***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Childhood obesity is a major public health problem in the United States , particularly among American Indian communities . OBJECTIVE The objective was to evaluate the effectiveness of a school-based , multicomponent intervention for reducing percentage body fat in American Indian schoolchildren . DESIGN This study was a r and omized , controlled , school-based trial involving 1704 children in 41 schools and was conducted over 3 consecutive years , from 3rd to 5th grade s , in schools serving American Indian communities in Arizona , New Mexico , and South Dakota . The intervention had 4 components : 1 ) change in dietary intake , 2 ) increase in physical activity , 3 ) a classroom curriculum focused on healthy eating and lifestyle , and 4 ) a family-involvement program . The main outcome was percentage body fat ; other outcomes included dietary intake , physical activity , and knowledge , attitudes , and behaviors . RESULTS The intervention result ed in no significant reduction in percentage body fat . However , a significant reduction in the percentage of energy from fat was observed in the intervention schools . Total energy intake ( by 24-h dietary recall ) was significantly reduced in the intervention schools but energy intake ( by direct observation ) was not . Motion sensor data showed similar activity levels in both the intervention and control schools . Several components of knowledge , attitudes , and behaviors were also positively and significantly changed by the intervention . CONCLUSIONS These results document the feasibility of implementing a multicomponent program for obesity prevention in elementary schools serving American Indian communities . The program produced significant positive changes in fat intake and in food- and health-related knowledge and behaviors . More intense or longer interventions may be needed to significantly reduce adiposity in this population A health education intervention was carried out for three consecutive years on primary school Cretan children . Baseline measures were obtained from 962 pupils ( 509 boys and 453 girls ) registered in first grade in 1992 . The health education intervention programme was directed at both the children of the intervention group and their parents , and has a projected duration of 6 years . After the completion of the 3 years of intervention and while pupils were in fourth grade , measures were obtained for evaluation purpose s on a r and om sub sample of 393 pupils of the original cohort . Statistically greater improvements in the intervention , as opposed to the control group , were observed for both children 's and parents ' health knowledge , and children 's st and ing broad jump , sit-ups ( SUP ) , sit- and -reach , h and grip and endurance run test ( ERT ) . Furthermore , time spent on moderate to vigorous physical activities out of school significantly increased for intervention group children compared to the control group . Statistically smaller increases in the intervention as opposed to the control group were observed in suprailiac skinfold and body mass index . The degree of improvement in both SUP and ERT related positively to parent 's baseline physical activity score . Finally , the parental attitude of health-related hedonism related negatively to SUP improvement OBJECTIVE To examine how fitness in both childhood and adulthood is associated with  adult obesity  and insulin resistance . RESEARCH DESIGN AND METHODS A prospect i ve cohort study set in Australia in 2004–2006 followed up a cohort of 647 adults who had participated in the Australian Schools Health and Fitness Survey in 1985 and who had undergone anthropometry and cardiorespiratory fitness assessment during the survey . Outcome measures were insulin resistance and obesity , defined as a homeostasis model assessment index above the 75th sex-specific percentile and BMI ≥30 kg/m2 , respectively . RESULTS Lower levels of child cardiorespiratory fitness were associated with increased odds of adult obesity ( adjusted odds ratio [ OR ] per unit decrease 3.0 [ 95 % CI 1.6–5.6 ] ) and insulin resistance ( 1.7 [ 1.1–2.6 ] ) . A decline in fitness level between childhood and adulthood was associated with increased obesity ( 4.5 [ 2.6–7.7 ] ) and insulin resistance ( 2.1 [ 1.5–2.9 ] ) per unit decline . CONCLUSIONS A decline in fitness from childhood to adulthood , and by inference a decline in physical activity , is associated with obesity and insulin resistance in adulthood . Programs aim ed at maintaining high childhood physical activity levels into adulthood may have potential for reducing the burden of obesity and type 2 diabetes in adults Objective . To evaluate the effectiveness of a 12-month multicomponent  obesity prevention intervention . Setting . 9 elementary schools in Santiago , Chile . Subjects . 6–8 y old low-income children ( N = 1474 ) . Design . R and omized controlled study ; 5 intervention/4 control schools . We trained teachers to deliver nutrition contents and improve the quality of PE classes . We determined % healthy snacks brought from home , children 's nutrition knowledge , nutritional status , duration of PE classes , and % time in moderate/vigorous activity ( MVA ) . Effectiveness was determined by comparing Δ BMI Z between intervention and control children using PROCMIXED . Results . % obesity increased in boys from both types of schools and in girls from control schools , while decreasing in girls from intervention schools ( all nonsignificant ) . % class time in MVA declined ( 24.5–16.2 ) while remaining unchanged ( 24.8–23.7 % ) in classes conducted by untrained and trained teachers , respectively . In boys , BMI Z declined ( 1.33–1.24 ) and increased ( 1.22–1.35 ) in intervention and control schools , respectively . In girls , BMI Z remained unchanged in intervention schools , while increasing significantly in control schools ( 0.91–1.06 , P = 0.024 ) . Interaction group ∗ time was significant for boys ( P < 0.0001 ) and girls ( P = 0.004 ) . Conclusions . This intervention was effective in controlling obesity , but not preventing it . Even though impact was small , results showed that when no intervention is implemented , obesity increases Background and purpose A behavioral intervention is a program aim ed at modifying behavior for the purpose of treating or preventing disease , promoting health , and /or enhancing well-being . Many behavioral interventions are dynamic treatment regimens , that is , sequential , individualized multicomponent interventions in which the intensity and /or type of treatment is varied in response to the needs and progress of the individual participant . The multiphase optimization strategy ( MOST ) is a comprehensive framework for development , optimization , and evaluation of behavioral interventions , including dynamic treatment regimens . The objective of optimization is to make dynamic treatment regimens more effective , efficient , scalable , and sustainable . An important tool for optimization of dynamic treatment regimens is the sequential , multiple assignment , r and omized trial ( SMART ) . The purpose of this article is to discuss how to develop optimized dynamic treatment regimens within the MOST framework . Methods and results The article discusses the preparation , optimization , and evaluation phases of MOST . It is shown how MOST can be used to develop a dynamic treatment regimen to meet a prespecified optimization criterion . The SMART is an efficient experimental design for gathering the information needed to optimize a dynamic treatment regimen within MOST . One signature feature of the SMART is that r and omization takes place at more than one point in time . Conclusion MOST and SMART can be used to develop optimized dynamic treatment regimens that will have a greater public health impact OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity OBJECTIVE To evaluate the effects of a comprehensive physical activity ( PA ) promotion programme in elementary schools on children 's total PA levels , leisure-time PA , physical fitness and psychosocial correlates of PA . DESIGN A pre-test-post-test design over two school years . SETTING AND SUBJECTS Sixteen elementary schools ( 764 children , mean age : 11.2 + /- 0.7 years ) were r and omly assigned to the intervention condition ( n = 8) and the control condition ( n = 8) . The intervention included a health-related physical education programme , an extracurricular PA promotion programme and classroom-based PA education lessons . In the total sample , leisure-time PA , psychosocial correlates of PA and physical fitness were measured using a PA question naire and the Eurofit test battery . In a sub- sample , total PA levels were measured using an accelerometer . RESULTS According to accelerometer data , children 's moderate PA and moderate-to-vigorous PA ( MVPA ) levels decreased less in the intervention schools than in the control schools ( P < 0.01 ) . The average time spent on MVPA decreased by 9 min per day in the intervention schools compared with 33 min per day in the control schools . Children in the intervention schools reported significantly more moderate PA in leisure time than the controls ( P < 0.05 ) . No overall improvement of physical fitness and no effects on the psychosocial correlates of PA were found . CONCLUSIONS The comprehensive PA promotion programme was successful in preventing a decline in children 's  total activity levels . Furthermore , the intervention increased children 's PA engagement in leisure time . Therefore , implementation needs to be encouraged BACKGROUND Physical inactivity is a risk behavior for cardiovascular and other diseases . Schools can promote public health objectives by increasing physical activity among youth . METHODS The Child and Adolescent Trial for Cardiovascular Health ( CATCH ) was a multicenter , r and omized trial to test the effectiveness of a cardiovascular health promotion program in 96 public schools in four states . A major component of CATCH was an innovative , health-related physical education ( P+ ) program . For 2.5 years , r and omly assigned schools received a st and ardized PE intervention , including curriculum , staff development , and follow-up . RESULTS Systematic analysis of 2,096 PE lessons indicated students engaged in more moderate-to-vigorous physical activity ( MVPA ) in intervention than in control schools ( P = 0.002 ) . MVPA during lessons in intervention schools increased from 37.4 % at baseline to 51.9 % , thereby meeting the established Year 2000 objective of 50 % . Intervention children reported 12 more min of daily vigorous physical activity ( P = 0.003 ) and ran 18.6 yards more than control children on a 9-min run test of fitness ( P = 0.21 ) . CONCLUSIONS The implementation of a st and ardized curriculum and staff development program increased children 's  MVPA in existing school PE classes in four geographic and ethnically diverse communities . CATCH PE provides a tested model for improving physical education in American schools OBJECTIVES We examined the relationship between comprehensive fitness tests and overweight using a school surveillance system in a racially diverse city in the United States . RESEARCH METHODS AND PROCEDURES Trained physical education teachers  measured weight , height , and fitness annually from 2001 to 2003 . We compiled data for a cross-sectional analysis ( 11,845 measurements on 6297 students , 5 to 14 years of age ) and a 1-year prospect i ve analysis ( 4215 measurements on 2927 students not overweight at baseline , 5 to 13 years of age ) . Overweight was defined as a BMI > or = 95th percentile ( Centers for Disease Control and Prevention 2000 growth charts ) , and underfit was defined as failing at least one of five fitness tests : endurance run , abdominal strength , flexibility , upper body strength , and agility ( Amateur Athletic Union and Fitnessgram ) . Associations between fitness and overweight were examined using multivariate logistic regression models , adjusting for sociodemographic status and repeated measurements over time . RESULTS The mean number of fitness tests passed was lower among students with a BMI above the 80th percentile . Overweight incidence over 
    Output:
    
PE interventions consistently showed increases in moderate-to-vigorous PA or vigorous PA during PE class but were less consistent in impacting leisure-time PA .
Half of the studies assessing fitness did not show a significant impact ; however , those that did were design ed to influence fitness outcomes .
Few studies assessed psychosocial determinants regarding PA , and no study demonstrated significant impacts on constructs other than knowledge .
Interventions often contained multiple components ( e.g. ,  diet , family )  implemented alongside PE interventions .