***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: OBJECTIVE . The study tested whether a combined environmental and educational intervention solely promoting water consumption was effective in preventing overweight among children in elementary school . METHODS . The participants in this r and omized , controlled cluster trial were second- and third- grade rs from 32 elementary schools in socially deprived areas of 2 German cities .  Water fountains were installed and teachers presented 4 prepared classroom lessons in the intervention group schools ( N = 17 ) to promote water consumption .  Control group schools ( N = 15 ) did not receive any intervention . The prevalence of overweight ( defined according to the International Obesity Task Force criteria ) , BMI SD scores , and beverage consumption ( in glasses per day ; 1 glass was defined as 200 mL ) self-reported in 24-hour recall question naires , were determined before ( baseline ) and after the intervention . In addition , the water flow of the fountains was measured during the intervention period of 1 school year ( August 2006 to June 2007 ) . RESULTS . Data on 2950 children ( intervention group : N = 1641 ; control group : N = 1309 ; age , mean ± SD : 8.3 ± 0.7 years ) were analyzed . After the intervention , the risk of overweight was reduced by 31 % in the intervention group , compared with the control group , with adjustment for baseline prevalence of overweight and clustering according to school . Changes in BMI SD scores did not differ between the intervention group and the control group . Water consumption after the intervention was 1.1 glasses per day greater in the intervention group . No intervention effect on juice and soft drink consumption was found . Daily water flow of the fountains indicated lasting use during the entire intervention period , but to varying extent . CONCLUSION . Our environmental and educational , school-based intervention proved to be effective in the prevention of  overweight among children in elementary school , even in a population from socially deprived areas BACKGROUND The consumption of beverages that contain sugar is associated with overweight , possibly because liquid sugars do not lead to a sense of satiety , so the consumption of other foods is not reduced . However , data are lacking to show that the replacement of sugar-containing beverages with noncaloric beverages diminishes weight gain . METHODS We conducted an 18-month trial involving 641 primarily normal-weight children from 4 years 10 months to 11 years 11 months of age . Participants were r and omly assigned to receive 250 ml ( 8 oz ) per day of a sugar-free , artificially sweetened beverage ( sugar-free group ) or a similar sugar-containing beverage that provided 104 kcal ( sugar group ) . Beverages were distributed through schools . At 18 months , 26 % of the children had stopped consuming the beverages ; the data from children who did not complete the study were imputed . RESULTS The z score for the body-mass index ( BMI , the weight in kilograms divided by the square of the height in meters ) increased on average by 0.02 SD units in the sugar-free group and by 0.15 SD units in the sugar group ; the 95 % confidence interval ( CI ) of the difference was -0.21 to -0.05 . Weight increased by 6.35 kg in the sugar-free group as compared with 7.37 kg in the sugar group ( 95 % CI for the difference , -1.54 to -0.48 ) . The skinfold-thickness measurements , waist-to-height ratio , and fat mass also increased significantly less in the sugar-free group . Adverse events were minor . When we combined measurements at 18 months in 136 children who had discontinued the study with those in 477 children who completed the study , the BMI z score increased by 0.06 SD units in the sugar-free group and by 0.12 SD units in the sugar group ( P=0.06 ) . CONCLUSIONS Masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children . ( Funded by the Netherl and s Organization for Health Research and Development and others ; DRINK Clinical Trials.gov number , NCT00893529 . ) OBJECTIVE : To examine the long-term relationship between changes in water and beverage intake and weight change . SUBJECTS : Prospect i ve cohort studies of 50 013 women aged 40–64 years in the Nurses ’ Health Study ( NHS , 1986–2006 ) , 52 987 women aged 27–44 years in the NHS II ( 1991–2007 ) and 21 988 men aged 40–64 years in the Health Professionals Follow-up Study ( 1986–2006 ) without obesity and chronic diseases at baseline . MEASURES : We assessed the association of weight change within each 4-year interval , with changes in  beverage intakes and other  lifestyle behaviors  during the same period . Multivariate linear regression with robust variance and accounting for within-person repeated measures were used to evaluate the association . Results across the three cohorts were pooled by an inverse-variance-weighted meta- analysis . RESULTS : Participants gained an average of 1.45 kg ( 5th to 95th percentile : −1.87 to 5.46 ) within each 4-year period . After controlling for age , baseline body mass index and changes in other lifestyle behaviors ( diet , smoking habits , exercise , alcohol , sleep duration , TV watching ) , each 1 cup per day increment of water intake was inversely associated with weight gain within each 4-year period ( −0.13 kg ; 95 % confidence interval ( CI ) : −0.17 to −0.08 ) . The associations for other beverages were : sugar-sweetened beverages ( SSBs ) ( 0.36 kg ; 95 % CI : 0.24–0.48 ) , fruit juice ( 0.22 kg ; 95 % CI : 0.15–0.28 ) , coffee ( −0.14 kg ; 95 % CI : −0.19 to −0.09 ) , tea ( −0.03 kg ; 95 % CI : −0.05 to −0.01 ) , diet beverages ( −0.10 kg ; 95 % CI : −0.14 to −0.06 ) , low-fat milk ( 0.02 kg ; 95 % CI : −0.04 to 0.09 ) and whole milk ( 0.02 kg ; 95 % CI : −0.06 to 0.10 ) . We estimated that replacement of 1 serving per day of SSBs by 1 cup per day of water was associated with 0.49 kg ( 95 % CI : 0.32–0.65 ) less weight gain over each 4-year period , and the replacement estimate of fruit juices by water was 0.35 kg ( 95 % CI : 0.23–0.46 ) . Substitution of SSBs or fruit juices by other beverages ( coffee , tea , diet beverages , low-fat and whole milk ) were all significantly and inversely associated with weight gain . CONCLUSION : Our results suggest that increasing water intake in place of SSBs or fruit juices is associated with lower long-term weight gain OBJECTIVE To determine the efficacy of a 2-year obesity prevention program in African American girls . DESIGN Memphis GEMS ( Girls ' health Enrichment Multi-site Studies ) was a controlled trial in which girls were r and omly assigned to an obesity prevention program or alternative intervention . SETTING Local community centers and YWCAs ( Young Women 's Christian Associations ) in Memphis , Tennessee . PARTICIPANTS Girls aged 8 to 10 years ( N = 303 ) who were identified by a parent or guardian as African American and who had a body mass index ( BMI ) at or higher than the 25th percentile for age or 1 parent with a BMI of 25 or higher . INTERVENTIONS Group behavioral counseling to promote healthy eating and increased physical activity ( obesity prevention program ) or self-esteem and social efficacy ( alternative intervention ) . MAIN OUTCOME MEASURE The BMI at 2 years . RESULTS The BMI increased in all girls with no treatment effect ( obesity prevention minus alternative intervention ) at 2 years ( mean , 0.09 ; 95 % confidence interval [ CI ] , -0.40 to 0.58 ) . Two-year treatment effects in the expected direction were observed for servings per day of sweetened beverages ( mean , -0.19 ; 95 % CI , -0.39 to 0.09 ) , water ( mean , 0.21 ; 95 % CI , 0.03 to 0.40 ) , and vegetables ( mean , 0.15 ; 95 % CI,-0.02 to 0.30 ) , but there were no effects on physical activity . Post hoc analyses suggested a treatment effect in younger girls ( P for interaction = .08 ) . The mean BMI difference at 2 years was -2.41 ( 95 % CI , -4.83 to 0.02 ) in girls initially aged 8 years and -1.02 ( 95 % CI , -2.31 to 0.27 ) in those initially aged 10 years . CONCLUSIONS The lack of significant BMI change at 2 years indicates that this intervention alone is insufficient for obesity prevention . Effectiveness may require more explicit behavior change goals and a stronger physical activity component as well as supportive changes in environmental context CONTEXT Recently , we showed that drinking 500 ml water induces thermogenesis in normal-weight men and women . OBJECTIVE We now repeated these studies in a r and omized , controlled , crossover trial in overweight or obese otherwise healthy subjects ( eight men and eight women ) , comparing also the effects of 500 ml isoosmotic saline or 50 ml water . RESULTS Only 500 ml water increased energy expenditure by 24 % over the course of 60 min after ingestion , whereas isoosmotic saline and 50 ml water had no effect . Heart rate and blood pressure did not change in these young , healthy subjects . CONCLUSIONS Our data exclude volume-related effects or gastric distension as the mediator of the thermogenic response to water drinking . Instead , we hypothesize the existence of a portal osmoreceptor , most likely an ion channel 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 OBJECTIVE We examined whether drinking water per se is associated with drinking less of other beverages and whether changes in BMI are associated with the intake of water and other beverages . DESIGN Secondary analysis of a r and omized trial of fourth grade rs followed over 1 year . SETTING Public schools in the metropolitan area of Rio de Janeiro , Brazil . SUBJECTS Participants were 1134 students aged 10 - 11 years . RESULTS At baseline , a higher frequency of water consumption was associated with a greater daily intake of fruit juice  ( P = 0.02 ) and a higher daily frequency of milk ( P = 0.005 ) . In the intervention group , the baseline frequency of water consumption  was negatively associated with weight change over 1 year but without statistical significance ( coefficient = -0.08 kg/m2 ; 95 % CI -0.37 , 0.24 kg/m2 ) , whereas fruit juice intake frequency was positively associated with weight change : each increase in fruit juice intake of 1 glass/d was associated with a BMI increase of 0.16 ( 95 % CI 0.02 , 0.30 ) kg/m2 . CONCLUSIONS Our findings do not support a protective effect of water consumption on BMI , but confirm consumption of juice drinks as a risk factor for BMI gain .  Students who reported high water consumption also reported high intake of other beverages ; therefore , the promotion of water consumption per se would not prevent excessive weight gain Obesity among Saudi youth is a growing public health challenge . This cross-sectional study measured body mass index ( BMI ) and determined the eating habits and lifestyle of 107 r and omly selected female adolescent students ( age  
    Output:
    
On the cross-sectional level , higher water consumption seems to be associated with higher weight status .
In contrast , longitudinal studies suggest a weight-reducing effect of water consumption , but evidence for a causal association is still low