Network meta- analysis revealed that in adolescents , intervention with 2000 mg/day metformin ranked better than other interventions ; however , 1000 mg/day metformin for 3 months may be most suitable for adolescents .
For adults , metformin at doses of 3000 and 1000 mg/day ranked the highest , other than minimeal and lifestyle interventions ; moreover , intervention with 3000 mg/day for 6 months and 1000 mg/day for 0.5 months may be suitable for adults .
Conclusion When considering the efficacy of interventions for losing weight , metformin offers clear advantages for overweight and obese population
Purpose Our aim was to assess the efficacy of metformin for weight loss in overweight and obese people through a systematic review and network meta- analysis and to identify the most suitable dosage and intervention period for using metformin  in adolescents and adults .
Metformin and placebo therapy both improve weight management and fasting insulin in obese insulin-resistant adolescents: a prospective, placebo-controlled, randomized study.
OBJECTIVE To study whether metformin reduces obesity , homeostasis model assessment for insulin resistance index ( HOMA-IR ) , and the metabolic syndrome ( MtS ) in obese European adolescents in addition to previous unsuccessful lifestyle intervention . DESIGN AND METHODS After 6 months of multiprofessional lifestyle intervention , 70 out of 86 adolescents without improvement in body mass index ( BMI ) and HOMA-IR  were r and omized into either the placebo ( n=34 ) or the metformin group ( 2 × 500 mg/day , n=36 ) in addition to ongoing lifestyle intervention for another 6 months . RESULTS Age was 13.8 years , BMI was 33.1 kg/m(2 ) , 65 % were female , and 89 % were Caucasians . During lifestyle intervention alone , BMI and HOMA-IR deteriorated significantly . In the subsequent medication period , HOMA-IR and fasting insulin improved similarly in the placebo and metformin groups ( HOMA-IR decreased 73 vs 54 % respectively in metformin versus placebo ; P=0.048 ) , but BMI remained unchanged . The insulin sensitivity index , however , only improved in the metformin group . High fasting insulin is correlated with a subsequent BMI increase irrespective of the medication . MtS remained unchanged . CONCLUSIONS Obese European adolescents '  insulin sensitivity improved without weight change during placebo or metformin intervention in addition to lifestyle intervention . Most differences did not reach statistical significance , probably due to improved compliance with lifestyle intervention as a placebo effect . In addition , the metformin dose may be too low
Network meta- analysis revealed that in adolescents , intervention with 2000 mg/day metformin ranked better than other interventions ; however , 1000 mg/day metformin for 3 months may be most suitable for adolescents .
For adults , metformin at doses of 3000 and 1000 mg/day ranked the highest , other than minimeal and lifestyle interventions ; moreover , intervention with 3000 mg/day for 6 months and 1000 mg/day for 0.5 months may be suitable for adults .
Conclusion When considering the efficacy of interventions for losing weight , metformin offers clear advantages for overweight and obese population
Purpose Our aim was to assess the efficacy of metformin for weight loss in overweight and obese people through a systematic review and network meta- analysis and to identify the most suitable dosage and intervention period for using metformin  in adolescents and adults .