***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: CONTEXT Popular diets , particularly those low in carbohydrates , have challenged current recommendations advising a low-fat , high-carbohydrate diet for weight loss . Potential benefits and risks have not been tested adequately . OBJECTIVE To compare 4 weight-loss diets representing a spectrum of low to high carbohydrate intake for effects on weight loss and related metabolic variables . DESIGN , SETTING , AND PARTICIPANTS Twelve-month r and omized trial conducted in the United States from February 2003 to October 2005 among 311 free-living , overweight/obese ( body mass index , 27 - 40 ) nondiabetic , premenopausal women . INTERVENTION Participants were r and omly assigned to follow the Atkins ( n = 77 ) , Zone ( n = 79 ) , LEARN ( n = 79 ) , or Ornish ( n = 76 ) diets and received weekly instruction for 2 months , then an additional 10-month follow-up . MAIN OUTCOME MEASURES Weight loss at 12 months was the primary outcome . Secondary outcomes included lipid profile ( low-density lipoprotein , high-density lipoprotein , and non-high-density lipoprotein cholesterol , and triglyceride levels ) , percentage of body fat , waist-hip ratio , fasting insulin and glucose levels , and blood pressure . Outcomes were assessed at months 0 , 2 , 6 , and 12 . The Tukey studentized range test was used to adjust for multiple testing . RESULTS Weight loss was greater for women in the Atkins diet group compared with the other diet groups at 12 months , and mean 12-month weight loss was significantly different between the Atkins and Zone diets ( P<.05 ) . Mean 12-month weight loss was as follows : Atkins , -4.7 kg ( 95 % confidence interval [ CI ] , -6.3 to -3.1 kg ) , Zone , -1.6 kg ( 95 % CI , -2.8 to -0.4 kg ) , LEARN , -2.6 kg ( -3.8 to -1.3 kg ) , and Ornish , -2.2 kg ( -3.6 to -0.8 kg ) . Weight loss was not statistically different among the Zone , LEARN , and Ornish groups . At 12 months , secondary outcomes for the Atkins group were comparable with or more favorable than the other diet groups . CONCLUSIONS In this study , premenopausal overweight and obese women assigned to follow the Atkins diet , which had the lowest carbohydrate intake , lost more weight at 12 months than women assigned to follow the Zone diet , and had experienced comparable or more favorable metabolic effects than those assigned to the Zone , Ornish , or LEARN diets [ corrected ] While questions remain about long-term effects and mechanisms , a low-carbohydrate , high-protein , high-fat diet may be considered a feasible alternative recommendation for weight loss . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00079573 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 Few studies have examined the weight-control practice s that promote weight loss and weight-loss maintenance in the same sample . PURPOSE To examine whether the weight control practice s associated with weight loss differ from those associated with weight-loss maintenance . METHODS Cross-sectional survey of a r and om sample of 1165 U.S. adults . The adjusted associations of the use of 36 weight-control practice s in the past week with success in weight loss ( ≥10 % lost in the past year ) and success in weight-loss maintenance ( ≥10 % lost and maintained for ≥1 year ) were examined . RESULTS Of the 36 practice s , only 8 ( 22 % ) were associated with both weight loss and weight-loss maintenance . Overall , there was poor agreement ( kappa=0.22 ) between the practice s associated with weight loss and /or weight-loss maintenance . For example , those who reported more often following a consistent exercise routine or eating plenty of low-fat sources of protein were 1.97 ( 95 % CI=1.33 , 2.94 ) and 1.76 ( 95 % CI=1.25 , 2.50 ) times more likely , respectively , to report weight-loss maintenance but not weight loss . Alternatively , those who reported more often doing different kinds of exercises or planning meals ahead of time were 2.56 ( 95 % CI=1.44 , 4.55 ) and 1.68 ( 95 % CI=1.03 , 2.74 ) times more likely , respectively , to report weight loss but not weight-loss maintenance . CONCLUSIONS Successful weight loss and weight-loss maintenance may require two different sets of practice s. Design ing interventions with this premise may inform the design of more effective weight-loss maintenance interventions Objective : The purpose of this study was to compare the dietary strategies , and use of fat- and sugar-modified foods and beverages in a  weight loss maintainer group ( WLM ) and an always-normal weight group (NW).Subjects : WLM ( N=172 ) had maintained ⩾10 % weight loss for 11.5 years , and had a body mass index ( BMI ) of 22.0 kg m−2 . NW ( N=131 ) had a BMI of 21.3 kg m−2 and no history of being overweight . Three , 24-h recalls on r and om , non-consecutive days were used to assess dietary intake . Results : WLM reported consuming a diet that was lower in fat ( 28.7 vs 32.6 % , P<0.0001 ) and used more fat-modification strategies than NW . WLM also consumed a significantly greater percentage of modified dairy ( 60 vs 49 % ; P=0.002 ) and  modified dressings and sauces  ( 55 vs 44 % ; P=0.006 ) than NW . WLM reported consuming three times more daily servings of artificially sweetened soft drinks ( 0.91 vs 0.37 ; P=0.003 ) , significantly fewer daily servings of sugar-sweetened soft drinks ( 0.07 vs 0.16 ; P=0.03 ) and more daily servings of water ( 4.72 vs 3.48 ; P=0.002 ) than NW . Conclusions : These findings suggest that WLM use more dietary strategies to accomplish their weight loss maintenance , including greater restriction on fat intake , use of fat- and sugar-modified foods , reduced consumption of sugar-sweetened beverages and increased consumption of artificially sweetened beverages . Ways to promote the use of fat-modified foods and artificial sweeteners merits further research in both prevention- and treatment-controlled trials Objective : To measure the effect on hydration of two regimens , one that included drinking water as part of the dietary beverages and one that did not . Methods : In healthy , sedentary subjects , two different diets were evaluated for their effect on hydration . Trial A provided plain water to drink as part of the beverages served . Trial B omitted plain water from the beverages served . Twenty-seven males , during two three-day confinement periods , consumed one of two diets in a r and om , crossover and counterbalanced fashion , while diet , physical activity and environment were controlled and monitored . Body weight and 24-hour urine volumes were measured . Pre- and post-trial urine sample s and 24-hour urines were assayed for osmolality , specific gravity , chloride , sodium and potassium , and sodium/potassium ratio was calculated . Twenty-four hour creatinine levels were determined . Results : No differences ( p > 0.05 ) were found between trials for body weight or other indicators of hydration status measured . Conclusions : Inclusion of plain drinking water compared to exclusion of plain drinking water in the diet did not affect the markers of hydration used in this study 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 CONTEXT A recent study reported that drinking 500 ml of water causes a 30 % increase in metabolic rate . If verified , this previously unrecognized thermogenic property of water would have important implication s for weight-loss programs . However , the concept of a thermogenic effect of water is controversial because other studies have found that water drinking does not increase energy expenditure . OBJECTIVE The objective of the study was to test whether water drinking has a thermogenic effect in humans and , furthermore , determine whether the response is influenced by osmolality or by water temperature . DESIGN This was a r and omized , crossover design . SETTING The study was conducted at a university physiology laboratory . PARTICIPANTS Participants included healthy young volunteer subjects . INTERVENTION Intervention included drinking 7.5 ml/kg body weight ( approximately 518 ml ) of distilled water or 0.9 % saline or 7 % sucrose solution ( positive control ) on different days . In a subgroup of subjects , responses to cold water ( 3 C ) were tested . MAIN OUTCOME MEASURE Resting energy expenditure , assessed by indirect calorimetry for 30 min before and 90 min after the drinks , was measured . RESULTS Energy expenditure did not increase after drinking either distilled water ( P = 0.34 ) or 0.9 % saline ( P = 0.33 ) . Drinking the 7 % sucrose solution significantly increased energy expenditure ( P < 0.0001 ) . Drinking water that had been cooled to 3 C caused a small increase in energy expenditure of 4.5 % over 60 min ( P < 0.01 ) . CONCLUSIONS Drinking distilled water at room temperature did not increase energy expenditure . Cooling the water before drinking only stimulated a small thermogenic response , well below the theoretical energy cost of warming the water to body temperature . These results cast doubt on water as a thermogenic agent for the management of obesity Maintenance of weight loss remains a challenge for most individuals . Thus , practical and effective weight-loss maintenance ( WTLM ) strategies are needed . A two-group 12-month WTLM intervention trial was conducted from June 2007 to February 2010 to determine the feasibility and effectiveness of a WTLM intervention for older adults using daily self-monitoring of body weight , step count , fruit/vegetable ( F/V ) intake , and water consumption . Forty weight-reduced individuals ( mean weight lost=6.7±0.6 kg ; body mass index [ calculated as kg/m² ] 29.2±1.1 ) , age 63±1 years , who had previously participated in a 12-week r and omized controlled weight-loss intervention trial , were instructed to record daily body weight , step count , and F/V intake ( WEV [ defined as weight , exercise , and F/V ] ) . Experimental group ( WEV+ ) participants  were also instructed to consume 16 fl oz of water before each main meal ( ie , three times daily ) , and to record daily water intake . Outcome measures included weight change , diet/physical activity behaviors , theoretical constructs related to health behaviors , and other clinical measures . Statistical analyses included growth curve analyses 
    Output:
    
Studies of individuals dieting for weight loss or maintenance suggest a weight-reducing effect of increased water consumption , whereas studies in general mixed-weight population s yielded inconsistent results .