***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 Schools are the most frequent target for intervention programs aim ed at preventing child obesity ; however , the overall effectiveness of these programs has been limited . It has therefore been recommended that interventions target multiple ecological levels ( community , family , school and individual ) to have greater success in changing risk behaviors for obesity . This study examined the immediate and short-term , sustained effects of the Switch program , which targeted three behaviors ( decreasing children 's screen time , increasing fruit and vegetable consumption , and increasing physical activity ) at three ecological levels ( the family , school , and community ) . Methods Participants were 1,323 children and their parents from 10 schools in two states . Schools were matched and r and omly assigned to treatment and control . Measures of the key behaviors and body mass index were collected at baseline , immediately post-intervention , and 6 months post-intervention . Results The effect sizes of the differences between treatment and control groups ranged between small ( Cohen 's d = 0.15 for body mass index at 6 months post-intervention ) to large ( 1.38 ; parent report of screen time at 6 months post-intervention ) , controlling for baseline levels . There was a significant difference in parent-reported screen time at post-intervention in the experimental group , and this effect was maintained at 6 months post-intervention ( a difference of about 2 hours/week ) . The experimental group also showed a significant increase in parent-reported fruit and vegetable consumption while child-reported fruit and vegetable consumption was marginally significant . At the 6-month follow-up , parent-reported screen time was significantly lower , and parent and child-reported fruit and vegetable consumption was significantly increased . There were no significant effects on pedometer measures of physical activity or body mass index in the experimental group . The intervention effects were moderated by child sex ( for fruit and vegetable consumption , physical activity , and weight status ) , family involvement ( for fruit and vegetable consumption ) , and child body mass index ( for screen time ) . The perception of change among the experimental group was generally positive with 23 % to 62 % indicating positive changes in behaviors . Conclusion The results indicate that the Switch program yielded small-to-modest treatment effects for promoting children 's fruit and vegetable consumption and minimizing screen time . The Switch program offers promise for use in youth obesity prevention Objective To evaluate the effectiveness of a school-based intervention involving the families and teachers  that aim ed to promote healthy eating habits in adolescents ; the ultimate aim of the intervention was to reduce the increase in body mass index ( BMI ) of the students . Design Paired cluster r and omized school-based trial conducted with a sample of fifth grade rs . Setting Twenty classes were r and omly assigned into either an intervention group or a control group . Participants From a total of 574 eligible students , 559 students participated in the study (  intervention :  10 classes with 277 participants ;  control :  10 classes with 282 participants ) . The mean age of students was 11 years . Intervention Students attended 9 nutritional education sessions during the 2010 academic year . Parents/guardians and teachers received information on the same subjects . Main Outcome Measurement Changes in BMI and percentage of body fat . Results Intention-to-treat analysis showed that changes in BMI were not significantly different between the 2 groups ( β = 0.003 ; p = 0.75 ) . There was a major reduction in the consumption of sugar-sweetened beverages and cookies in the intervention group ; students in this group also consumed more fruits . Conclusion Encouraging the adoption of healthy eating habits promoted important changes in the adolescent diet , but this did not lead to a reduction in BMI gain . Strategies based exclusively on the quality of diet may not reduce weight gain among adolescents . Trial Registration Clinical trials.gov NCT01046474 The purpose of this study was to assess the effects of a six-months ’ nutrition program , delivered and taught by classroom teachers with in-service nutrition training , on the prevention of overweight and obesity among children in grade s 1 to 4 . In this r and omized trial , four hundred and sixty four children from seven elementary schools were allocated to a nutrition educational program delivered by their own teachers . Intervened teachers had 12 sessions of three hours each with the research ers throughout six months , according to the topics nutrition and healthy eating , the importance of drinking water and healthy cooking activities . After each session , teachers were encouraged to develop activities in class focused on the learned topics . Sociodemographic , anthropometric , dietary , and physical activity assessment s were performed at baseline and at the end of the intervention . In the intervention group the increase in Body Mass Index ( BMI ) z-score was significantly lower than in the control group ( p = 0.009 ) ; fewer proportion of children became overweight in the intervened group compared with the control ( 5.6 % vs. 18.4 % ; p = 0.037 ) . Our study provides further support to decrease the overweight epidemic , involving classroom teachers in a training program and making them dedicated interventionists Objectives To assess the behavioural and weight status outcomes in English children in a feasibility study of a novel primary school-based obesity prevention programme . Design Exploratory cluster r and omised controlled trial of the Healthy Lifestyles Programme . Setting Four city primary schools ( two control and two intervention ) in the South West of Engl and . Participants 202 children aged 9–10 years , of whom 193 and 188 were followed up at 18 and 24 months , respectively . No child was excluded from the study ; however , to be eligible , schools were required to have at least one single Year 5 class . Intervention Four-phase multicomponent programme using a range of school-based activities including lessons , assemblies , parents ' evenings , interactive drama workshops and goal setting to engage and support schools , children and their families in healthy lifestyle behaviours . It runs over the spring and summer term of Year 5 and the autumn term of Year 6 . Primary and secondary outcomes Weight status outcomes were body mass index , waist circumference and body fat st and ard deviation scores ( SDS ) at 18 and 24 months , and behavioural outcomes were physical activity , television ( TV ) viewing/screen time and food intake at 18 months . Results At 18 months of follow-up , intervention children consumed less energy-dense snacks and more healthy snacks ; had less ‘ negative food markers ’ , more ‘ positive food markers ’ , lower mean TV/screen time and spent more time doing moderate-vigorous physical activity each day than those in the control schools . Intervention children had lower anthropometric measures at 18 and 24 months than control children , with larger differences at 24 months than at 18 months for nearly all measures . Conclusions Results from this exploratory trial show consistent positive changes in favour of the intervention across all targeted behaviours , which , in turn , appear to affect weight status and body shape . A definitive trial is now justified OBJECTIVE To determine whether an educational programme aim ed at discouraging students from drinking sugar-sweetened beverages could prevent excessive weight gain . DESIGN Forty-seven classes in twenty-two schools were r and omised as intervention or control . SUBJECTS Participants were 1140 , 9 - 12-year-old fourth grade rs ( 435 in the intervention group and 608 in the control group ) .  Sugar-sweetened beverages and juice intake were measured through one 24 h recall at baseline and another at the end of the trial . The main outcome was the change in BMI ( BMI = weight (kg)/height ( m2 ) ) , measured at the beginning and at the end of the school year . Intention-to-treat analysis was performed taking into account the cluster ( classes ) effect . RESULTS A statistically significant decrease in the daily consumption of carbonated drinks in the intervention compared to control ( mean difference = -56 ml ; 95 % CI -119 , -7 ml ) was followed by a non-significant overall reduction in BMI , P = 0.33 . However , among those students overweight at baseline , the intervention group showed greater BMI reduction ( -0.4 kg/m2 compared with -0.2 kg/m2 in the control group ( P = 0.11 ) ) , and this difference was statistically significant among girls ( P = 0.009 ) . Fruit juice consumption was slightly increased in the intervention group ( P = 0.08 ) , but not among girls . CONCLUSION Decreasing sugar-sweetened beverages intake significantly reduced BMI  among overweight children , and mainly among girls . Efforts to reduce energy intake through liquids need to emphasise overall sweetened beverages and addition of sugar on juices Objectives To examine the prospect i ve associations between body mass index ( BMI ) , waist circumference , and fat mass in childhood and cardiovascular risk factors at age 15 - 16 . Design Prospect i ve cohort study . Setting Avon Longitudinal Study of Parents and Children . Participants 5235 children aged 9 - 12 at start of study . Main exposures BMI , waist circumference , and fat  mass determined by dual energy x ray absorptiometry , assessed at age 9 - 12 and at age 15 - 16 . Main outcome measures Systolic and diastolic blood pressure and concentrations of fasting glucose , insulin , triglycerides , low density lipoprotein cholesterol , and high density lipoprotein cholesterol assessed at age 15 - 16 . Results In girls a 1 SD greater BMI at age 9 - 12 was associated with cardiovascular risk factors at age 15 - 16 in fully adjusted models : odds ratio 1.23 ( 95 % confidence interval 1.10 to 1.38 ) for high systolic blood pressure ( ≥130 mm Hg ) ; 1.19 ( 1.03 to 1.38 ) for high concentration of low density lipoprotein cholesterol ( ≥2.79 mmol/l ) ; 1.43 ( 1.06 to 1.92 ) for high concentration of triglycerides ( ≥1.7 mmol/l ) ; 1.25 ( 1.08 to 1.46 ) for low concentration of high density lipoprotein cholesterol ( < 1.03 mmol/l ) ; and 1.45 ( 1.22 to 1.73 ) for high concentration of insulin ( ≥16.95 IU/l ) . Equivalent results in boys were 1.24 ( 1.13 to 1.37 ) for systolic blood pressure ; 1.30 ( 1.07 to 1.59 ) for low density lipoprotein cholesterol ; 1.96 ( 1.51 to 2.55 ) for triglycerides ; 1.39 ( 1.22 to 1.57 ) for high density lipoprotein cholesterol , and 1.84 ( 1.56 to 2.17 ) for insulin . BMI was associated with high fasting glucose ( ≥5.6 mmol/l ) only in boys ( 1.18 , 1.03 to 1.36 ) . With these binary outcomes there was statistical evidence that associations differed between girls and boys for fasting glucose ( P=0.03 ) and insulin ( P<0.001 ) . When risk factors were examined as continuous outcomes there was evidence for stronger associations of BMI with more adverse levels in boys than girls for fasting insulin , glucose , and triglyceride concentrations ( all interaction P≤0.03 ) . BMI , waist circumference , and fat mass were all strongly correlated with each other ( r=0.89 - 0.94 ) , and associations of the three with cardiovascular outcomes were of similar magnitude with statistical evidence of consistency in associations ( all P>0.2 for heterogeneity ) . When waist circumference or fat mass or both were added to models including BMI they did not increase the variation in cardiovascular risk factors already explained by BMI and confounders alone . Girls who were overweight/obese at age 9 - 12 but were normal weight by 15 - 16 had similar odds of adverse levels of risk factors to those who were normal weight at both ages . In boys odds of high systolic blood pressure , high concentrations of triglycerides and insulin , and low concentrations of high density lipoprotein cholesterol remained higher in this group compared with those who were normal weight at both ages but were lower than in those who remained overweight/obese at both ages . Conclusions Measurements of waist circumference or directly assessed fat mass in childhood do not seem to be associated with cardiovascular risk factors in adolescence any more strongly than BMI . Girls who favourably alter their overweight status between childhood and adolescence have cardiovascular risk profiles broadly similar to those who were normal weight at both time points , but boys who change from overweight to normal show risk factor profiles intermediate between those seen in boys who are normal weight at both ages or overweight at both ages OBJECTIVES : The objective of this study was to evaluate a 12-session home/community-based health promotion/obesity prevention program ( Challenge ! ) on changes in BMI status , body composition , physical activity , and diet . METHODS : A total of 235 black adolescents ( aged 11–16 years ; 38 % overweight/obese ) were recruited from low-income urban communities . Baseline measures included weight , height , body composition , physical activity ( PA ) , and diet . PA was measured by 7-day play-equivalent physical activity ( ≥1800 activity counts per minute ) . Participants were r and omly assigned to health promotion/obesity prevention that is anchored in social cognitive theory and motivational interviewing and was delivered by college-aged black mentors or to control . Postintervention ( 11 months ) and delayed follow-up ( 24 months ) evaluations were conducted . Longitudinal analyses used multilevel models with r and om intercepts and generalized estimating equations , controlling for baseline age/gender . Stratified analyses exam 
    Output:
    
RESULTS We found that interventions based only on advice had modest results in identifying changes in the anthropometric indicators of children  and  adolescents over time , although they appear to be effective in promoting positive changes in the eating habits of this population .
CONCLUSION Intervention programs based only on counseling are effective in promoting changes in dietary patterns , but show poor results in the changes of anthropometric parameters of children and adolescents