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Active Commuting to Elementary School and Adiposity: An Observational Study
Abstract
Background:
Active commuting to school (ACS; walking or cycling to school) appears promising for decreasing children's obesity risk, although long-term studies are sparse. The aim was to examine whether kindergarten ACS was associated with fifth-grade adiposity.
Methods:
This study was a secondary analysis of the Early Childhood Longitudinal Study, Kindergarten (n=7938). Enrollment in kindergarten (1998-1999) was nationally representative of the United States and follow-up occurred in 2004. Kindergarten ACS was the main exposure variable and fifth-grade BMI z-score was the main outcome measure. Covariates included (1) neighborhood safety and BMI z-score in kindergarten and (2) demographics (i.e., age, gender, race/ethnicity, socioeconomic status, single- vs. two-parent households, region of country, and urbanicity in fifth grade). Three interactions were included: school travel*neighborhood safety; school travel*BMI z-score (kindergarten); and school travel*socioeconomic status. Analysis of covariance accounted for the complex sampling design.
Results:
Kindergarten ACS was associated with lower BMI z-score in fifth grade. The interaction of school travel*neighborhood safety indicated that children from less-safe neighborhoods who did ACS in kindergarten had a lower fifth-grade BMI z-score (p<0.05) than their peers who did not do ACS in kindergarten (i.e., in terms of BMI, this difference was -0.49 kg/m(2) for children of average height in less-safe neighborhoods).
Conclusion:
Among children from less-safe neighborhoods, kindergarten ACS independently predicted lower BMI z-score in fifth grade among a national US cohort. Interventions and policies to increase ACS among young children, especially from unsafe neighborhoods, are warranted and should address parents' safety concerns.
... Diversos estudos apontam a relevância que o TA pode ter na saúde e na vida dos escolares, bem como na qualidade de vida das pessoas [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Quanto aos aspectos metodológicos, os 16 estudos foram de abordagem quantitativa, sendo a maioria (n=14) transversal. As amostras variaram entre 59 e 61.301 participantes (crianças e jovens escolares). ...
... Além disso, o TA esteve associado positivamente com os níveis de ativ idade física 20,21 e negativamente associado com a chance de sobrepeso/ obesidade14, 15,18,23 . Cada minuto a mais de transporte ativo, diminui em 1% a chance de sobrepeso/obesidade 15 , bem como TA maior que meia milha (804 metros) reduz em 65% a chance de est ar acima do peso/obeso 14 e TA no jardim de infância foi associado a menor IMC na 5ª série 18 . A distância do trajeto escolar ativo por volta de 2 km foi associada a melhores níveis de atividade física relacionada ao TA (aumento de 9% a 15% nos dias da semana) 20 . ...
... Os pais usarem transporte ativo estimula os estudantes a também praticarem esse modal no trajeto escolar17 . Algumas barreiras relacionadas com a percepção dos pais são: crianças devem ficar dentro do campo de visão dos pais ou da casa, e mais horas de trabalho dos pais17 .Por outro lado, são características que incentivam o TA no caminho escolar: crianças mais velhas 17 , sem irmãos e sem veículos10 ; escolas e crianças de grandes cidades, com menor satisfação familiar ou que tem maior número de dias fisicamente ativos 12 ; ser da área rural e escolaridade da mãe a partir de oito anos18 . Em adição, outro estudo 22 mostra que ser homem, presença de um adulto, expectativa dos desfechos dos pais e a temperatura podem colaborar para o TA escolar. ...
o transporte ativo no trajeto escolar pode ser uma oportunidade interessante para desenvolver comportamentos mais promotores de saúde na vida das crianças e jovens. O presente trabalho realiza uma revisão de literatura sobre transporte ativo no trajeto escolar, buscando identificar barreiras e facilitadores desse comportamento, bem como suas interfaces com a saúde dos escolares. Trata-se de uma revisão integrativa de literatura realizada nas bases eletrônicas BVS, Scielo e periódico Capes, utilizando os descritores mobilidade, transporte, deslocamento, ativo, sustentável, estudantes, escolares e trajeto escolar em português, inglês e espanhol. Foram incluídos estudos realizados nas Américas e publicados nos últimos cinco anos em português, inglês ou espanhol. Os estudos foram elaborados no Brasil, no Canadá, no México e nos Estados Unidos, que por sua vez, lideram as produções científicas nessa temática. A maioria dos estudos selecionados é secundário de outras pesquisas maiores já realizadas. Resultados dos 16 trabalhos selecionados indicam que a prevalência de transporte ativo no trajeto escolar variou entre 10,0% nos Estados Unidos e 75,7% no Brasil, uma vez que a barreira mais relatada foi a distância, além de aspectos como segurança pessoal. A interface do transporte ativo no trajeto escolar com a saúde se realiza em estudos que se relacionam com nível de atividade física, obesidade/sobrepeso (saúde individual) e barreiras e facilitadores a esse tipo de deslocamento (saúde ambiental). Considerando que atitudes cultivadas na infância têm grandes chances de permanecer na vida adulta, o transporte ativo no trajeto escolar pode ser uma estratégia na criação de hábitos saudáveis e sustentáveis que contribuam para melhor qualidade de vida, desde que se considerem seus determinantes e condicionantes.
... Out of 13 studies, three conclusively confirmed existence of associations between ATS and BMI (Larouche et al. 2011;Sarmiento et al. 2015;Sun et al. 2015), three partially confirm such associations in certain conditions (Rosenberg et al. 2006;Mendoza et al. 2014;DeWeese and Ohri-Vachaspati, 2015), and seven reject any association (Fulton et al. 2005 (Table 3). Table 3 did not report clearly about the modes of active transport to school in their study, only Yeung et al. (2008) took a one-mode ATS (walking). ...
... Australia, Norway, Sweden, Spain, and China had each one, and one study was international(Table 3). Four studies are longitudinal(Rosenberg et al. 2006;Pabayo et al. 2010;Chillón et al. 2012;Mendoza et al. 2014), which provides a higher quality in discussing causation than the existing evidence back in 2011 byLubans et al. (2 out of 27 which equals 7.4%). ExceptFulton et al. (2005) andDeWees & Ohri-Vachaspati(2015), who applied random-digit dial survey, others took self-reported questionnaires for collecting ATS and other data. ...
... OnlyYeung et al. (2008) did not observe bicycle trips. ATS ranged from 8.67%(Mendoza et al. 2014) to 69%(Gutiérrez-Zornoza et al. 2015) within the children of the samples, both conducted in the US. ...
Because of decreasing physical activity of children, they are becoming more obese. Moreover, commuting to school has become more passive during the past decades. The objective was to update the previous systematic reviews by narrowing down the topic to body mass index of children (3-12 years) as a representative of body composition. Applying search terms such as active transport to school, body mass index, childhood obesity, and so on in four online databases: PubMed, ScienceDirect, WorldCat, and Google Scholar. Peer reviewed English journal papers published between 2005 and 2015 presenting empirical quantitative studies were eligible studies to be reviewed. 310 journal papers were screened, 27 of which were reviewed by studying the full text. The final 13 papers were limited to those that focused only on active commuting to school and body mass index of children and adolescents. Out of 13 final studies, 3 found conclusive associations, three indicate partial associations in subgroups or societal or geographical limitations, and seven show no correlations. The existing literature are still inconsistent, so this study suggests conducting surveys with larger samples on less-studied contexts and applying more complex statistical methods for adjusting some of the variables. It is also argued that this topic can be culturally and contextually specific.
... With the growing global childhood obesity epidemic, the importance of physical activity (PA) in children is more apparent [1][2][3] . Active travel to school (ATS), defined as walking or bicycling, is an important contributor to a child's overall PA 4,5 and may be associated with various positive health indicators [6][7][8][9][10] . Although the evidence for ATS to promote healthy body weight for children is still mixed 8,9,11,12 , some findings indicate that ATS is associated with better waist circumference 6 , increased cardiovascular fitness [13][14][15] and better high-density lipoprotein cholesterol profiles 6 . ...
... Active travel to school (ATS), defined as walking or bicycling, is an important contributor to a child's overall PA 4,5 and may be associated with various positive health indicators [6][7][8][9][10] . Although the evidence for ATS to promote healthy body weight for children is still mixed 8,9,11,12 , some findings indicate that ATS is associated with better waist circumference 6 , increased cardiovascular fitness [13][14][15] and better high-density lipoprotein cholesterol profiles 6 . Importantly, one recent study found that children who engage in ATS are more likely to maintain a healthy lifestyle into adulthood. ...
Background:
Active travel to school (ATS) is positively associated with various health indicators. The rapid social, economic and environmental changes in China provide a unique setting to study changes and predictors of ATS over time.
Methods:
Using logistic regression modeling, we analyzed data from the China Health and Nutrition Survey during 1997-2011 (N=9487, ages 6-17 years) to estimate the change over time in ATS and to identify associated factors.
Results:
The prevalence of reported ATS among children dropped from 95.8% in 1997 to 69.3% in 2011. ATS was common in children living closer to school, in middle school, from low-income households, with low parental education status, and those without a private vehicle. Children who were living in a metropolitan area and who had more than 40 minutes of total PA per day were less likely to report ATS.
Conclusions:
The decrease of ATS had been concurrent with the increase of the children living at a longer distance from school and the increase of household owning private vehicles which were associated with the rapid urbanization and economic growth in China. Factors associated with the decreased ATS in China are similar to other countries but the underlying reasons may be different.
... McKay et al., 2015;Menai et al., 2015;Mwaikambo et al., 2015;Olabarria et al., 2014;Pearson et al., 2014;Rissel et al., 2014;Sarmiento et al., 2015;Schauder and Foley, 2015;Scheepers et al., 2015;Sugiyama et al., 2016;Sun et al., 2015;Wojan and Hamrick, 2015;Ding et al., 2014;Falconer et al., 2015;Martinez-Gomez et al., 2014;Mendoza and Liu, 2014;Skreden et al., 2016;Flint et al., 2014). Interestingly though, only thirteen studies (39%) controlled for diet in some wayWanner et al., 2016;Berglund et al., 2016;Fernandez et al., 2015;Flint and Cummins, 2016;Laverty et al., 2015;McKay et al., 2015;Olabarria et al., 2014;Rissel et al., 2014;Schauder and Foley, 2015;Sugiyama et al., 2016;Skreden et al., 2016;Flint et al., 2014) and 20 (61%) controlled for PA in a domain other than transportation(Flint and Cummins, 2016;Gutiérrez-Zornoza et al., 2015;Larouche et al., 2014b;Laverty et al., 2015;Machado-Rodrigues et al., 2014;McKay et al., 2015;Menai et al., 2015;Olabarria et al., 2014;Rissel et al., 2014;Sarmiento et al., 2015;Schauder and Foley, 2015;Scheepers et al., 2015;Sugiyama et al., 2016;Sun et al., 2015;Wojan and Hamrick, 2015;Ding et al., 2014;Martinez-Gomez et al., 2014;Skreden et al., 2016;Flint et al., 2014). ...
... The mean score for strength of evidence assessment across primary studies was 7 out of a possible 13 points (range 4 to 9) (Appendix D). Twenty-seven studies published since 2014 used a cross-sectional study design (82%) Wanner et al., 2016;Berglund et al., 2016;Bopp et al., 2014;Dąbrowska et al., 2015;Fernandez et al., 2015;Flint and Cummins, 2015;Flint and Cummins, 2016;Gutiérrez-Zornoza et al., 2015;Jáuregui et al., 2015;Larouche et al., 2014b;Laverty et al., 2015;Machado-Rodrigues et al., 2014;McKay et al., 2015;Menai et al., 2015;Muthuri et al., 2014;Mwaikambo et al., 2015;Olabarria et al., 2014;Pearson et al., 2014;Rissel et al., 2014;Sarmiento et al., 2015;Schauder and Foley, 2015;Scheepers et al., 2015;Sugiyama et al., 2016;Sun et al., 2015;Wojan and Hamrick, 2015;Ding et al., 2014), with only 6 undertaking a longitudinal study (18%) Martin et al., 2015;Martinez-Gomez et al., 2014;Mendoza and Liu, 2014;Molina-GarcÍa et al., 2015;Skreden et al., 2016). Over half of all studies (54%) reported on combined modes of transport (AT or private transport) Wanner et al., 2016;Berglund et al., 2016;Bopp et al., 2014;Fernandez et al., 2015;Gutiérrez-Zornoza et al., 2015; ...
... Studies conducted across multiple countries have consistently shown that children who walk or bike to school have higher daily levels of physical activity (PA) than those who travel to school by car or bus [1,2]. Some studies have even shown active commuting to school to be associated with better weight and metabolic outcomes [3,4], and biking to school to be associated with higher cardiorespiratory fitness [5,6]; however, results across studies have been less consistent [7]. While active commuting appears to have important health benefits, the proportion of students who walk or bike to school in the US has declined substantially over the past 40 years [8,9]. ...
... Another underlying factor identified by McDonald et al. influencing this relationship between ethnicity/race and active school travel was income [35]. Income is commonly studied socio-demo graphic variable, and generally, studies indicate that children from a low socio-economic status (SES) background are more likely to walk or bike to school than children with a higher SES [3,34,37,40,41]. In the present study, household income was not assessed, but the percentage of students receiving free or reduced lunch (an indicator of SES at the school level) was not significantly related to active school travel. ...
Background
Promoting daily routine physical activities, such as active travel to school, may have important health implications. Practitioners and policy makers must understand the variety of factors that influence whether or not a child uses active school travel. Several reviews have identified both inhibitors and promoters of active school travel, but few studies have combined these putative characteristics in one analysis. The purpose of this study is to examine associations between elementary school children’s active school travel and variables hypothesized as correlates (demographics, physical environment, perceived barriers and norms).
Methods
The current project uses the dataset from the National Evaluation of Walk to School (WTS) Project, which includes data from 4th and 5th grade children and their parents from 18 schools across the US. Measures included monthly child report of mode of school travel during the previous week (n = 10,809) and perceived barriers and social norms around active school travel by parents (n = 1,007) and children (n = 1,219). Generalized linear mixed models (GLMM) with log-link functions were used to assess bivariate and multivariate associations between hypothesized correlates and frequency of active school travel, assuming random school effect and controlling for the distance to school.
Results
The final model showed that the most relevant significant predictors of active school travel were parent’s perceived barriers, specifically child resistance (Estimate = −0.438, p < 0.0001) and safety and weather (Estimate = −0.0245, p < 0.001), as well as the school’s percentage of Hispanic students (Estimate = 0.0059, p < 0.001), after adjusting for distance and including time within school cluster as a random effect.
Conclusions
Parental concerns may be impacting children’s use of active school travel, and therefore, future interventions to promote active school travel should more actively engage parents and address these concerns. Programs like the Walk to School program, which are organized by the schools and can engage community resources such as public safety officials, could help overcome many of these perceived barriers to active transport.
... Active commuting, in the forms of walking or cycling, followed the overall trend of physical activity decrease, and has consistently been declining over the last 30 years (Mendoza & Liu, 2014). Some authors suggest that various interventions are needed to reverse this trend (Villa-González et al. 2018). ...
Active commuting is considered one of the many forms of physical activity that could increase the level of physical activity among school children. The aim of the current study was to examine the differences between the health-related fitness of school children who engage in active and passive commuting to school, and to explore the associations between active commuting to school and the health-related physical fitness of school children. A total of 152 children (58 girls and 94 boys), aged 12, from four primary schools in the Kraljevo area participated in this study. Basic anthropometric measures were taken along with eight physical fitness tests. Boys who actively commute had greater upper body muscular endurance and cardiorespiratory fitness, and girls who were active school commuters had better results in flexibility, explosive power, upper body muscular endurance, and cardiorespiratory fitness. Linear regression analysis revealed significant associations between active commuting, and abdominal strength and cardiorespiratory fitness for boys, and flexibility and upper body muscular endurance for girls. Considering these positive findings, it is recommended that future studies be conducted on a larger sample and that they include intensive educational campaigning to encourage Serbian schoolchildren to practice active commuting to and from school is likewise recommended. Апстракт Активни транспорт се сматра једном од многих форми физичке активности које могу да повећају ниво физичке активности код школске деце. Циљ овог истражива-ња био је да се испитају разлике између ученика који користе активни и пасивни транспорт до школе у нивоу здравствено усмереног фитнеса, као и да се истраже ве-зе између активног транспорта до школе и здравствено усмереног фитнеса код уче-ника основне школе. Истраживањем је обухваћено укупно 152 ученика (58 девојчи-ца и 94 дечака), старости 12 година из четири основне школе са подручја града Кра-љева. Измерене су основне антропометријске мере и примењено је осам тестова за процену физичке спремности. Дошло се до сазнања да су дечаци који практикују активни транспорт имали већу мишићну издржљивост горњег дела тела и виши ни-во кардиореспираторне спремности, а да су девојчице које активно путују до школе и назад имају бољу флексибилност, експлозивну снагу ногу, мишићну издржљивост горњег дела тела и кардиореспираторну спремност. Резултати линеарне регресионе анализе су показали значајну повезаност између активног транспорта, снаге мишића абдомена и кардиореспираторног фитнеса код дечака, те флексибилности и мишић-не издржљивости горњег дела тела код девојчица. Имајући у виду позитивне резул-тате овог истраживања, препоручује се да будућа истраживања обухвате већи узорак и интензивне образовне кампање, како би се школска деца у нашој земљи подстакла да у већој мери практикују активни транспорт до и из школе. Кључне речи: школска деца, физичка активност, моторичке способности.
... Physical activity is associated with health benefits in school-aged children, including positive, lasting impacts on physical health, cognitive function, academic performance and mental health (Janssen and LeBlanc, 2010;Rothman et al., 2016). It also reduces obesity in childhood through to adulthood and reduces the risk of several chronic and cardiovascular diseases (Mendoza and Liu, 2014;Mitra, 2013;Rothman et al., 2016). Despite these benefits, most children do not meet recommended physical activity guidelines, including 60 min of moderate to vigorous activity everyday (Hills et al., 2011;ParticipACTION, 2018). ...
Active school transportation (AST) benefits children’s health. Social factors, including low-income, visible minority status, and immigration have been associated with more AST. However, the mechanism by which they influence AST is not well understood, nor is their interaction with built environment features. This cross-sectional study examined associations between area-level social factors (material deprivation, ethnic concentration, proportion recent immigrants, proportion visible minority), and AST across 105 elementary schools in Toronto, Canada, controlling for multi-dwelling density and Walk Score®. A significant association between proportion recent immigrants and AST was found in adjusted analyses (OR = 1.54, 95 %CI:1.14–2.07, per 10% increase). No significant association was found with other social factors. In analyzing effect modification, social factors appeared to have stronger associations with AST in less walkable environments. This analysis indicates that the influence of the built environment varies across social factors, suggesting the need to account for equity when promoting active travel to school.
... A singlelevel intervention to promote active commuting to school in preschool children might be insufficient to achieve a behavior change due to the complexity of the behavior [41]. Thus, as a first step, it might be important for parents to be aware of the benefits of the active commuting to school behavior in preschool children, such as its association with better body composition or a better physical fitness level because of the increase of a daily step count [42,43], and its influence in the health later in live [44]. After this parental sensibilization, educational strategies for preschool children and their parents throught intervention programs in the community, built environment modifications, and policy measure at school level might be introduced. ...
The aims of this study were to describe patterns of active commuting to school (ACS) of preschool children, and to analyse the relationship between ACS and family socio-economic factors. A total of 2636 families of preschoolers (3-to-5 years old) were asked to complete a questionnaire at home about the mode of commuting to school of their children and marital status, educational level, and profession of both father and mother. Chi-square analyses were applied to compare ACS between school grades and gender of the children. To analyse the association of ACS with socio-economic factors, logistic regression analyses were performed. Almost 50% of participants reported ACS of their offspring, with a higher rate in 3rd preprimary grade (5 years old) than in 1st and 2nd preprimary grades (3- and 4-years old. All, p < 0.05). Those preschool children who had parents with lower educational level and no managerial work had higher odds to ACS than those who had parents with higher educational level and managerial work (all, p ≤ 0.001). Around half of the Spanish preschool children included in this study commuted actively to school and families with lower educational levels or worse employment situation were related to active commuting to school.
... 2. It could be assumed that increasing ambulatory activity volume and intensity is a feasible form of PA that can increase the chances of meeting PA recommendations in this population. This is especially important to consider as ambulatory activity is a feasible PA strategy that may lead to several health benefits (eg, improved body composition and mental health) in children with overweight and obesity [43][44][45]. Notably, walking does not require complex movement skills, so it can be performed by most populations, including children with overweight and obesity who frequently do not engage in sports because of their low physical competence [14]. ...
Background:
Best-practice early interventions to increase physical activity (PA) in children with overweight and obesity should be both feasible and evidence based. Walking is a basic human movement pattern that is practical, cost-effective, and does not require complex movement skills. However, there is still a need to investigate how much walking-as a proportion of total PA level-is performed by children who are overweight and obese in order to determine its utility as a public health strategy.
Objective:
This study aimed to (1) investigate the proportion of overall PA indicators that are explained by step-based metrics and (2) study step accumulation patterns relative to achievement of public health recommendations in children who are overweight and obese.
Methods:
A total of 105 overweight and obese children (mean 10.1 years of age [SD 1.1]; 43 girls) wore hip-worn accelerometers for 7 days. PA volumes were derived using the daily average of counts per 15 seconds, categorized using standard cut points for light-moderate-vigorous PA (LMVPA) and moderate-to-vigorous PA (MVPA). Derived step-based metrics included volume (steps/day), time in cadence bands, and peak 1-minute, 30-minute, and 60-minute cadences.
Results:
Steps per day explained 66%, 40%, and 74% of variance for counts per 15 seconds, LMVPA, and MVPA, respectively. The variance explained was increased up to 80%, 92%, and 77% by including specific cadence bands and peak cadences. Children meeting the World Health Organization recommendation of 60 minutes per day of MVPA spent less time at zero cadence and more time in cadence bands representing sporadic movement to brisk walking (ie, 20-119 steps/min) than their less-active peers.
Conclusions:
Step-based metrics, including steps per day and various cadence-based metrics, seem to capture a large proportion of PA for children who are overweight and obese. Given the availability of pedometers, step-based metrics could be useful in discriminating between those children who do or do not achieve MVPA recommendations.
Trial registration:
ClinicalTrials.gov NCT02295072; https://clinicaltrials.gov/ct2/show/NCT02295072.
... 2. It could be assumed that increasing ambulatory activity volume and intensity is a feasible form of PA that can increase the chances of meeting PA recommendations in this population. This is especially important to consider as ambulatory activity is a feasible PA strategy that may lead to several health benefits (eg, improved body composition and mental health) in children with overweight and obesity [43][44][45]. Notably, walking does not require complex movement skills, so it can be performed by most populations, including children with overweight and obesity who frequently do not engage in sports because of their low physical competence [14]. ...
BACKGROUND
Best practice early interventions to increment physical activity in children with overweight/obesity should be both feasible and evidence-based. Walking is a basic human movement pattern that is practical, cost-effective and does not require complex movement skills. However, there is still a need to investigate how much walking is performed by children with overweight/obesity (as proportion of total PA level) in order to determine its utility as a public health strategy.
OBJECTIVE
This study aimed to: 1) investigate the proportion of overall physical activity (PA) indicators that are explained by step-based metrics; and, 2) to study step accumulation patterns relative to achievement of public health recommendations in children with overweight/obesity.
METHODS
One-hundred and five overweight/obese children (10±1 year, 43 girls) were assessed with hip-worn accelerometers for 7 days. Counts/15s were used to derive overall PA indicators (i.e., daily average of counts/15s, light-to-vigorous PA [LMVPA], and moderate-to-vigorous PA [MVPA]). Step-based metrics included volume (steps/day) and intensity (cadence bands and peak 1, 30 and 60-min cadences).
RESULTS
Steps/day explained 66%, 40% and 74% of variance for counts/15s, LMVPA and MVPA, respectively. The variance explained was increased up to 80%, 92% and 77% by including specific cadence bands and peak cadences. Children who achieved the recommended 60 min/day of MVPA spent less time in zero cadence and more time in cadence bands representing sporadic movement to brisk walking (20-120 steps/min) than their less-active peers.
CONCLUSIONS
Step-based metrics, including steps/day and various cadence-based indicators, seem to capture a large proportion of PA for children with overweight/obesity. Given the affordability of pedometers, step-based metrics could be useful for discriminating between those children who do or do not achieve MVPA recommendations.
CLINICALTRIAL
NCT02295072
... Active travel to school (ATS), defining as walking or bicycling to and from school, is associated with multiple benefits among children including higher overall physical activity (Alexander et al., 2005;Cooper et al., 2005;Davison, Werder, & Lawson, 2008;Heelan et al., 2005;Huang, Wong, & He, 2017;Landsberg et al., 2008;Lee, Orenstein, & Richardson, 2008;Sirard et al., 2005), less likely to be obese and to develop chronic disease risk factors (Lubans et al., 2011;Mendoza & Liu, 2014;Pabayo et al., 2010;Pizarro et al., 2013). Also, ATS reduces children's dependence on parents, improves mental health and social interactions, and promotes healthy lifestyles which may be maintained into adulthood (Department of Health U.S. Human Services, 1996;Yang et al., 2014). ...
Background:
Economic growth and urbanization may contribute to the decline of active travel to school (ATS). We aim to explain the change of ATS in China between 1997 and 2011 and to predict the prevalence of ATS in China within the next 30 years using various scenario.
Methods:
We developed a system dynamics model to study ATS and the model assumes the prevalence of ATS is determined by the dynamic interaction of four exogenous and eight endogenous variables.
Results:
The simulated prevalence of ATS is roughly consistent with empirical data. Economic development and urban sprawl are more influential than urban design and crime in terms of ATS. Under a relatively reasonable scenario, the prevalence of ATS is projected to decrease from 73% in 2011 to 65% in 2014, and the prevalence of childhood overweight & obesity is projected to increase from 24% in 2011 to 34% in 2041. With the maintaining of economic development grow, to control urban sprawl is the most effective measure to promote ATS and decrease childhood obesity.
Conclusions:
Overall, the model enabled us to conduct experiments to test the possible effects of changing one or more factors taking into account their dynamic interrelationship, and our study may provide implications for policy intervention.
... Beyond this, little evidence exists linking crime to changes in weight and weight status in children. The six longitudinal studies on U.S. children conducted to date are informative, but have methodological weaknesses limiting their utility for providing clarification in this area (McTigue et al., 2015;Gable et al., 2007;Cecil-Karb & Grogan-Kaylor, 2009;Bacha et al., 2010;Datar et al., 2013;Mendoza & Liu, 2014). All used non-validated parental surveys (four had only one item) that asked about neighborhood safety or markers of crime but not crime itself. ...
Longitudinal studies are warranted to clarify the influence crime has on health outcomes in children especially children representing multiple racial/ethnic backgrounds. To address this need, the current study examined whether neighborhood-level crime predicted changes in body mass index z (BMIz) scores in 373 White (W), 627 African American (AA), 1020 Hispanic (H), and 88 Asian (A), five to ten year-old boys and girls living in urban neighborhoods. Heights and weights were assessed at baseline (2012) and three-years later and used to calculate BMIz scores. Characteristics of zip codes where students lived during the three-year period were obtained at baseline from various sources. The Crime Risk Index (CRI) for each zip code was calculated using actual crime statistics. Multiple linear regression analyses were conducted to examine associations between baseline CRI and follow-up BMIz scores while controlling for other variables including BMIz at baseline. The CRI and BMIz scores differed significantly by race/ethnicity with the highest values for both noted in H. Regression analyses indicated that the CRI accounted for a significant percentage of the variance in follow-up BMIz scores in the overall sample. When race/ethnicity was considered, the CRI predicted follow-up BMIz scores only in W children. The CRI was not significantly associated with BMIz scores in the other races/ethnicities. The impact actual, neighborhood-level crime has on BMI in children is complex. Based on the existing evidence, considering actual crime as a primary target in obesity prevention would be premature especially in racial/ethnicity minority children living in urban areas.
... Social inequities were notably highlighted in studies reporting higher rates of active transportation in neighbourhoods perceived by parents as being unsafe 55 or not an "excellent" area for raising a child. 56 Cutumisu et al. 57 also reported that children living in neighbourhoods with higher material (i.e., low education, employment and income) and social (i.e., single-parent households) deprivation were much more likely to engage in active transportation to school. ...
... Pelbagai jenis intervensi dan kajian penyelidikan dilaksanakan hingga sekarang dalam memastikan kadar mobilisasi aktif pelajar ke sekolah terus meningkat. Asas kepada intervensi dan kajian penyelidikan yang berterusan adalah berdasarkan kepada dapatan kajian yang menunjukkan kelebihan aktiviti fizikal aktif pelajar dari rumah ke sekolah seperti dapat meningkatkan aktiviti fizikal harian [6], mengurangkan indeks jisim badan [15], memperbaiki tahap kesihatan kardio vascular, mengurangkan stress [12], dan menurunkan kadar obesiti [7]. Selain itu, dapatan kajian lepas turut menunjukkan bahawa kebergantungan pelajar dengan menaiki kenderaan dari rumah hingga ke pintu pagar sekolah akan menyebabkan kesesakan lalu lintas dan penurunan tahap kualiti udara [4]. ...
Kertas konsep ini adalah untuk membincangkan impak kerjasama strategik dalam agensi kerajaan dalam menjayakan perancangan mobilisasi aktif pelajar ke sekolah. Dapatan kajian-kajian lepas menunjukkan aktiviti pelajar aktif ke sekolah mampu meningkatkan tahap kesihatan pelajar, mengurangkan kesesakan lalu lintas dan memperbaiki tahap kualiti udara. Analisis kajian mobilisasi aktif pelajar ke sekolah di New Zealand dan Kanada menemukan model perancangan yang dilaksanakan menerusi pembentukan dokumen School Travel Plan dan faktor-faktor yang mempengaruhi keberkesanan perancangan. Dapatan daripada analisis kajian berkenaan dibawa kepada perbincangan bagi mencadangkan program Perancangan Pelajar Aktif, Cergas dan Unggul (PACU) ke Sekolah untuk dilaksanakan di Malaysia. Kajian-kajian rintis dan lanjutan perlu untuk dilakukan bagi memastikan program Perancangan PACU ke Sekolah sentiasa menyokong dan memenuhi keperluan dasar-dasar semasa pembangunan negara.
... In 1969, 47.7% of U.S. children in kindergarten (K) through eighth grade regularly traveled by ACS versus 12.7% in 2009. 1 This drop in ACS represents a loss of a daily source of physical activity that may contribute to age-related drops in physical activity and the childhood obesity epidemic. [2][3][4] Greater ACS was associated with greater moderate-to-vigorous physical activity (MVPA), lower BMI z-score, and lower blood pressure [5][6][7][8][9][10][11][12][13] ; however, most studies were observational or focused exclusively on walking to school. The rate of cycling to school in the U.S. is only 1% for K-eighth graders, 1 and several studies suggest low-income children's percentage of cycling to school is even lower. ...
Introduction:
Increasing children's cycling to school and physical activity are national health goals. The objective was to conduct an RCT of a bicycle train program to assess impact on students' school travel mode and moderate-to-vigorous physical activity (MVPA).
Study design:
Pilot cluster RCT with randomization at the school level and N=54 participants.
Setting/participants:
Fourth-fifth graders from four public schools serving low-income families in Seattle, WA in 2014 with analyses in 2015-2016. All participants were provided and fitted with bicycles, safety equipment (helmets, locks, and lights), and a 2- to 3-hour bicycle safety course.
Intervention:
The intervention was a bicycle train offered daily (i.e., students volunteered to cycle with study staff to and from school).
Main outcome measures:
Time 1 assessments occurred prior to randomization. Time 2 assessments occurred after 3-5 weeks of the intervention (i.e., during Weeks 4-6 of the intervention period). The primary outcome was the percentage of daily commutes to school by cycling measured by validated survey. MVPA, measured by accelerometry and GPS units and processed by machine learning algorithms, was a secondary outcome.
Results:
For two separate adjusted repeated measures linear mixed effects models in which students (N=54) were nested within schools (N=4), intervention participants had: (1) an absolute increase in mean percentage of daily commutes by cycling of 44.9%, (95% CI=26.8, 63.0) and (2) an increase in mean MVPA of 21.6 minutes/day, (95% CI=8.7, 34.6) from Time 1 to Time 2 compared with controls.
Conclusions:
A pilot bicycle train intervention increased cycling to school and daily MVPA in the short term among diverse, inner-city elementary school students. The bicycle train intervention appears promising and warrants further experimental trials among large, diverse samples with longer follow-up.
Trial registration:
This study is registered at www.clinicaltrials.gov NCT02006186.
... On the other hand, recent findings also suggest that body mass index percentiles in school students are associated with metabolic syndrome risk score independently of screen and leisure time activity [118]. Examining a representative sample of kindergarten students, it has been demonstrated that children who engaged in walking or biking to school had lower BMI scores than passive commuters [119]. Of interest, reduced television viewing and low levels of physical activity during adolescence predicted the metabolic syndrome in mid-adulthood [120] and higher lev- els of cardio respiratory fitness substantially decrease the risk of adult metabolic syndrome, even among those with abdominal obe- sity in childhood [121]. ...
In the last decades the increasing rate of obesity in children and adolescent worldwide has led to the onset in paediatric age of metabolic syndrome a disease commonly associated to adulthood. Central obesity, dyslipidaemia, hyperglycaemia, and hypertension are typical features of metabolic syndrome that seem to hesitate often in type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and many other clinical conditions. Thus preventing and curing metabolic syndrome in paediatric patients is becoming an urgent need for public health. While diagnostic criteria and therapy of metabolic syndrome in adults are very well defined, there is no consensus on the definition of metabolic syndrome in children and adolescents as well as on healing approaches. The aim of this review is to describe the recent advances on the pathogenesis and clinical outcomes of paediatric metabolic syndrome. We then detail the therapeutic strategies (i.e. dietary regimens, physical exercise, nutraceuticals, and medications) employed to manage the disease. Finally, we analyse the safety profile of the drugs used in children and adolescents by performing a retrospective review of paediatric adverse reactions reported in the FDA's Adverse Event Reporting System database.
... Interestingly, almost 30 % of children in this study live within 1.5 km of the school yet do not commute to school actively. Active commuting to school and to other activities is associated with improved health [100], fitness [101][102][103] and energy balance [104,105], and serves as a valuable opportunity for children to significantly increase daily physical activity levels [106][107][108]. Increasing children's and parents awareness of the various forms of physical activity such as active travel and unstructured play, and how these contribute to children achieving daily physical activity recommendations is warranted. ...
Background: Research to increase children’s physical activity and inform intervention design has, to date, largely underrepresented children’s voices. Further, research has been limited to singular qualitative methods that overlook children’s varied linguistic ability and interaction preference. The aim of this study was to use a novel combination of qualitative techniques to explore children’s current views, experiences and perceptions of out-of-school physical activity as well as offering formative opinion about future intervention design.
Methods: Write, draw, show and tell (WDST) groups were conducted with 35 children aged 10–11 years from 7 primary schools. Data were analysed through a deductive and inductive process, firstly using the Youth Physical Activity Promotion Model as a thematic framework, and then inductively to enable emergent themes to be further explored. Pen profiles were constructed representing key emergent themes.
Results: The WDST combination of qualitative techniques generated complimentary interconnected data which both confirmed and uncovered new insights into factors relevant to children’s out-of-school physical activity. Physical activity was most frequently associated with organised sports. Fun, enjoyment, competence, and physical activity provision were all important predictors of children’s out-of-school physical activity. Paradoxically, parents served as both significant enablers (i.e. encouragement) and barriers (i.e. restricting participation) to physical activity participation. Some of these key findings would have otherwise remained hidden when compared to more traditional singular methods based approaches.
Conclusions: Parents are in a unique position to promote health promoting behaviours serving as role models, physical activity gatekeepers and choice architects. Given the strong socialising effect parents have on children’s physical activity, family-based physical activity intervention may offer a promising alternative compared to traditional school-based approaches. Parents' qualitative input is important to supplement children’s voices and inform future family-based intervention design. The WDST method developed here is an inclusive, interactive and child-centred methodology which facilitates the exploration of a wide range of topics and enhances data credibility.
... Researchers have almost exclusively examined trips that are entirely walk-or bike-based, especially those connected to trips to or from school. [3][4][5][6][7][8][9][10][11] Unfortunately, this emphasis on school-related trips using selected transport modes neglects the fact that children frequently travel to nonschool destinations, and it does not properly account for public transit use among children. Public transit (eg, bus, light rail, subway, etc) lies in the middle of the active versus motorized travel mode continuum. ...
Background:
The potential for adults to accrue significant physical activity through public transit use is a topic of interest. However, there are no data on analogous questions among children. The goal of this analysis was to quantify patterns of transit use and correlates of transit-related physical activity among children aged 5 to 17 years.
Methods:
Data for this cross-sectional study came from the 2012 California Household Travel Survey. Probit regressions modeled the probability of transit use; negative binomial regressions modeled minutes/day in transit-related active travel.
Results:
Public transit use accounted for 3% of trips in California in 2012. Older, Hispanic youth, and those residing in areas with greater housing density and county size had a higher probability of transit use. Driver licensure, home ownership, household income, and vehicles in household were negatively correlated with public transit use. Race/ethnicity, income, and transit type were correlated with time spent in active travel to/from transit.
Conclusions:
Given its importance as a source of physical activity for some children, researchers should consider assessment of public transit-related activity in physical activity measurement instruments. Efforts to encourage active travel should consider how to incorporate transit-related activity, both from a measurement perspective and as an intervention strategy.
... Data from Stabelini-Neto et al. [15] indicate that achieving approximately 90 min per day of moderate-to-vigorous physical activity will likely prevent development of the MetS in adolescents. Mendoza and Liu [16] examined a nationally representative sample of US kindergarten students and found that children who engaged in active transport to school (walking or biking) in kindergarten had lower BMI zscores in fifth grade than their peers who were passive commuters to school. Lazorick et al. [17••] reported the results of a longitudinal obesity prevention intervention targeting a single-site cohort of 106 students beginning in seventh grade and followed across 5 years. ...
Although research published during the past year suggests the prevalence of childhood obesity in the USA may have plateaued, it remains unacceptably high and places large numbers of youths at elevated risk of chronic diseases. The concept of the metabolic syndrome (MetS) is frequently used to help capture this increased risk. Use of the MetS concept with children remains controversial, however. Addressing issues related to the definition of the MetS and its utility in clinical and research settings has generated a variety of recent investigative efforts. At the same time, the past year revealed a number of promising prevention and treatment interventions for childhood obesity and the MetS. Still unknown, however, is the optimal combination of diet, exercise, and other behavioral changes for improving the obesity and MetS status of children. These issues are the subject of this review.
... Notably, children were more likely to engage in AST if school principals perceived that crime was a major or moderate problem in the school neighbourhood. While counter-intuitive, this finding is in agreement with previous research reporting a greater likelihood of AST if parents did not perceive their neighbourhood as safe [34] or as an excellent area to raise a child [35]. Other researchers also reported higher rates of AST in areas characterized by greater incivilities [36]. ...
Background
Active school transport (AST) is an important source of children’s daily physical activity (PA). However, decreasing rates of AST have been reported in multiple countries during the last decades. The purpose of the present study was to examine the socio-demographic and school-level correlates of AST.
Methods
A stratified sample of children (N = 567, mean age = 10.0 years; 57.8% female) was recruited in the Ottawa area. Four sources of data were used for analyses: 1) child questionnaire including questions on school travel mode and time; 2) parent questionnaire providing information on household socio-demographic characteristics; 3) school administrator survey assessing school policies and practices pertaining to PA; and 4) school site audit performed by the study team. Generalized linear mixed models were used to identify socio-demographic and school-level correlates of AST while controlling for school clustering.
Results
Individual factors associated with higher odds of AST were male gender (OR = 1.99; 95% CI = 1.30-3.03), journey time <5 minutes vs. >15 minutes (OR = 2.26; 95% CI = 1.17-4.37), and 5–15 minutes vs. >15 minutes (OR = 2.27; 95% CI = 1.27-4.03). Children were more likely to engage in AST if school administrators reported that crossing guards were employed (OR = 2.29; 95% CI = 1.22-4.30), or if they expressed major or moderate concerns about crime in the school neighbourhood (OR = 3.34; 95% CI = 1.34-8.32). In schools that identified safe routes to school and where traffic calming measures were observed, children were much more likely to engage in AST compared to schools without these features (OR = 7.87; 95% CI = 2.85-21.76). Moreover, if only one of these features was present, this was not associated with an increased likelihood of AST.
Conclusion
These findings suggest that providing crossing guards may facilitate AST. Additionally, there was a synergy between the identification of safe routes to school and the presence of traffic calming measures, suggesting that these strategies should be used in combination.
Introduction
Adolescents' physical activity (PA) and commuting behaviors are related to their parents' perceptions of the neighborhood. This study analyzed the association between parental reasons for choosing a neighborhood to live in and their adolescent’ moderate-to-vigorous PA (MVPA), active commuting to/from school (ACS), and independent mobility (IM) excluding school travel.
Methods
Participants were adolescents (n = 373) and their parents (n = 373) in Spain. Parents reported their reasons for choosing a neighborhood, and adolescents reported their ACS and IM excluding school travel. Accelerometry was used to assess adolescents’ MVPA. Multilevel regressions were used to analyze the associations between parental reasons and the outcome variables (MVPA, ACS and IM).
Results
High importance of affordability/value for parents was associated with higher levels of weekday MVPA in adolescents (β = 2.17, 95% confidence interval [CI] 0.21, 4.16), whereas greater distance from busy streets (β = 2.08, 95% CI 0.12, 4.51) was positively associated with MVPA during the weekend. A higher percentage of ACS in adolescents was associated with having parents who valued proximity to the school (β = 3.43, 95% CI 0.17, 0.64). IM excluding school travel was higher when parents assigned relatively less value to the proximity of the school (β = −3.35, 95% CI −8.76, −2.28), safety from crime (β = −2.77, 95% CI −6.63, −1.39), and sense of community (β = −2.31, 95% CI −6.63, −0.53).
Conclusions
It is crucial to develop spaces and facilities for PA, and to increase the walkability of the neighborhoods, considering the distance from home to school, in order to promote MVPA and ACS in adolescents.
Objectives
Active travel to school (ATS)-associated factors had been studied in some developed countries but rarely in China. We studied the associated factors of ATS at individual, parental and built environment domains in northeast China.
Design and participants
A cross-sectional survey was conducted among 4–6 grade students in 2017. Sociodemographic features and information of parents were collected using questionnaires, and SuperMap (a geographical information system software) was used to catch built environment features. Logistic regression models were used to examine the relationship between multilevel factors and ATS.
Results
Our study sample comprised 3670 primary school students aged from 8 to 15 (boys=51.0%, ATS=48.8%). Perceived to be fat (OR 1.25, 95% CI 1.00 to 1.55, p<0.05), feeling easy to walk for a short distance (OR 1.63, 95% CI 1.21 to 2.20, p<0.05), mother unemployed (OR 1.52, 95% CI 1.13 to 2.06, p<0.05), higher land use mix (OR 1.23, 95% CI 1.11 to 1.37, p<0.001) and higher density of public transport stations (OR 1.22, 95% CI 1.09 to 1.37, p<0.05) were positively associated with increased possibility of ATS, while higher household annual income (OR 0.60, 95% CI 0.44 to 0.83, p<0.05) and possession of private vehicles (OR 0.56, 95% CI 0.45 to 0.69, p<0.001) were negatively associated with possibility of ATS.
Conclusions
The significant factors associated with ATS were at every examined level, which implies multilevel interventions are needed to encourage ATS. Further interventions could focus on the children’s willingness to lead students to opt for healthy behaviours, and children from wealthier families should be encouraged to choose ATS. Also, the government should improve built environment walkability so as to encourage ATS.
This paper explores the relationship between the school and the local community in Norway from the beginning of compulsory schooling early in the 18th century to the present day globalised context. This historical overview focuses on three main points. First, how the political struggle for an equitable education provision during the first half of the 20th century gradually resulted in rural schooling approaching the urban version as to school size and content. Second, how popular mobilisation against extensive school centralisation, new research on the functioning of small schools, and new perspectives on learning, knowledge and sociology of education during the 1960s and 1970s paved the way for rural schools to actually be able to serve rural pupils and rural communities. Third, how since the 1980s, various aspects of globalisation have impacted on rural education provision in ways which makes it less responsive to the specific conditions of rural communities.
Background:
Active commuting to school (ACS) is associated with increased physical activity and lowered risk of obesity. In observational studies, ACS was associated with child self-efficacy, parent self-efficacy, and parent outcome expectations, although few experiments have assessed changes in these behavioral constructs.
Aim:
This study examined the effects of a bicycle train intervention (BTI) on child self-efficacy, parent self-efficacy, and parent outcome expectations in a diverse, low socioeconomic status population.
Method:
Data were from a 2014 BTI pilot randomized controlled trial (RCT) on fourth to fifth graders aged 9 to 12 years, n = 54, from four schools serving low-income populations in Seattle, Washington. The BTI was a group of children and study staff who cycled together to/from school daily, while controls received no intervention. Responses to validated child self-efficacy, parent self-efficacy, and parent outcome expectations questionnaires ranged from 1 to 3. Adjusted linear mixed effects models estimated standardized coefficients for child self-efficacy, parent self-efficacy, and parent outcome expectations comparing intervention and controls from Time 1 (preintervention) to Time 2 (final 4-6 weeks of intervention).
Results:
The intervention group had increases in child self-efficacy of 0.84 standard deviations (95% confidence interval [CI] [0.37, 1.31]), parent self-efficacy of 0.46 standard deviations (95% CI [0.05, 0.86]), and parent outcome expectations of 0.47 standard deviations (95% CI [0.17, 0.76]) compared with controls from Times 1 to 2 (all ps <.05).
Conclusion:
A BTI improved child self-efficacy, parent self-efficacy, and parent outcome expectations, which warrants a larger RCT to examine long-term changes to these behavioral constructs and ACS.
Increasing rates of body weight of children has become a motivation for investigating active transportation to school during the past years. Lack of proper data covering different geographical contexts is a problem seen in the literature of this subject. The present paper reports the findings of a recent survey on nine cities in seven European countries funded by the European Commission. The objective of the survey was to provide data covering several topics in relation with active commuting to school and body mass index, such as parental perceptions of safety and security, neighborhood facilities, land use characteristics, etc. in different regions of Europe in a way that cross-sectional comparisons between regions and city sizes is facilitated. For that, 2735 children/parents were handed out questionnaires, from whom 1424 filled out the questionnaires (response rate: 52%). This led to 1304 validated questionnaires. The respondents studied in 21 elementary schools of Foggia, Italy; Berlin, Germany; Thessaloniki, Greece; Rijeka, Croatia; Utrecht, The Netherlands; Łódź, Poland; Konstantynow, Poland; Malatya, Turkey, and Doğanşehir, Turkey as of March 2016 until January 2017. The survey instrument enables development of continuous and categorical variables for empirical research with strong focus on the built environment using the aggregate data provided by this study. It is expected that the output data eases production of knowledge about less-studied European contexts as well as cross-sectional comparison of results with more studied areas of Western Europe.
Unsafe residential neighbourhoods are thought to be a risk factor for childhood obesity by discouraging physical activity while encouraging sedentary behaviours, but findings from cross-sectional studies are susceptible to selection bias (e.g. children who are obese disproportionately reside in unsafe neighbourhoods). A literature search was conducted in the Cochrane Library, PubMed, Web of Science and Google Scholar for articles published until January 2017 that used baseline neighbourhood safety levels to predict future weight-related behaviours and body-weight status among children aged 17 years and younger. Twenty-two prospective cohort studies conducted in seven countries were identified. The median sample size was 1,104, and the median follow-up was 3.5 years. Sixteen studies used parent-reported and/or child-reported neighbourhood safety measures, and six adopted some objective measures (e.g. county crime rate and interviewers' block observations). The meta-analysis found that living in unsafe neighbourhoods was associated with a reduction in children's physical activity by 0.13 h week(-1) . Living in unsafe neighbourhoods predicted a trivial (but statistically significant) gain in body mass index but no change in childhood overweight/obesity risk. Current research indicates a limited influence of neighbourhood safety on childhood obesity; this finding could be partially due to measurement problems. Future longitudinal studies should adopt validated neighbourhood safety measures.
The objective of this study was to identify facilitators and barriers to effective School Travel Planning (STP) implementation.
Insufficient levels of daily physical activity (PA) among children in the USA and worldwide have profound implications for pediatric obesity and children's health and well-being more generally. Public health recommendations highlight the central role that schools play in providing equitable opportunities for PA for all children. This review identifies evidence-based approaches for increasing children's PA throughout the school day and discusses multilevel factors that support implementation of such approaches. Opportunities to increase school-day PA span not only in-school time (e.g., quality recess and physical education, classroom activity breaks) but also time before school (e.g., active commuting initiatives) and after school (e.g., intramural and interscholastic sports programs). For such approaches to impact children's PA, dimensions of implementation such as adoption, fidelity, penetration, implementation costs, and sustainability are critical. Multilevel factors that influence implementation include policies, school environment and organizational factors, teacher and classroom factors, child and family characteristics, and attributes of the PA approach itself. Research and field observations reinforce the importance of understanding challenges specific to working with schools, including multiple stakeholders, competing priorities, limited facilities and staff capacity, and heterogeneity of students. Thus, while schools hold promise as promoters and equalizers of PA engagement for all children, more research is needed on the levers that influence implementation of effective school-based PA policies and programs.
Introduction:
Driven largely by international declines in rates of walking and bicycling to school and the noted health benefits of physical activity for children, research on children's active commuting to school has expanded rapidly during the past 5 years. We summarize research on predictors and health consequences of active commuting to school and outline and evaluate programs specific to children's walking and bicycling to school.
Methods:
Literature on children's active commuting to school published before June 2007 was compiled by searching PubMed, PsycINFO, and the National Transportation Library databases; conducting Internet searches on program-based activities; and reviewing relevant transportation journals published during the last 4 years.
Results:
Children who walk or bicycle to school have higher daily levels of physical activity and better cardiovascular fitness than do children who do not actively commute to school. A wide range of predictors of children's active commuting behaviors was identified, including demographic factors, individual and family factors, school factors (including the immediate area surrounding schools), and social and physical environmental factors. Safe Routes to School and the Walking School Bus are 2 public health efforts that promote walking and bicycling to school. Although evaluations of these programs are limited, evidence exists that these activities are viewed positively by key stakeholders and have positive effects on children's active commuting to school.
Conclusion:
Future efforts to promote walking and bicycling to school will be facilitated by building on current research, combining the strengths of scientific rigor with the predesign and postdesign provided by intervention activities, and disseminating results broadly and rapidly.
Background:
In 2005, the US Congress allocated $612 million for a national Safe Routes to School (SRTS) program to encourage walking and bicycling to schools. We analyzed motor vehicle crash data to assess the effectiveness of SRTS interventions in reducing school-aged pedestrian injury in New York City.
Methods:
Using geocoded motor vehicle crash data for 168 806 pedestrian injuries in New York City between 2001 and 2010, annual pedestrian injury rates per 10 000 population were calculated for different age groups and for census tracts with and without SRTS interventions during school-travel hours (defined as 7 am to 9 am and 2 pm to 4 pm, Monday through Friday during September through June).
Results:
During the study period, the annual rate of pedestrian injury decreased 33% (95% confidence interval [CI]: 30 to 36) among school-aged children (5- to 19-year-olds) and 14% (95% CI: 12 to 16) in other age groups. The annual rate of school-aged pedestrian injury during school-travel hours decreased 44% (95% CI: 17 to 65) from 8.0 injuries per 10 000 population in the preintervention period (2001-2008) to 4.4 injuries per 10 000 population in the postintervention period (2009-2010) in census tracts with SRTS interventions. The rate remained virtually unchanged in census tracts without SRTS interventions (0% [95% CI: -8 to 8]).
Conclusions:
Implementation of the SRTS program in New York City has contributed to a marked reduction in pedestrian injury in school-aged children.
Childhood obesity predisposes to adult obesity and increases the risk of many diseases. Schools provide a vehicle to deliver public health interventions to all children.
Medline and Embase were used to undertake a systematic review of published studies of school-based interventions aimed at reducing the body mass index (BMI) of children ≤ 18 years. Preferred reporting items for systematic reviews and meta-analyses guidelines were followed, and eligible studies subjected to a random effects meta-analysis.
Between 1991 and 2010, 43 published studies provided 60 measurements of effect. The pooled effect was a 0.17 (95% CI: 0.08, 0.26, P < 0.001) reduction in BMI. Heterogeneity was high (I(2) = 93.4%) but there was no significant small study bias (Egger's test, P = 0.422) nor significant variation by length of follow-up. The intervention comprised physical activity only in 11 (26%) studies, education only in three (7%), and combinations of these and improved nutrition in the remaining 29 (67%). On stratified analysis, physical activity used in isolation (-0.13, 95% CI: -0.22, -0.04, P = 0.001) or combined with improved nutrition (-0.17, 95% CI: -0.29, -0.06, P < 0.001) was associated with significant improvements in BMI. Interventions targeted at overweight/obese children reduced their BMI by 0.35 (95% CI: 0.12, 0.58, P = 0.003). Those delivered to all children reduced it by 0.16 (95% CI: 0.06, 0.25, P = 0.002).
There is growing evidence that school-based interventions that contain a physical activity component may be effective in helping to reduce BMI in children.
The prevalence of childhood obesity increased in the 1980s and 1990s but there were no significant changes in prevalence between 1999-2000 and 2007-2008 in the United States.
To present the most recent estimates of obesity prevalence in US children and adolescents for 2009-2010 and to investigate trends in obesity prevalence and body mass index (BMI) among children and adolescents between 1999-2000 and 2009-2010.
Cross-sectional analyses of a representative sample (N = 4111) of the US child and adolescent population (birth through 19 years of age) with measured heights and weights from the National Health and Nutrition Examination Survey 2009-2010.
Prevalence of high weight-for-recumbent length (≥95th percentile on the growth charts) among infants and toddlers from birth to 2 years of age and obesity (BMI ≥95th percentile of the BMI-for-age growth charts) among children and adolescents aged 2 through 19 years. Analyses of trends in obesity by sex and race/ethnicity, and analyses of trends in BMI within sex-specific age groups for 6 survey periods (1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, and 2009-2010) over 12 years.
In 2009-2010, 9.7% (95% CI, 7.6%-12.3%) of infants and toddlers had a high weight-for-recumbent length and 16.9% (95% CI, 15.4%-18.4%) of children and adolescents from 2 through 19 years of age were obese. There was no difference in obesity prevalence among males (P = .62) or females (P = .65) between 2007-2008 and 2009-2010. However, trend analyses over a 12-year period indicated a significant increase in obesity prevalence between 1999-2000 and 2009-2010 in males aged 2 through 19 years (odds ratio, 1.05; 95% CI, 1.01-1.10) but not in females (odds ratio, 1.02; 95% CI, 0.98-1.07) per 2-year survey cycle. There was a significant increase in BMI among adolescent males aged 12 through 19 years (P = .04) but not among any other age group or among females.
In 2009-2010, the prevalence of obesity in children and adolescents was 16.9%; this was not changed compared with 2007-2008.
Walking school buses (WSB) increased children's physical activity, but impact on pedestrian safety behaviors (PSB) is unknown. We tested the feasibility of a protocol evaluating changes to PSB during a WSB program. Outcomes were school-level street crossing PSB prior to (Time 1) and during weeks 4-5 (Time 2) of the WSB. The protocol collected 1252 observations at Time 1 and 2548 at Time 2. Mixed model analyses yielded: intervention schoolchildren had 5-fold higher odds (p<0.01) of crossing at the corner/crosswalk but 5-fold lower odds (p<0.01) of stopping at the curb. The protocol appears feasible for documenting changes to school-level PSB.
To evaluate the impact of a "walking school bus" program on children's rates of active commuting to school and physical activity.
We conducted a pilot cluster randomized controlled trial among 4th-graders from 8 schools in Houston, Texas (N = 149). Random allocation to treatment or control conditions was at the school level. Study staff walked with children to and from school up to 5 days/week. Outcomes were measured the week before (time 1) and during weeks 4 and 5 of the intervention (time 2). The main outcome was the weekly rate of active commuting, and a secondary outcome was moderate-to-vigorous physical activity. Covariates included sociodemographics, distance from home to school, neighborhood safety, child BMI z score, parent self-efficacy/outcome expectations, and child self-efficacy for active commuting. A mixed-model repeated measures regression accounted for clustering by school, and stepwise procedures with backward elimination of nonsignificant covariates were used to identify significant predictors.
Intervention children increased active commuting (mean ± SD) from 23.8% ± 9.2% (time 1) to 54% ± 9.2% (time 2), whereas control subjects decreased from 40.2% ± 8.9% (time 1) to 32.6% ± 8.9% (time 2) (P < .0001). Intervention children increased their minutes of daily moderate-to-vigorous physical activity from 46.6 ± 4.5 (time 1) to 48.8 ± 4.5 (time 2), whereas control children decreased from 46.1 ± 4.3 (time 1) to 41.3 ± 4.3 (time 2) (P = .029).
The program improved children's active commuting to school and daily moderate-to-vigorous physical activity.
The purpose of this study is to assess the reliability and validity of the U.S. National Center for Safe Routes to School's in-class student travel tallies and written parent surveys. Over 65,000 tallies and 374,000 parent surveys have been completed, but no published studies have examined their measurement properties.
Students and parents from two Charlotte, NC (USA) elementary schools participated. Tallies were conducted on two consecutive days using a hand-raising protocol; on day two students were also asked to recall the previous days' travel. The recall from day two was compared with day one to assess 24-hour test-retest reliability. Convergent validity was assessed by comparing parent-reports of students' travel mode with student-reports of travel mode. Two-week test-retest reliability of the parent survey was assessed by comparing within-parent responses. Reliability and validity were assessed using kappa statistics.
A total of 542 students participated in the in-class student travel tally reliability assessment and 262 parent-student dyads participated in the validity assessment. Reliability was high for travel to and from school (kappa > 0.8); convergent validity was lower but still high (kappa > 0.75). There were no differences by student grade level. Two-week test-retest reliability of the parent survey (n=112) ranged from moderate to very high for objective questions on travel mode and travel times (kappa range: 0.62-0.97) but was substantially lower for subjective assessments of barriers to walking to school (kappa range: 0.31-0.76).
The student in-class student travel tally exhibited high reliability and validity at all elementary grades. The parent survey had high reliability on questions related to student travel mode, but lower reliability for attitudinal questions identifying barriers to walking to school. Parent survey design should be improved so that responses clearly indicate issues that influence parental decision making in regards to their children's mode of travel to school.
Walking or bicycling to school (ie, active commuting) has shown promise for improving physical activity and preventing obesity in youth. Our objectives were to examine, among US youth, whether active commuting was inversely associated with adiposity and positively associated with moderate-to-vigorous physical activity (MVPA). We also examined whether MVPA mediated the relationships between active commuting and adiposity.
Using data of participants aged 12 to 19 years from the US National Health and Nutrition Examination Survey 2003 to 2004 (n=789 unweighted), we constructed multiple linear regression models that controlled for dietary energy intake and sociodemographics. The main exposure variable was active commuting. The outcomes were BMI z-score, waist circumference, skinfolds and objectively measured MVPA. The product-of-coefficients method was used to test for mediation.
Active commuting was inversely associated with BMI z-score (β=-0.07, P=.046) and skinfolds (β=-0.06, P=.029), and positively associated with overall daily (β=0.12, P=.024) and before- and after-school (β=0.20, P<.001) MVPA. Greater before- and after-school MVPA explained part of the relationship between active commuting and waist circumference (Sobel z=-1.98, P=.048).
Active commuting was associated with greater MVPA and lower measures of adiposity among US youth. Before- and after-school MVPA mediated the relationships between active commuting and waist circumference.
Increased physical activity levels benefit both an individuals' health and productivity at work. The purpose of the current study was to explore the impact and cost-effectiveness of a workplace physical activity intervention designed to increase physical activity levels.
A total of 1260 participants from 44 UK worksites (based within 5 organizations) were recruited to a cluster randomized controlled trial with worksites randomly allocated to an intervention or control condition. Measurement of physical activity and other variables occurred at baseline, and at 0 months, 3 months and 9 months post-intervention. Health outcomes were measured during a 30 minute health check conducted in worksites at baseline and 9 months post intervention. The intervention consisted of a 3 month tool-kit of activities targeting components of the Theory of Planned Behavior, delivered in-house by nominated facilitators. Self-reported physical activity (measured using the IPAQ short-form) and health outcomes were assessed.
Multilevel modelling found no significant effect of the intervention on MET minutes of activity (from the IPAQ) at any of the follow-up time points controlling for baseline activity. However, the intervention did significantly reduce systolic blood pressure (B=-1.79 mm/Hg) and resting heart rate (B=-2.08 beats) and significantly increased body mass index (B=.18 units) compared to control. The intervention was found not to be cost-effective, however the substantial variability round this estimate suggested that further research is warranted.
The current study found mixed support for this worksite physical activity intervention. The paper discusses some of the tensions involved in conducting rigorous evaluations of large-scale randomized controlled trials in real-world settings.
Active transportation to school is an important contributor to the total physical activity of children and adolescents. However, active school travel has declined over time, and interventions are needed to reverse this trend. The purpose of this paper is to review intervention studies related to active school transportation to guide future intervention research.
A systematic review was conducted to identify intervention studies of active transportation to school published in the scientific literature through January 2010. Five electronic databases and a manual search were conducted. Detailed information was extracted, including a quantitative assessment comparing the effect sizes, and a qualitative assessment using an established evaluation tool.
We identified 14 interventions that focused on active transportation to school. These interventions mainly focused on primary school children in the United States, Australia, and the United Kingdom. Almost all the interventions used quasi-experimental designs (10/14), and most of the interventions reported a small effect size on active transportation (6/14).
More research with higher quality study designs and measures should be conducted to further evaluate interventions and to determine the most successful strategies for increasing active transportation to school.
Active travel to school (ATS) has been identified as an important source of physical activity for youth. However, the relationship between ATS and health-related fitness (HRF) among youth remains unclear.
A systematic search of seven electronic databases (EMBASE, OVID MEDLINE, PsycINFO, PubMed, Scopus, SPORTDiscus and TRIS on line) was conducted in December 2009 and studies published since 1980 were considered for inclusion.
Twenty seven articles were identified that explored the relationship between ATS and the following aspects of HRF: weight status/body composition, cardiorespiratory fitness, muscular fitness and flexibility. Forty-eight percent of the studies that examined the relationship between ATS and weight status/body composition reported significant associations, this increased to 55% once poor quality studies were removed. Furthermore, the findings from five studies, including one longitudinal study, indicate that ATS is positively associated with cardiorespiratory fitness in youth. However, the evidence for the relationships between ATS and muscular fitness or flexibility is equivocal and limited by low study numbers.
There is some evidence to suggest that ATS is associated with a healthier body composition and level of cardiorespiratory fitness among youth. Strategies to increase ATS are warranted and should be included in whole-of-school approaches to the promotion of physical activity.
The assessment of physical activity is an essential part of understanding patterns and influences of behaviour, designing interventions, and undertaking population surveillance and monitoring, but it is particularly problematic when using self-report instruments with young people. This study reviewed available self-report physical activity instruments developed for use with children and adolescents to assess their suitability and feasibility for use in population surveillance systems, particularly in Europe.
Systematic searches and review, supplemented by expert panel assessment.
Papers (n=437) were assessed as potentially relevant; 89 physical activity measures were identified with 20 activity-based measures receiving detailed assessment. Three received support from the majority of the expert group: Physical Activity Questionnaire for Children/Adolescents (PAQ-C/PAQ-A), Youth Risk Behaviour Surveillance Survey (YRBS), and the Teen Health Survey.
Population surveillance of youth physical activity is strongly recommended and those involved in developing and undertaking this task should consider the three identified shortlisted instruments and evaluate their appropriateness for application within their national context. Further development and testing of measures suitable for population surveillance with young people is required.
Safe Routes to School (SRTS) programs are designed to make walking and bicycling to school safe and accessible for children. Despite their growing popularity, few validated measures exist for assessing important outcomes such as type of student transport or pedestrian safety behaviors. This research validated the SRTS school travel survey and a pedestrian safety behavior checklist.
Fourth grade students completed a brief written survey on how they got to school that day with set responses. Test-retest reliability was obtained 3-4 hours apart. Convergent validity of the SRTS travel survey was assessed by comparison to parents' report. For the measure of pedestrian safety behavior, 10 research assistants observed 29 students at a school intersection for completion of 8 selected pedestrian safety behaviors. Reliability was determined in two ways: correlations between the research assistants' ratings to that of the Principal Investigator (PI) and intraclass correlations (ICC) across research assistant ratings.
The SRTS travel survey had high test-retest reliability (kappa = 0.97, n = 96, p < 0.001) and convergent validity (kappa = 0.87, n = 81, p < 0.001). The pedestrian safety behavior checklist had moderate reliability across research assistants' ratings (ICC = 0.48) and moderate correlation with the PI (r = 0.55, p = < 0.01). When two raters simultaneously used the instrument, the ICC increased to 0.65. Overall percent agreement (91%), sensitivity (85%) and specificity (83%) were acceptable.
These validated instruments can be used to assess SRTS programs. The pedestrian safety behavior checklist may benefit from further formative work.
To evaluate the impact of a walking school bus (WSB) program on student transport in a low-income, urban neighborhood.
The design was a controlled, quasi-experimental trial with consecutive cross-sectional assessments. The setting was three urban, socioeconomically disadvantaged, public elementary schools (1 intervention vs. 2 controls) in Seattle, Washington, USA. Participants were ethnically diverse students in kindergarten-5th grade (aged 5-11 years). The intervention was a WSB program consisting of a part-time WSB coordinator and parent volunteers. Students' method of transportation to school was assessed by a classroom survey at baseline and one-year follow-up. The Pearson Chi-squared test compared students transported to school at the intervention versus control schools at each time point. Due to multiple testing, we calculated adjusted p-values using the Ryan-Holm stepdown Bonferroni procedure. McNemar's test was used to examine the change from baseline to 12-month follow-up for walking versus all other forms of school transport at the intervention or control schools.
At baseline, the proportions of students (n = 653) walking to the intervention (20% +/- 2%) or control schools (15% +/- 2%) did not differ (p = 0.39). At 12-month follow up, higher proportions of students (n = 643, p = 0.001)) walked to the intervention (25% +/- 2%) versus the control schools (7% +/- 1%). No significant changes were noted in the proportion of students riding in a car or taking the school bus at baseline or 12-month follow up (all p > 0.05). Comparing baseline to 12-month follow up, the numbers of students who walked to the intervention school increased while the numbers of students who used the other forms of transport did not change (p < 0.0001). In contrast, the numbers of students who walked to the control schools decreased while the numbers of students who used the other forms of transport did not change (p < 0.0001).
A WSB program is a promising intervention among urban, low-income elementary school students that may promote favorable changes toward active transport to school.
ClinicalTrials.gov NCT00402701.
This report provides detailed information on how the 2000 Centers for Disease Control and Prevention (CDC) growth charts for the United States were developed, expanding upon the report that accompanied the initial release of the charts in 2000.
The growth charts were developed with data from five national health examination surveys and limited supplemental data. Smoothed percentile curves were developed in two stages. In the first stage, selected empirical percentiles were smoothed with a variety of parametric and nonparametric procedures. In the second stage, parameters were created to obtain the final curves, additional percentiles and z-scores. The revised charts were evaluated using statistical and graphical measures.
The 1977 National Center for Health Statistics (NCHS) growth charts were revised for infants (birth to 36 months) and older children (2 to 20 years). New body mass index-for-age (BMI-for-age) charts were created. Use of national data improved the transition from the infant charts to those for older children. The evaluation of the charts found no large or systematic differences between the smoothed percentiles and the empirical data.
The 2000 CDC growth charts were developed with improved data and statistical procedures. Health care providers now have an instrument for growth screening that better represents the racial-ethnic diversity and combination of breast- and formula-feeding in the United States. It is recommended that these charts replace the 1977 NCHS charts when assessing the size and growth patterns of infants, children, and adolescents.
Until recently, our understanding of the childhood antecedents of adult cardiovascular disease was limited mainly to autopsy studies and pathologic findings in teens and young adults who died from accidental causes. Recent advances in the understanding of atherosclerosis and new technologies allowing detection of early events have made it possible to observe anatomic and physiologic evidence of cardiovascular disease in young adults and children.
The goal of this article was to introduce pediatricians to new methods for noninvasive measurement of cardiovascular disease and its precursors, to describe the potential application of these techniques in detecting childhood precursors of adult cardiovascular disease, and to summarize knowledge gained from this approach.
We conducted a computerized search of peer-reviewed articles listed in PubMed and Medline from 1980 to April 2006. We reviewed 63 and 84 articles from the adult and pediatric literature, respectively.
Reviewing the research on childhood antecedents of adult cardiovascular disease is sobering. Vascular alterations in anatomy, physiology, mechanical properties, and proinflammatory and prothrombotic changes are present from a very early age of childhood and are associated with the risk factors common in adult cardiovascular disease. At the same time, this body of research supports the concept that the vascular impairment from childhood may improve over time with appropriate intervention.
The measurement tools and concepts described in this article offer diagnostic and therapeutic opportunities for collaboration between clinical pediatricians and pediatric researchers. These partnerships will enable pediatricians to contribute in an effort to reduce the burdens of cardiovascular disease to individuals, families, and society.
Background
The recent decline in children’s active commuting (walking or biking) to school has become an important public health issue. Recent programs have promoted the positive effects of active commuting on physical activity (PA) and overweight. However, the evidence supporting such interventions among schoolchildren has not been previously evaluated.
Methods
This article presents the results of a systematic review of the association between active commuting to school and outcomes of PA, weight, and obesity in children.
Results
We found 32 studies that assessed the association between active commuting to school and PA or weight in children. Most studies assessing PA outcomes found a positive association between active commuting and overall PA levels. However, almost all studies were cross-sectional in design and did not indicate whether active commuting leads to increased PA or whether active children are simply more likely to walk. Only 3 of 18 studies examining weight found consistent results, suggesting that there might be no association between active commuting and reduced weight or body mass index.
Conclusion
Although there are consistent findings from cross-sectional studies associating active commuting with increased total PA, interventional studies are needed to help determine causation.
Rising rates of overweight children have focused attention on walking and biking to school as a means to increase children's physical activity levels. Despite this attention, there has been little documentation of trends in school travel over the past 30 years or analysis of what has caused the changes in mode choice for school trips.
This article analyzes data from the 1969, 1977, 1983, 1990, 1995, and 2001 National Personal Transportation Survey conducted by the U.S. Department of Transportation to document the proportion of students actively commuting to school in aggregate and by subgroups and analyze the relative influence of trip, child, and household characteristics across survey years. All analyses were done in 2006.
The National Personal Transportation Survey data show that in 1969, 40.7% (95% confidence interval [CI]=37.9-43.5) of students walked or biked to school; by 2001, the proportion was 12.9% (95% CI=11.8-13.9). Distance to school has increased over time and may account for half of the decline in active transportation to school. It also has the strongest influence on the decision to walk or bike across survey years.
Declining rates of active transportation among school travelers represents a worrisome loss of physical activity. Policymakers should continue to support programs designed to encourage children to walk to school such as Safe Routes to School and the Centers for Disease Control and Prevention's KidsWalk. In addition, officials need to design policies that encourage schools to be placed within neighborhoods to ensure that the distance to school is not beyond an acceptable walking distance.
Background:
Few reports examined long term predictors of children's active commuting to school (walking or cycling to school, ACS).
Purpose:
To identify predictors of ACS over 1 school year among a sample of children with relatively high rates of ACS.
Methods:
Parents were surveyed in September 2010 (Time 1) and April 2011 (Time 2). The dependent variable was children's commuting mode to school (active versus passive). Independent variables included: 1) parents' outcome expectations (from Social Cognitive Theory: the expected risks/benefits for their child doing ACS), 2) distance to school, 3) participation in an adult-led walk to school group, 4) temperature, and 5) child demographics. Generalized mixed-models estimated odds ratios for ACS (n = 369 or 49.7% of Time 1 respondents).
Results:
Males (OR = 2.59, 95% CI [1.57-4.30]), adult-led walk to school group participation (OR = 1.80, 95% CI [1.14-2.86]), parents' outcome expectations (OR = 1.26, 95% CI [1.14-1.39]), temperature (OR = 1.03, 95% CI [1.01-1.07), distance to school (OR = 0.23, 95% CI [0.14-0.37]), and Latino ethnicity (OR = 0.28, 95% CI [0.12-0.65]) were associated with ACS.
Conclusions:
Programs and policies sensitive to parents' concerns (eg, adult-led walk to school groups) and targeting Latinos and girls appear promising for increasing ACS.
Although eliminating health disparities by race, ethnicity, and socioeconomic status (SES) is a top public health priority internationally and in the United States, weight-related racial/ethnic and SES disparities persist among adults and children in the United States. Few studies have examined how these disparities have changed over time; these studies are limited by the reliance on rate differences or ratios to measure disparities. We sought to advance existing research by using a set of disparity metrics on both the absolute and relative scales to examine trends in childhood obesity disparities over time.
Data from 7066 children, ages 2 to 18 years, in the National Health and Nutrition Examination Surveys were used to explore trends in racial/ethnic and SES disparities in pediatric obesity from 2001 to 2010 using a set of different disparity metrics.
Racial/ethnic and SES-related disparities in pediatric obesity did not change significantly from 2001 to 2010 and remain significant.
Disparities in obesity have not improved during the past decade. The use of different disparity metrics may lead to different conclusions with respect to how disparities have changed over time, highlighting the need to evaluate disparities using a variety of metrics.
Objectives. Obesity has become a global epidemic but our understanding of the problem in children is limited due to lack of comparable representative data from different countries, and varying criteria for defining obesity. This paper summarises the available information on recent trends in child overweight and obesity prevalence. Methods. PubMed was searched for data relating to trends over time, in papers published between January 1980 and October 2005. Additional studies identified by citations in retrieved papers and by consultation with experts were included. Data for trends over time were found for school-age populations in 25 countries and for pre-school populations in 42 countries. Using these reports, and data collected for the World Health Organization's Burden of Disease Program, we estimated the global prevalence of overweight and obesity among school-age children for 2006 and likely prevalence levels for 2010. Results. The prevalence of childhood overweight has increased in almost all countries for which data are available. Exceptions are found among school-age children in Russia and to some extent Poland during the 1990s. Exceptions are also found among infant and pre-school children in some lower-income countries. Obesity and overweight has increased more dramatically in economically developed countries and in urbanized populations. Conclusions. There is a growing global childhood obesity epidemic, with a large variation in secular trends across countries. Effective programs and policies are needed at global, regional and national levels to limit the problem among children.
To analyze changes in BMI, according to gender and race/ethnicity, in a nationally representative cohort of children in the United States during their elementary and middle school years to identify critical periods of excess BMI gains.
The Early Childhood Longitudinal Study-Kindergarten Class monitored a nationally representative cohort of kindergarten students over 9 years (1998-2007). Height and weight measurements were available for 4240 white, 640 black, and 1070 Hispanic children in kindergarten and 1st, 3rd, 5th, and 8th grades. In each wave, we estimated the proportions of children with BMI values in each quartile of the Centers for Disease Control and Prevention reference-population distribution according to gender and race/ethnicity. We conducted nonparametric tests of differences in BMI distributions over time within racial/ethnic groups and across racial/ethnic groups in each wave. Piecewise linear growth models were estimated to test for specific time periods during which the largest gains in BMI percentiles occurred.
Overall, nearly 40% of children started kindergarten with a BMI in the top quartile of the growth charts (BMI > 75th percentile). This proportion increased significantly during the elementary school years, and the largest gains were between 1st and 3rd grades (5.8 percentage points), but there was no further increase during middle school. Increases in BMI percentiles over time were most notable among Hispanic children and black girls.
The early school years might be a critical time for excess BMI gains, even among children with normal BMI values at kindergarten entry.
The White House Task Force on Childhood Obesity has set a goal of increasing walking and biking to school by 50% within 5 years. Meeting the goal requires a detailed understanding of the current patterns of school travel.
To document nationally representative estimates of the amount of school travel and the modes used to access school in 2009 and compare these levels with 1969, 1995, and 2001.
The National Household Travel Survey collected data on the travel patterns of 150,147 households in 2008 and 2009. Analyses, conducted in 2010, documented the time, vehicle miles traveled, and modes used by American students to reach school. A binary logit model assessed the influence of trip, child, and household characteristics on the decision to walk to school.
In 2009, 12.7% of K-8 students usually walked or biked to school compared with 47.7% in 1969. Rates of walking and biking to school were higher on the trip home from school in each survey year. During the morning peak period, school travel accounted for 5%-7% of vehicle miles traveled in 2009 and 10%-14% of all private vehicles on the road.
There have been sharp increases in driving children to school since 1969 and corresponding decreases in walking to school. This increase is particularly evident in the number of vehicle trips generated by parents dropping children at school and teens driving themselves. The NHTS survey provides a unique opportunity to monitor these trends in the future.
The impact of neighborhood walkability (based on street connectivity and traffic exposure) within 2 km of public primary schools on children regularly walking to school was examined. The most (n=13) and least walkable (n=12) schools were selected using a school-specific 'walkability' index and a cross sectional study undertaken of Year 5, 6 and 7 children (n=1480) and consenting parents (n=1332). After adjustment, regularly walking to school was higher in children attending schools in high walkable neighborhoods (i.e, high street connectivity and low traffic volume) (Odds ratio (OR) 3.63; 95% Confidence Interval (CI) 2.01-6.56), and less likely in neighborhoods with high connectivity but high traffic volume (OR 0.32; 95% CI 0.22-0.47). Connected street networks provide direct routes to school but when designed for heavy traffic, the potential for children to walk to school is reduced. This highlights the importance of carefully considering school siting and, particularly, street design in school neighborhoods.
Context is important for understanding and making change to improve health outcomes. The purpose of this study was to examine the relationship between parent perceptions of neighborhood and youth aerobic physical activity and weight. This study is a secondary data analysis of 64,076 parents and guardians of children and adolescents (6-17 years) participating in the 2007 National Survey of Children's Health. Logistic regression models were used to evaluate the relationship between neighborhood characteristics, including constructs for social capital, physical condition, resource availability, and safety, and youth likelihood of meeting healthy standards for physical activity and weight. Neighborhood characteristics, including social capital, resource availability, and safety were significantly associated with increased likelihood of youth achieving healthy physical activity and normal weight parameters even with adjustment for individual and family-level demographic and behavioral characteristics. Findings support neighborhood assessment during behavioral counseling and continued exploration of neighborhood context as a means to positively impact youth physical activity and weight outcomes.
The emergence of Type 2 diabetes (T2D) in children and adolescents parallels the rising rates of childhood obesity. As a condition of impaired insulin sensitivity and relative insulin deficiency resulting in hyperglycemia, T2D has a complex underlying physiology that is reflected by the multiple approaches used to optimize medical care and prevent the myriad of diabetes-related complications. T2D diagnosed in children and adolescents represents a distinct and challenging condition to evaluate and treat. Here, we highlight the epidemiology, pathophysiology, risk factors, clinical presentation and diagnosis, treatment and public health impact of T2D in children and adolescents.
Walking to and from school has potential to increase daily physical activity among children.
A Walking School Bus (WSB) intervention was implemented for 2 years in 2 schools with a third school as a control. The primary aim evaluated school-wide prevalence of walking to school by self-report 6 times (fall, winter, spring). The secondary aims compared objective physical activity levels among a subsample of research participants (intervention [INT] = 201, control [CON] = 123) and between frequency of walking to school groups. INT and CON participants wore an accelerometer during 4 time periods to assess daily physical activity and were measured for body mass index (BMI) and body fat each fall and spring.
School-wide prevalence of walking to school frequently (> 50% of the time each week) was 27% higher in the WSB schools than in the control school. INT obtained significantly more daily physical activity than CON (78.0 [38.9] vs 60.6 [27.7] min/d, P < .05). In addition, across all schools, frequent walkers obtained 25% more physical activity (P < .05), gained 58% less body fat (P < .05), and attenuated BMI by 50% (P < .05) compared with passive commuters.
This study suggests a WSB intervention may increase frequency of walking to school and establishes a link with increased daily physical activity.
Over the past decade, childhood obesity has been recognized as an increasing health problem worldwide. It is a predictor of obesity during adulthood, which is strongly linked to chronic lifestyle diseases.
This paper aims to evaluate the effectiveness of school-based programs in the prevention and management of childhood obesity.
A comprehensive literature search was undertaken for RCTs and clinical controlled trials on school-based interventions that addressed childhood obesity, published between 1995 and 2007. The papers included for the meta-analysis were those in which ORs or standardized mean differences and their 95% CIs were reported or could be calculated from available data.
Meta-analysis showed that the odds of participants' being overweight and obese in the school-based intervention programs compared with the control arm were significantly protective in the short term (OR=0.74, 95% CI=0.60, 0.92). Interventions that were conducted for more than 1 year had a higher OR of decreasing the prevalence of obesity. However, intervention programs were not effective in decreasing BMI compared with control treatments, with a weighted mean difference of -0.62 (95% CI=-1.39, 0.14).
This meta-analysis showed that there was convincing evidence that school-based interventions are effective, at least short-term, in reducing the prevalence of childhood obesity. Longer-running programs were more effective than shorter programs.
The United States is currently experiencing an epidemic of children who are overweight or obese. Recently, research on child
obesity has begun to examine the relationship between neighborhood environments and the health behaviors of youths. The current
study used growth curve analysis based on multilevel modeling to examine the relationship between parents' perceptions of
neighborhood safety and children's body mass index (BMI). Parents' perceptions of neighborhood safety had a significant association
with children's BMI, and this relationship was fully mediated by television viewing. The results of this study suggest that
when parents perceive their neighborhood to be unsafe, they will restrict their children's outdoor activities and increase
the likelihood of sedentary indoor activity. Policies aimed at reducing overweight and obesity in children should take into
account the neighborhood contexts in which children live.
The recent decline in children's active commuting (walking or biking) to school has become an important public health issue. Recent programs have promoted the positive effects of active commuting on physical activity (PA) and overweight. However, the evidence supporting such interventions among schoolchildren has not been previously evaluated.
This article presents the results of a systematic review of the association between active commuting to school and outcomes of PA, weight, and obesity in children.
We found 32 studies that assessed the association between active commuting to school and PA or weight in children. Most studies assessing PA outcomes found a positive association between active commuting and overall PA levels. However, almost all studies were cross-sectional in design and did not indicate whether active commuting leads to increased PA or whether active children are simply more likely to walk. Only 3 of 18 studies examining weight found consistent results, suggesting that there might be no association between active commuting and reduced weight or body mass index.
Although there are consistent findings from cross-sectional studies associating active commuting with increased total PA, interventional studies are needed to help determine causation.
The association between physical activity and overall and site-specific cancer risk is elaborated in relation to whether any observed dose-response association between physical activity and cancer can be interpreted in terms of how much physical activity (type, intensity, duration, frequency) is needed to influence site- and gender-specific cancer risk.
Observational studies were reviewed that have examined the independent effect of the volume of occupational physical activity (OPA) and/or leisure time physical activity (LPA) on overall and site-specific cancer risk.
The evidence of cohort and case-control studies suggests that both leisure time and occupational physical activity protect against overall cancer risk, with a graded dose-response association suggested in both sexes. Confounding effects such as diet, body weight, and parity are often included as a covariate in the analyses, with little influence on the observed associations. A crude graded inverse dose-response association was observed between physical activity and colon cancer in 48 studies including 40,674 colon/colorectal cancer cases for both sexes. A dose-response effect of physical activity on colon cancer risk was especially observed, when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed as MET-hours per week. An observed inverse association with a dose-response relationship between physical activity and breast cancer was also identified in the majority of the 41 studies including 108,031 breast cancer cases. The dose-response relationship was in particular observed in case-control studies and supported by observations in cohort studies when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed by MET-hours per week. This association between physical activity and breast cancer risk is possibly dependent on age at exposure, age at diagnosis, menopausal status and other effect modifiers, e.g., body mass index. Furthermore, data concerning carcinoma of other cancers (prostate, lung, endometrium, ovary, and testicular cancers) are required.
A protective effect of physical activity on site-specific cancer risk with a dose-response association between physical activity and colon and pre- and postmenopausal breast cancer supported by identified biological mechanisms has been observed. The optimal permutation of type, intensity, duration, and frequency of physical activity across the lifespan is unclear, but it is gender, age, and site specific and supports moderate activity (>4.5 MET) more than light activities (<4.5 MET). The complicated nature of the physical activity variable, combined with lack of knowledge regarding possible biological mechanisms operating between physical activity and cancer, warrants further studies including controlled clinical randomized trials.
Convincing epidemiologic evidence currently exists for an association between physical activity and the prevention of colon and breast cancer Physical activity may also reduce the risk of cancer at several other sites. With increasing research on this topic, it is apparent that studies of physical activity and cancer have numerous methodological similarities with studies of nutrition and cancer Lessons learned from nutritional epidemiology that can be applied to studies of physical activity and cancer prevention and recommendations for future research are discussed in this review.
Scientific evidence is accumulating on physical activity as a means for the primary prevention of cancer. Nearly 170 observational epidemiologic studies of physical activity and cancer risk at a number of specific cancer sites have been conducted. The evidence for decreased risk with increased physical activity is classified as convincing for breast and colon cancers, probable for prostate cancer, possible for lung and endometrial cancers and insufficient for cancers at all other sites. Despite the large number of studies conducted on physical activity and cancer, most have been hampered by incomplete assessment of physical activity and a lack of full examination of effect modification and confounding. Several plausible hypothesized biological mechanisms exist for the association between physical activity and cancer, including changes in endogenous sexual and metabolic hormone levels and growth factors, decreased obesity and central adiposity and possibly changes in immune function. Weight control may play a particularly important role because links between excess weight and increased cancer risk have been established for several sites, and central adiposity has been particularly implicated in promoting metabolic conditions amenable to carcinogenesis. Based on existing evidence, some public health organizations have issued physical activity guidelines for cancer prevention, generally recommending at least 30 min of moderate-to-vigorous intensity physical activity on > or =5 d/wk. Although most research has focused on the efficacy of physical activity in cancer prevention, evidence is increasing that exercise also influences other aspects of the cancer experience, including cancer detection, coping, rehabilitation and survival after diagnosis.
Walking and biking to school can be an important part of a healthy lifestyle, yet most US children do not start their day with these activities.
The Safe Routes to School Program in Marin County, California, is working to promote walking and biking to school. Using a multipronged approach, the program identifies and creates safe routes to schools and invites communitywide involvement. By its second year, the program was serving 4665 students in 15 schools.
Participating public schools reported an increase in school trips made by walking (64%), biking (114%), and carpooling (91%) and a decrease in trips by private vehicles carrying only one student (39%).
United States National Health Objectives include increasing the proportion of trips made by walking to and from school for children who live within 1.6 km to 50%. The purpose of this objective is to increase the level of physical activity among children. However, the impact of walking, bicycling or skating (active commuting) to and from school on the prevalence of overweight is unknown.
Body mass index (BMI) was measured for 320 children (age 10.2+/-0.7 years) in September. Over 5 months, an active commuting index (SI) and daily physical activity were estimated via questionnaire. In April, BMI and body fat were measured.
A significant positive association was found between April BMI and SI adjusting for September BMI (partial r=0.03, P<0.05). Positive associations were found between SI and physical activity before school (r=0.17, P<0.05) and daily moderate intensity physical activity (r=0.13, P<0.05). There were no significant association between SI and BF (P>0.05).
This preliminary data suggests that active commuting does not appear to provide sufficient amounts of physical activity to attenuate BMI; however, it may contribute to the attainment of physical activity recommendations. Future research is needed to objectively measure the impact of active commuting on the prevalence of overweight.
Obesity is becoming a global epidemic in both children and adults. It is associated with numerous comorbidities such as cardiovascular diseases (CVD), type 2 diabetes, hypertension, certain cancers, and sleep apnea/sleep-disordered breathing. In fact, obesity is an independent risk factor for CVD, and CVD risks have also been documented in obese children. Obesity is associated with an increased risk of morbidity and mortality as well as reduced life expectancy. Health service use and medical costs associated with obesity and related diseases have risen dramatically and are expected to continue to rise. Besides an altered metabolic profile, a variety of adaptations/alterations in cardiac structure and function occur in the individual as adipose tissue accumulates in excess amounts, even in the absence of comorbidities. Hence, obesity may affect the heart through its influence on known risk factors such as dyslipidemia, hypertension, glucose intolerance, inflammatory markers, obstructive sleep apnea/hypoventilation, and the prothrombotic state, in addition to as-yet-unrecognized mechanisms. On the whole, overweight and obesity predispose to or are associated with numerous cardiac complications such as coronary heart disease, heart failure, and sudden death because of their impact on the cardiovascular system. The pathophysiology of these entities that are linked to obesity will be discussed. However, the cardiovascular clinical evaluation of obese patients may be limited because of the morphology of the individual. In this statement, we review the available evidence of the impact of obesity on CVD with emphasis on the evaluation of cardiac structure and function in obese patients and the effect of weight loss on the cardiovascular system.
To determine if there is a relationship between parental perception of neighborhood safety and overweight at the age of 7 years.
Cross-sectional analysis of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development.
Ten urban and rural US sites.
A total of 768 children selected via conditional random sampling with complete data at follow-up.
Parents reported demographics and perception of neighborhood safety by standardized questionnaire. Child overweight status was defined as a body mass index greater than or equal to the 95th percentile for age and sex from measured anthropometrics at the age of 7 years. The base model included relationship of the safety reporter to the child, sex, and baseline body mass index z score at the age of 4.5 years. Covariates tested included maternal marital status, education, and depressive symptoms; child race/ethnicity; participation in structured after-school activities; Home Observation for Measurement of the Environment total score; and neighborhood social cohesiveness.
The sample was 85% white, and 10% of the children were overweight. Neighborhood safety ratings in the lowest quartile were independently associated with a higher risk of overweight at the age of 7 years compared with safety ratings in the highest quartile (adjusted odds ratio, 4.43; 95% confidence interval, 2.03-9.65). None of the candidate covariates altered the relationship between perception of neighborhood safety and child overweight status.
Perception of the neighborhood as less safe was independently associated with an increased risk of overweight at the age of 7 years. Public health efforts may benefit from policies directed toward improving both actual and perceived neighborhood safety.
Active commuting to school may be an important opportunity for children to accumulate adequate physical activity for improved cardiovascular risk factors, enhanced bone health, and psychosocial well-being. The purpose of this study was to examine personal, family, social, and environmental correlates of active commuting to school among children.
Cross-sectional study of 235 children aged 5 to 6 years and 677 children aged 10 to 12 years from 19 elementary schools in Melbourne, Australia. Self-administered questionnaires were completed by parents, and the older children. The shortest possible routes to school were examined using a geographic information system.
Among both age groups, negative correlates of active commuting to school included parental perception of few other children in the neighborhood and no lights or crossings for their child to use, and an objectively assessed busy road barrier en route to school. In younger children, an objectively assessed steep incline en route to school was negatively associated with walking or cycling to school. Good connectivity en route to school was negatively associated with walking or cycling to school among older children. Among both age groups, children were more likely to actively commute to school if their route was <800 meters. There were no associations with perceived energy levels or enjoyment of physical activity, weight status, or family factors.
For children, creating child-friendly communities and providing skills to safely negotiate the environment may be important. Environmental correlates of active transport in children and adults may differ and warrant further investigation.
Obesity is becoming a global epidemic in both children and adults, and it is associated with numerous co-morbidities such as cardiovascular diseases (CVD), type 2 diabetes, hypertension, certain cancers, and sleep apnea/sleep-disordered breathing. In fact, is an independent risk factor for CVD and CVD risks have been also documented in obese children, and is associated with reduced life expectancy. A variety of adaptations/alterations in cardiac structure and function occur in the individual as adipose tissue accumulates in excess amount. As a whole, overweight/obesity predispose or is associated with numerous cardiac complications such as coronary heart disease, heart failure, and sudden death through its impact on the cardiovascular system.
This study examined the association of objective and perceived neighborhood environmental characteristics and parent concerns with active commuting to school, investigated whether parental concerns varied by environmental characteristics, and compared the association of the perceived environment, parental concerns, and objective environment on the outcome active commuting to school.
Randomly selected parents of children (aged 5-18 yr), in neighborhoods chosen for their variability in objectively measured walkability and income, completed questionnaires about their neighborhood environment, concerns about children walking to school, and children's behavior (N = 259). Objective measures of the environment were available for each participant and each neighborhood. Logistic regression analyses were used to investigate the relationships among environment, parental concerns, and walking or biking to or from school at least once a week.
A parental concerns scale was most strongly associated with child active commuting (odds ratio: 5.2, 95% CI: 2.71-9.96). In high-income neighborhoods, more children actively commuted in high-walkable (34%) than in low-walkable neighborhoods (23%) (odds ratio: 2.1, 95% CI: 1.12-3.97), but no differences were noted in low-income neighborhoods. Parent concerns and neighborhood aesthetics were independently associated with active commuting. Perceived access to local stores and biking or walking facilities accounted for some of the effect of walkability on active commuting.
Both parent concerns and the built environment were associated with children's active commuting to school. To increase active commuting to school, interventions that include both environmental change and education campaigns may be needed.
Background:
Clinical trials have shown that exercise in adults with overweight or obesity can reduce bodyweight. There has been no quantitative systematic review of this in The Cochrane Library.
Objectives:
To assess exercise as a means of achieving weight loss in people with overweight or obesity, using randomised controlled clinical trials.
Search strategy:
Studies were obtained from computerised searches of multiple electronic bibliographic databases. The last search was conducted in January 2006.
Selection criteria:
Studies were included if they were randomised controlled trials that examined body weight change using one or more physical activity intervention in adults with overweight or obesity at baseline and loss to follow-up of participants of less than 15%.
Data collection and analysis:
Two authors independently assessed trial quality and extracted data.
Main results:
The 43 studies included 3476 participants. Although significant heterogeneity in some of the main effects' analyses limited ability to pool effect sizes across some studies, a number of pooled effect sizes were calculated. When compared with no treatment, exercise resulted in small weight losses across studies. Exercise combined with diet resulted in a greater weight reduction than diet alone (WMD -1.1 kg; 95% confidence interval (CI) -1.5 to -0.6). Increasing exercise intensity increased the magnitude of weight loss (WMD -1.5 kg; 95% CI -2.3 to -0.7). There were significant differences in other outcome measures such as serum lipids, blood pressure and fasting plasma glucose. Exercise as a sole weight loss intervention resulted in significant reductions in diastolic blood pressure (WMD -2 mmHg; 95% CI -4 to -1), triglycerides (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1) and fasting glucose (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1). Higher intensity exercise resulted in greater reduction in fasting serum glucose than lower intensity exercise (WMD -0.3 mmol/L; 95% CI -0.5 to -0.2). No data were identified on adverse events, quality of life, morbidity, costs or on mortality.
Authors' conclusions:
The results of this review support the use of exercise as a weight loss intervention, particularly when combined with dietary change. Exercise is associated with improved cardiovascular disease risk factors even if no weight is lost.
To prospectively examine potential benefits of active commuting to school on measures of weight status and physical activity in a sample of youth.
A cohort of students from seven elementary schools was measured four times--in the fall and spring of fourth grade (N = 1083) and fifth grade (N = 924). Participants were classified as active (walking, biking, or skateboarding to school almost every day for baseline analyses or at least 2 d/wk for analyses of consistent active commuting) or non-active commuters to school. Accelerometers were used to measure physical activity. Height, weight, and skinfolds were objectively assessed.
Boys who actively commuted to school had lower BMI (p < 0.01) and skinfolds (p < 0.05) than non-active commuters to school in the fourth grade. Active commuting to school over 2 years was not associated with BMI change or overweight status.
Walking and cycling to school may contribute to preventing excessive weight gain, or leaner children may walk or cycle to school.
To examine how "travel by walking" before and after school contributes to total physical activity of adolescent girls.
Cross-sectional sample.
Thirty-six middle schools from Arizona, Maryland, Minnesota, Louisiana, California, and South Carolina participating in the Trial of Activity for Adolescent Girls (TAAG).
Seventeen hundred twenty-one sixth-grade girls consented to participate; adequate information was available for 1596 participants (93%).
Travel by walking before school, after school, and before and after school combined assessed from the 3-Day Physical Activity Recall.
Mean minutes of physical activity measured by accelerometry were estimated for total physical activity (light, moderate, vigorous), moderate to vigorous activity (MVPA), and MVPA of 3 metabolic equivalents.
Travel by walking was reported by 14% of participants before school and 18% after school. Girls who reported travel by walking before and after school (combined) had 13.7 more minutes (95% confidence interval, 1.2-26.3) of total physical activity and 4.7 more minutes (95% confidence interval, 2.2-7.2) of MVPA than girls who did not report this activity. Before-school and after-school walkers (but not both) accumulated 2.5 more minutes (95% confidence interval, 0.10-4.9) and 2.2 more minutes (95% confidence interval, 0.24-4.2) of MVPA on an average weekday, respectively, than nonwalkers.
Our results provide evidence that walking to and from school increases weekday minutes of total physical activity and MVPA for middle-school girls.
Keywords:Exercise;obesity;physical activity;prevention
Type 2 diabetes mellitus (T2DM) has dramatically increased throughout the world in many ethnic groups and among people with diverse social and economic backgrounds. This increase has also affected the young such that over the past decade, the increase in the number of children and youth with T2DM has been labeled an 'epidemic'. Before the 1990s, it was rare for most pediatric centers to have significant numbers of patients with T2DM. However, by 1994, T2DM patients represented up to 16% of new cases of diabetes in children in urban areas and by 1999, depending on geographic location, the range of percentage of new cases because of T2DM was 8-45% and disproportionately represented among minority populations. Although the diagnosis was initially regarded with skepticism, T2DM is now a serious diagnostic consideration in all young people who present with signs and symptoms of diabetes in the USA.
Over the last decade, it has become apparent that type 2 diabetes extends not only into the young adult population but is also found in adolescents and even, occasionally, in children. The limited data that are currently available present a rather uncertain picture, with a rather wide range of prevalences and incidences of type 2 diabetes in children and adolescents. Not surprisingly, the majority of the cases, and the highest prevalences, have been found among ethnic groups known to be at high risk of adult type 2 diabetes. Nevertheless, even in European populations, where the prevalence of type 2 diabetes remains very low among children and adolescents and certainly is considerably smaller than type 1 diabetes, there are several cases reported. The risk factors for type 2 diabetes in children and adolescents are, as expected, similar to those seen in adults, with obesity being almost always present. In utero exposure to hyperglycemia now appears to be an additional risk factor to having a family history of diabetes and suggests that better management of diabetes in pregnancy and prevention of gestational diabetes may reduce the risk of diabetes developing in the offspring.
To describe physical activity levels of children (6-11 yr), adolescents (12-19 yr), and adults (20+ yr), using objective data obtained with accelerometers from a representative sample of the U.S. population.
These results were obtained from the 2003-2004 National Health and Nutritional Examination Survey (NHANES), a cross-sectional study of a complex, multistage probability sample of the civilian, noninstitutionalized U.S. population in the United States. Data are described from 6329 participants who provided at least 1 d of accelerometer data and from 4867 participants who provided four or more days of accelerometer data.
Males are more physically active than females. Physical activity declines dramatically across age groups between childhood and adolescence and continues to decline with age. For example, 42% of children ages 6-11 yr obtain the recommended 60 min x d(-1) of physical activity, whereas only 8% of adolescents achieve this goal. Among adults, adherence to the recommendation to obtain 30 min x d(-1) of physical activity is less than 5%.
Objective and subjective measures of physical activity give qualitatively similar results regarding gender and age patterns of activity. However, adherence to physical activity recommendations according to accelerometer-measured activity is substantially lower than according to self-report. Great care must be taken when interpreting self-reported physical activity in clinical practice, public health program design and evaluation, and epidemiological research.