***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 Little is known about how the intensity of exercise influences cardiovascular fitness and body composition , especially in obese adolescents . OBJECTIVE Our goal was to determine the effects of physical training intensity on the cardiovascular fitness , percentage of body fat ( % BF ) , and visceral adipose tissue ( VAT ) of obese adolescents . DESIGN Obese 13 - 16-y-olds ( n = 80 ) were assigned to 1 ) biweekly lifestyle education ( LSE ) , 2 ) LSE + moderate-intensity physical training , or 3 ) LSE + high-intensity physical training . The intervention lasted 8 mo . Physical training was offered 5 d/wk , and the target energy expenditure for all subjects in physical training groups was 1047 kJ ( 250 kcal)/session . Cardiovascular fitness was measured with a multistage treadmill test , % BF with dual-energy X-ray absorptiometry , and VAT with magnetic resonance imaging . RESULTS The increase in cardiovascular fitness in the high-intensity physical training group , but not in the moderate-intensity group , was significantly greater than that in the LSE alone group ( P = 0.009 ) ; no other comparisons of the 3 groups were significant . Compared with the LSE alone group , a group composed of subjects in both physical training groups combined who attended training sessions > or=2 d/wk showed favorable changes in cardiovascular fitness ( P < 0.001 ) , % BF ( P = 0.001 ) , and VAT ( P = 0.029 ) . We found no evidence that the high-intensity physical training was more effective than the moderate-intensity physical training in enhancing body composition . CONCLUSIONS The cardiovascular fitness of obese adolescents was significantly improved by physical training , especially high-intensity physical training . The physical training also reduced both visceral and total-body adiposity , but there was no clear effect of the intensity of physical training OBJECTIVE A r and omized controlled trial tested the efficacy of an internet-based lifestyle behavior modification program for African-American girls over a 2-year period of intervention . RESEARCH METHODS AND PROCEDURES Fifty-seven overweight ( mean BMI percentile , 98.3 ) African-American girls ( mean age , 13.2 years ) were r and omly assigned to an interactive behavioral internet program or an internet health education program , the control condition .  Overweight parents were also participants in the study . Forty adolescent-parent dyads ( 70 % ) completed the 2-year trial . Outcome data including BMI , body weight , body composition , and weight loss behaviors were collected at baseline and at 6-month intervals . A computer server tracked use of the web sites . RESULTS An intention-to-treat statistical approach was used , with the last observation carried forward . In comparison with the control condition , adolescents in the behavioral program lost more mean body fat ( BF ) ( -1.12 + /- 0.47 % vs. 0.43 + /- 0.47 % BF , p < 0.05 ) , and parents in the behavioral program lost significantly more mean body weight ( -2.43 + /- 0.66 vs. -0.35 + /- 0.64 kg , p < 0.05 ) during the first 6 months . This weight loss was regained over the next 18 months . After 2 years , differences in fat for adolescents ( -0.08 + /- 0.71 % vs. 0.84 + /- 0.72 % BF ) and weight for parents ( -1.1 + /- 0.91 vs. -0.60 + /- 0.89 kg ) did not differ between the behavioral and control programs . DISCUSSION An internet-based weight management program for African-American adolescent girls and their parents result ed in weight loss during the first 6 months but did not yield long-term loss due to reduced use of the web site over time Objective : Since peers have such an important influence on adolescents , we evaluated the efficacy of adding peer-based ‘ adventure therapy ’ to a st and ard cognitive-behavioral weight control program for overweight adolescents . Methods : Adolescents ( N=76 ) aged 13–16 years and 20 to 80 % overweight ( M=60.56 % , s.d.=15.17 % ) , were r and omly assigned to one of two treatment conditions : cognitive-behavioral group treatment with ‘ adventure therapy ’ similar to Outward Bound ® ( cognitive-behavioral treatment with peer-enhanced adventure therapy ( CBT+PEAT ) ) or cognitive-behavioral group treatment with aerobic exercise ( CBT+EXER ) . Anthropometric and psychosocial measures were obtained at baseline , at the end of the 16-week intervention , and at 10 months following r and omization . Results : Adolescents assigned to both treatment conditions demonstrated significant weight loss over time , F=29.06 , df=2 , 53 , P<0.01 . Average weight loss did not differ significantly between groups ( −5.31 kg for CBT+PEAT and −3.20 kg for CBT+EXER ) at the end of treatment . There was a significant difference in the percentage of participants maintaining a minimum 4.5 kg ( 10 pounds ) weight loss ( 35 % in the CBT+PEAT condition vs 12 % in the CBT+EXER condition , P=0.042 ) 10 months from r and omization . We also observed a significant age by treatment group interaction , such that older adolescents r and omized to CBT+PEAT demonstrated more than four times the weight loss of older adolescents assigned to CBT+EXER ( M=−7.86 kg vs M=−1.72 kg ) at the end of treatment . Conclusions : Peer-based ‘ adventure therapy ’ is a promising adjunct to st and ard cognitive-behavioral weight control intervention for adolescents , and may be most effective for older adolescents OBJECTIVES The primary goals were to underst and the relationship among the inflammatory factors , C-reactive protein ( CRP ) , interleukin-6 ( IL-6 ) , and fibrinogen , and indices of obesity in normoglycemic , insulin-resistant adolescents and to investigate the impact of a lifestyle-only intervention on these nontraditional risk factors for cardiovascular disease ( CVD ) . STUDY DESIGN R and omized controlled lifestyle-only intervention study in adolescents . Of the 21 adolescents studied , 15 obese subjects ( body mass index [ BMI ] = 37.6 + /- 3.3 kg/m 2 ) were r and omized to either a lifestyle intervention program or usual care .  The lean controls were studied only at baseline . Analysis of variance ( ANOVA ) for repeated measures was used to study intervention effect and t test , one-way ANOVA , and discriminant function analysis for baseline comparisons . RESULTS The intervention group maintained weight , whereas the control group gained weight ( P = .02 ) . A redistribution of body composition and a decrease in insulin resistance were observed . Elevated circulating concentrations of CRP , fibrinogen , and IL-6 were significantly reduced ( all P < or=.02 ) in response to intervention , but not in controls . CONCLUSIONS Modest lifestyle-only change in previously sedentary obese adolescents redistributes the parameters of body composition in the absence of weight loss and reverses , at least in part , the inflammatory state in association with an improvement of insulin resistance The leisure-time physical activity  of 13-year-old Finnish adolescents was assessed in the prospect i ve STRIP study . A self-administered question naire ( N=565 ) was used . The leisure-time physical activity index ( PAI ; MET h/week ) was calculated on the basis of reported exercise intensity , duration and frequency ( N=558 ; 53 % boys ) . The participants were divided into Sedentary , Moderately Active and Active groups by PAI tertiles . A sub population ( N=197 ) also used a heart rate monitor ( 3 days , > /=8 h/day ) to assess the time spent on different activity intensities . The median male PAI was 31.3 ( inter-quartile range ( IQR ) 44.2 ) MET h/week and female 19.5 ( IQR 26.3 ) MET h/week ( P=0.0002 ) . The cutoff points of the PAI tertiles were similar for the Active girls ( 31.3 MET h/week ) and boys ( 32.6 MET h/week ) , but for the Sedentary boys it was 19.5 MET h/week and only 5.0 MET h/week for the Sedentary girls . High self-reported leisure-time physical activity associated poorly with time spent on moderate or vigorous exercise measured by heart rate monitoring . Active mothers had more often Active daughters or sons . In conclusion , the amount of leisure-time physical activity of one-third of 13-year-old girls is extremely low . Sedentary adolescents , especially girls , should therefore be put into focus for active efforts to increase their leisure-time physical activity . Parental models may be important Background : Childhood obesity has become a nutritional problem in China since the 1990s . Aims : A family based behavioural treatment was developed and tested , to see if its use was feasible in China and to evaluate its impact on obese schoolchildren . Methods : In a single school in Beijing , 33 obese children were r and omly assigned to a treatment group and 35 to a control group . The treatment group participated in a family based behavioural treatment programme for two years . Height and weight were measured every six months for all participants . Blood pressure , cholesterol , and triglyceride levels were measured at baseline and after two years of programme implementation . Results : Body mass index ( BMI , kg/m2 ) was significantly reduced in the treatment group ( from 26.6 ( 1.7 ) to 24.0 ( 0.9 ) , 95 % CI 2.06 to 3.18 ) but not in the control group ( from 26.1 ( 1.5 ) to 26.0 ( 1.6 ) ) . Total cholesterol decreased 5.5 % and triglycerides 9.7 % in the treatment group . There was a significant correlation between change in BMI and change in triglycerides . There were no significant changes in plasma lipids in the controls . Blood pressure values also decreased significantly in the treatment , but not the control group . Conclusions : A family based behavioural intervention was feasible to use in treating obesity in schoolchildren in Beijing , China . After two years of implementation , it successfully decreased the degree of obesity , reduced levels of blood pressure , and decreased serum lipids in treatment ; there were no significant changes among control children The purpose s of this article are to present an overview of r and omized clinical trials ( RCTs ) and describe some of the method ological problems inherent in using RCTs in nursing research . Many nursing intervention studies are fraught with problems that defy the stringent control criteria required for RCTs , leading to biased estimates of intervention efficacy . Five threats to validity in RCTs are presented , including problems related to ( a ) differential dropout , ( b ) r and om assignment , ( c ) identifying and maintaining an adequate control condition , ( d ) nonadherence to research protocol s , and ( e ) assessment of clinical ly meaningful change . Three strategies are recommended for addressing some of the problems posed by RCTs and improving inference Recent findings indicate that nearly 50 % of black American women are obese and that adolescence is a critical period for the development of their obesity . This study investigated the efficacy of a behavioral weight control program in 36 black female adolescents with a mean age of 14.0 years , weight of 95.0 kg , and height of 163.2 cm . All subjects participated in the same 16-week program but had different levels of parent participation : ( 1 ) child alone with no parent participation ; ( 2 ) mother and child treated in the same session ; and ( 3 ) mother and child treated in separate but concurrent session . At the end of the 16-week program , children in the three conditions lost 1.6 , 3.7 , and 3.1 kg , respectively . Differences among conditions were not statistically significant ; however , a secondary analysis revealed that the greater the number of sessions attended by mothers , the greater their daughters ' weight losses . Weight reduction was associated with significant improvements in body composition , serum total cholesterol concentrations , and psychological status . Results are discussed in terms of the need to improve the maintenance of weight loss in adolescents and to explore possible differences between black and white females in their preferred body types The effectiveness of the  adolescent obesity intervention SHAPEDOWN was evaluated for 15 months through a r and omized experimental design study . Test groups ( no. = 37 ) participating in the intervention were compared with a no-treatment control group ( no. = 29 ) at four sites in northern California . The program employs a variety of cognitive , behavioral , and affective techniques adapted to make successive small modifications in diet , exercise , communication , and affect that are sustainable . Very-low-calorie or restrictive diets are avoided in the program . Parents are instructed on strategies for supporting their adolescents ' weight-loss efforts . Participation in the group application of the program was associated with significant improvement in relative weight , weight-related behavior , depression , and knowledge of weight management concepts at post-treatment and at 1-year follow-up . Self-esteem increased significantly regardless of condition . Change in relative weight for the test group was -9.9 + /- 14.9 % ( mean + /- st and ard deviation ) and for the control group was -0.10 + /- 13.2 % . At month 15 of the study period , weight change in the test group 
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RESULTS Due to a lack of consistency among the studies regarding methods and rigor of the studies , the evidence is not entirely clear on the best multicomponent program for addressing overweight in middle adolescents .
The success of an intervention was associated with the dose of the intervention received by the adolescent and parent .
A structured program addressing nutrition , physical activity , and behavioral skills appears to be efficacious in reducing weight and cardiovascular risk factors .