is particular interest in the potential for physical activity to prevent chronic diseases, thereby improving quality of life and reducing healthcare costs.3 In the past decade, limitations of prevention approaches that target mainly individuals with educational and motivational programs have been recognized, triggering a trend to consider influences on behavior that are outside the person, such as the built environment.4,5 The purposes of the present report are to describe multilevel ecological models of behavior as they apply to physical activity, describe key concepts, summarize evidence on the relation of built environment attributes to physical activity and obesity, and provide recommendations for built environment changes that could increase physical activity. The intent of this nonsystematic review is to present conclusions from previous reviews, then illustrate results by highlighting selected studies.An Ecological Model of Physical ActivityEcological models specify multiple levels of influence on behavior, from individual and social factors to institutional, community, built environment, and policy factors. A key principle is that interventions should be most effective when they change the person, the social environment, and built environments and policies.6 Motivating a person to change in an environment that poses many barriers is not expected to be very effective, nor is providing a supportive environment in the absence of educational interventions to promote use of those environments.Built environments are the totality of places built or designed by humans, including buildings, grounds around buildings, layout of communities, transportation infrastructure, and parks and trails.7 Policies can be laws and regulations at any level of government, corporate practices, and rules at institutions such as schools. Changing built environments and policies is expected to have a long-term impact on most or all of the people in those places. Characteristics of built environments, from neighborhoods to cities, have been related to rates of chronic disease and mental health8–10 and risk factors such as obesity11,12 and hypertension.11 Physical activity is believed to be a critical mechanism by which built environments can affect chronic disease.8,9Societal changes over decades have dramatically reduced the need for physical activity in daily life while creating ubiquitous barriers to physical activity. Mechanization and computerization have reduced physical activity at work, labor-saving devices have reduced activity required for household chores, and investments and policies that favored travel by automobiles have reduced the use of walking and bicycling for transportation. Although these societal changes have had some desirable effects, they have also led to a decrease in daily physical activity.Physical activity can be classified into 4 domains of life that describe how people spend their time: Leisure/recreation/exercise, occupation (school for youth), transportation, and household.13 The 4 domains are relevant to and driven by different built environment features and policies. Figure 1 is a simple ecological model of physical activity that identifies institutional and community built environment settings and features, as well as policies, that are relevant to each physical activity domain.Download figureDownload PowerPointFigure 1. An ecological model of 4 domains of physical activity. Adapted from Sallis et al14 with permission of the publisher. Copyright © Annual Reviews, 2006.A commonality across all of the environmental settings identified in Figure 1 (ie, recreation facilities, community design, transportation facilities, workplaces, schools, and homes) is that none are controlled by health professionals. Yet these places can affect health. Thus, for both research and practical applications, it is necessary for health professionals to develop partnerships with professionals from diverse and often unfamiliar disciplines and sectors of society.14The need for a multilevel, multisector approach to physical activity promotion, obesity, and CVD prevention has been recognized by numerous health organizations.4,15–18 These recommendations justify a vigorous research program to identify modifiable environmental attributes and policies that have the strongest or most widespread effects or associations to guide intervention efforts. The Active Living Research program of The Robert Wood Johnson Foundation has been funding such studies since 2003,19 and the US National Institutes of Health (NIH) includes environment and policy research in the Strategic Plan for NIH Obesity Research.20 Environmental research on physical activity has grown rapidly since 2000, has been reviewed numerous times,21–24 and is informing policy debates at all levels of government.Because investigators do not have control over the policy or environment intervention, it is rarely possible to randomly assign people or places to experimental conditions. Thus, most of the studies are observational, although quasi-experimental studies have become more common. In the present nonsystematic review, overviews of the literature are provided and illustrative results are described as they relate to active transportation and active recreation, because these physical activity domains appear most amenable to environment and policy intervention. Because there is limited evidence about how built environments are related to occupational and household physical activity, these domains were not addressed.Built Environments and Active RecreationHealthy People 202025 and the Institute of Medicine16 identified public parks and recreation facilities as providing settings for diverse recreation activities for children, families, and organizations such as schools and faith-based institutions. Provision of parks and recreation is a function of government in all developed countries. In the United States, parks are administered by municipal, county, state, and federal levels of government, as well as special park districts.26 There are more than 9000 local park and recreation departments with 108 000 public park facilities and 65 000 indoor recreation facilities in the United States.27 Because parks and recreation facilities are generally accessible to populations at highest risk of inactivity and are available at low user costs, they are well positioned to play a role in disease prevention. Their provision, design, and quality can be influenced through public policy.26,28Recreation Environments and Active RecreationAvailability of and proximity to recreation facilities have been associated consistently with greater physical activity among adults,29–32 adolescents,33–35 and children,33,34,36,37 with some exceptions.38 A national study of U.S. adults found perceived access to parks and trails was positively associated with physical activity.29 Respondents perceiving access to these resources were nearly 2 times more likely to meet physical activity guidelines than those who did not perceive these resources were available. A 3-city study found that objectively measured density of parks and recreation facilities was associated with physical activity among adults.30 An observational study39 in Tampa, FL, and Chicago, IL, assessed energy expenditure associated with different activity zones in 28 neighborhood parks. Courts (basketball and racquet sports), playgrounds, and soccer fields generally were associated with greater energy expenditure than baseball/softball fields, picnic areas, and open spaces (Figure 2).Download figureDownload PowerPointFigure 2. Mean energy expenditure (kcal · kg−1 ·min−1) per park in 10 Tampa, FL, neighborhood parks by activity zones (N=6922). Adapted from Floyd et al39 with permission of the publisher. Copyright © Elsevier, 2008.Trails and greenways can be used for active recreation and active commuting. People who used trails on a weekly basis were twice as likely to meet physical activity recommendations.40 A study in Dallas, TX, Chicago, and Los Angeles, CA, demonstrated that greater trail usage was associated with trail characteristics such as mixed views (a combination of urban and natural scenery), lighting, good trail conditions, cafes, and restrooms.41 Lower usage was associated with litter, noise, and high density of vegetation on the trails.Similar results were found in studies of adolescents and children. A national study of 17 000 adolescents found that odds of participating in frequent physical activity were greater when there were more recreation facilities nearby (Figure 3).34 A large study36 of Atlanta, GA, youth found that the presence of recreation space within 1 km of home was related to walking trips among all age groups (ages 5–20 years) and was the strongest predictor of walking among youth in the 15- to 20-year-old age group. Cohen et al33 found that parks with playgrounds, basketball courts, walking paths, tracks, swimming areas, and multiple purpose rooms were associated with greater nonschool physical activity among adolescent girls. Thus, presence of parks and trails, as well as the design of these facilities, has been related to physical activity.Download figureDownload PowerPointFigure 3. Relative odds of overweight and >5 bouts of moderate to vigorous physical activity (MVPA) with increasing number of recreation facilities per block group, adjusted for population density. Adapted from Gordon-Larsen et al34 with permission of the publisher. Copyright © American Academy of Pediatrics, 2006.Recreation Environments and ObesityThere is limited research on the link between access to recreation environments and weight-related outcomes. Findings generally do not support associations between recreation environments and obesity for either adults or youth.12 This is not surprising, because recreation environments are just 1 component of the built environment. One notable exception was a US national study of adolescents that found odds of being obese were lower among youth in neighborhoods with more recreation facilities (Figure 3).34Interventions and Active RecreationA few studies evaluated the impacts of environmental interventions in park and recreation settings using quasi-experimental designs. For instance, a study conducted in ethnically diverse communities in San Francisco, CA, compared visitation and physical activity in 2 renovated parks to a control park.42 Renovations included turf replacement, new fencing and lighting, and additional programming. Both intervention parks experienced a significant increase in youth and adult visitors. Another study investigated whether expansion of a skate park and improvements to a community center for older adults (eg, building renovations and the addition of exercise equipment) were related to facility use and physical activity, with comparisons to 2 control parks.43 Renovation of the skate park was associated with a 6-fold increase in use and more physical activity. Use levels of the renovated senior center actually declined compared with baseline and were not significantly different from control parks. The researchers suggested the decline might be explained by park users not being aware of the renovations. This highlights the importance of coupling informational and environmental interventions, consistent with ecological models.44Built Environments and Active TransportationActive transportation has declined in recent decades. Between 1977 and 1995, the number of all walking trips decreased by 32% for adults, with similar reductions for youth.45 Adults walk for only 21.2% of trips that are 1.6 km or less, and children walk for only 35.9% of trips to school of that distance.45 Reversing the recent decline in rates of walking and biking for transportation, especially for short trips, presents a major opportunity for improving health for all ages. Evidence is accumulating about how the built environment can support active transportation, and this evidence can inform policy changes.Built Environment, Active Transportation, and Physical ActivityKey characteristics of built environments and community design are land use (residential, commercial, institutional, or park and open space), intensity (population density), location relative to other community destinations, the interconnections available to reach those destinations, and aesthetic qualities. Having a variety of destinations close by has been positively associated with walking and bicycling for transportation.22,23,46–48 Destinations refer to land uses that are frequently accessed in daily life for shopping, education, work, and recreation. Proximity to parks and commercial areas is associated with higher active transportation.24,49Population density refers to the number of individuals or households living in a particular area and is consistently associated with higher active transportation.23,46 In areas of high density, destinations can be closer together because the number of people needed to support shops, services, and schools is found in a smaller area.Transportation facilities that connect residential areas and destinations also are related to active transportation. When neighborhoods have sidewalks, streets are well lit, and pedestrians are shielded from traffic, residents are often found to walk more and have higher physical activity, although results are not highly consistent.46,47,50,51 Having bicycle paths or trails that separate bicycles from traffic is sometimes associated with increased bicycle use.48,52Public bus and rail stops nearby have been positively associated with active transportation.51,53,54 People who use public transportation tended to be more active and less likely to be overweight and obese than adults who did not use public transportation.55 Nationwide, 29% of those who used transit were physically active for 30 minutes or more each day, solely by walking to and from public transit.54Many of the environmental factors associated with active transportation among youth are similar to findings with adults. Two reviews56,57 found consistent evidence that proximity to destinations and the presence of paths for walking and bicycling are important for active transportation among youth.58 Living in neighborhoods with high density and a variety of nonresidential land uses such as parks, play areas, and recreational facilities is associated with higher rates of active transportation in children58 and overall physical activity.57 One difference from the evidence on adults is that for children, the importance of commercial uses close to home is more equivocal.58A commonality across adults and children is the concern regarding safety from traffic as a barrier to physical activity. Parental concern about personal and traffic safety has been associated with whether children are allowed to walk or bicycle in their community or to and from school.56,59 Focusing on behavior-specific correlates, such as with active transport to school, promises to clarify associations and provide more concrete guidance regarding environmental interventions.57,60 Higher rates of walking to school have been consistently associated with closer proximity to school, greater population density, and supportive pedestrian infrastructure and safety conditions on the route.57,59,60 Active transportation to school supplements, and does not replace, other physical activity.56Many of the built environment characteristics described often occur simultaneously in urban areas. Places with high density usually are well connected, have destinations close by, and are well served by infrastructure for walking, bicycling, and public transportation. This covariation suggests that isolating the effects of built environment characteristics on physical activity outcomes is methodologically difficult and may be conceptually unwise, because cumulative effects of several environmental attributes may be required to have a large effect on behavior. Some studies have focused on the package of attributes by sampling individuals from neighborhoods deemed a priori as highly supportive or unsupportive of physical activity. Although not unanimous,22 the evidence consistently indicates that walking is higher in high-walkable neighborhoods than in low-walkable neighborhoods. A walkable environment was defined on the basis of its land use mix, street connectivity, residential density, and retail intensity. In a study of 32 neighborhoods in Seattle, WA, and Baltimore, MD, regions, neighborhood walkability was related to both higher reported walking for transportation (20–40 more minutes per week) and higher objectively measured total physical activity (35–49 more minutes per week).61 An international study showed adults in the most activity-supportive environments were twice as likely to meet physical activity guidelines as those in the least-supportive neighborhoods.51There are fewer studies focusing on rural populations, even though rural residents are at high risk of poor health outcomes.62 For rural residents, traffic safety, recreation facilities, and trails were most consistently associated with physical activity.Built Environments and ObesityStudies on associations between the built environment and obesity have produced mixed findings in adults. Although some neighborhood studies found that walkable neighborhoods protect against overweight and obesity,61,63 a review concluded there are inconsistent associations of walkable neighborhoods and their components with obesity-related outcomes.46 Body fat accumulates over time, so studies of cumulative exposures rather than cross-sectional associations may be more likely to detect impacts of the built environment. Alternatively, cross-sectional associations could be caused by self-selection bias and not be confirmed in longitudinal studies. A large study showed significant cross-sectional but not longitudinal associations between built environments and weight status.64 It is possible that longitudinal changes in built environments must be substantial and well measured to detect associations with change in body mass index.Among children, the evidence on associations between the built environment and obesity or overweight appears equally mixed. Galvez et al65 reported that although most built environment variables were not associated with childhood obesity in 15 studies, distance to playgrounds and density of rail stations were associated with obesity in the anticipated direction. In a prospective study, active commuters to school had significantly lower body mass index than nonactive commuters, but active commuting to school was not associated with body mass index change.66Interventions and Active TransportationAlthough brick-and-mortar solutions are important, research has emphasized the importance of programming and policies to support infrastructure changes. Programming for active transportation to schools (such as safe routes to school and the walking school bus) has been associated with increased physical activity among children, although the studies are methodologically weak.67 Policies play a crucial role in encouraging active transportation. A review concluded there is sufficient evidence that community-scale land use regulations and policies can be effective in increasing walking and bicycling.68 Policies also support complementary strategies such as programs and promotions to encourage active transportation. This is particularly apparent in interventions to promote bicycling, in which single strategies had little effect, but uncontrolled evaluations of cities that used multiple strategies, including protected bicycle facilities, bicycle sharing, and policies favoring cyclists, appeared to be consistently effective.69Disparities in Access to Activity-Supportive Built EnvironmentsDisparities in Access to Parks and Recreation FacilitiesIn light of the potential of parks and recreation facilities to increase physical activity, understanding the extent of their availability and quality in low-income and racial/ethnic minority communities is of importance in efforts to eliminate health disparities. A national study34 showed that areas with college educated populations were 3 and 4 times more likely, respectively, to have at least 1 park or other outdoor recreation resource than areas with less educated residents. Neighborhoods with populations that were 95% minority and overwhelmingly without college education (5% or less) had 46% lower odds of having at least 1 recreation facility. Having a recreation facility nearby is only 1 aspect of addressing income and ethnic disparity. Quality of facilities, safety, and recreation preferences of community members should also be considered.Disparities in Built Environments Relevant to Active TransportationIt appears that disparities in access to activity-supportive community environments vary across attributes. There is little evidence that Hispanics and blacks, or low-income populations, are disadvantaged with respect to the density of areas in which they live.70,71 Racial and ethnic minority and low socioeconomic status groups may be particularly sensitive to the built environment. In a review, light traffic, safety from crime, and sidewalks were most consistently associated with physical activity among black Americans.71 However, low socioeconomic status or high-minority neighborhoods appear to have less supportive environmental conditions for active transportation. A review concluded that disadvantaged neighborhoods had poorer aesthetics and worse conditions related to traffic safety and crime safety.71 For example, a study of 2 US regions found that lower- and higher-income neighborhoods did not differ substantially with regard to commonly assessed walkability variables, but lower-income neighborhoods had less favorable values on pedestrian/cycling facilities, aesthetics, access to recreation facilities, traffic safety, and crime safety.72 These poor conditions could potentially overcome the beneficial effects of living in a walkable low-income neighborhood.Recommendations for Environment and Policy ChangeRecent recommendations for increasing physical activity and reducing obesity and CVD risk retain some educational focus (eg, benefits of physical activity, behavior change skills), but most emphasize more sustainable and broader-reaching environmental and policy changes. Various organizations' recommendations15,16,73–77 in these areas are provided in the Table, with sample strategies that target environmental or policy change. These recommendations have different desired outcomes (eg, obesity prevention versus physical activity promotion only) but considerable overlap in the types of proposed intervention strategies.Table. Recent U.S.-Based Recommendations for Modifying Built Environments or Policies for Physical Activity Promotion, Obesity Prevention, and Cardiovascular Disease Risk ReductionSourcePrimary Target(s)Levels of InterventionExample Built Environment or Policy Recommendation for Increasing Physical ActivityWeb AccessAmerican Academy of Pediatrics (2009)73Physical activity promotion in childrenCommunity"Create and maintain playgrounds, parks, and green spaces [and] means to access them safely"http://aappolicy.aappublications.org/cgi/collection/committee_on_environmental_healthAmerican Heart Association Policy Strategies (2011)15Ideal cardiovascular healthCommunity, food supply, healthcare system, media, restaurants, schools, worksites"Implement zoning/building ordinances that encourage pedestrian-friendly streets and roadways with appropriate crosswalks, sidewalks, traffic lights, etc and slower speed limits in walking/biking areas"http://circ.ahajournals.org/cgi/content/full/123/7.816CDC MAPPS interventions for CPPW74Obesity preventionCommunity, food retailers, media, recreational facilities, restaurants, schools, worksitesProvide "incentives for active transit"http://www.cdc.gov/CommunitiesPuttingPreventiontoWork/strategies/index.htmCDC Recommended Strategies for Obesity Prevention (2009)75Obesity preventionCommunity, public service venues, schools"Zone for mixed-used development"www.cdc.gov/obesity/downloads/community_strategies_guide.pdfInstitute of Medicine (2009)16Childhood obesity preventionCommunity, retail food outlets and restaurants, worksites, childcare, government nutrition assistance programs"Adopt community policing strategies that improve safety and security for park use, especially in higher crime neighborhoods"http://www.nap.edu/catalog/12674.htmlNational Physical Activity Plan76Physical activity promotion"Increase accountability of project planning and selection to ensure infrastructure supporting active transportation and other forms of physical activity"http://www.physicalactivityplan.org/White House Task Force on Childhood Obesity (2010)77Childhood obesityFederal and state government and agencies, and local community, schools, local businesses and other private sector partners (eg, entertainment companies)"The Environmental Protection Agency should assist school districts that may be interested in siting guidelines for new schools that consider the promotion of physical activity, including whether students will be able to walk or bike to school"http://www.letsmove.gov/white-house-task-force-childhood-obesity-report-presidentCDC indicates Centers for Disease Control and Prevention; MAPPS, Media, Access, Point of decision information, Price, and Social support/services; and CPPW, Communities Putting Prevention to Work.As seen in the Table, the recommendations target many of the contexts encountered in daily living, such as transportation systems, neighborhood built environments, schools, worksites, and the media. These recommended strategies are also broad in type, targeting changes in physical activity across multiple domains, from encouraging changes to the availability of resources for leisure-time physical activity (eg, more parks and green space) to changes in zoning and land use patterns expected to impact transportation choices.An example set of recommendations is the American Heart Association's recent policy strategies for achieving ideal cardiovascular health published in Circulation.15 In addition to an emphasis on the healthcare system, the recommendations include strategies for targeting built environment (eg, walk/bike trails, safe routes to schools) and policy interventions (eg, shared-use agreements for recreational facility use between schools and communities). The predecessor to these strategies within the American Heart Association appears to be the 2003 guide for improving cardiovascular health at the community level,5 which included many of the same environment and policy recommendations. It is noteworthy that the more recent recommendations had considerably less focus on individual-level education (eg, school curriculum about CVD risks), perhaps recognizing the need to prioritize environment and policy changes before expecting educational interventions to be effective.From Recommendations to InterventionsRecommendations summarized in the Table, based on limited evidence and often expert opinion, have gu