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 .
Effect of metformin on glucagon-like peptide 1 (GLP-1) and leptin levels in obese nondiabetic subjects.
OBJECTIVE To evaluate the effects of metformin on glucagon-like peptide 1 ( GLP-1 ) and leptin levels . RESEARCH DESIGN AND METHODS A total of 10 obese nondiabetic male patients were studied before and after a 14-day treatment with 2,550 mg/day metformin and were compared with 10 untreated obese control subjects . On days 0 and 15 , leptin and GLP-1(7 - 36)amide/(7 - 37 ) levels were assessed before and after an oral glucose load during a euglycemic hyperinsulinemic clamp to avoid the interference of variations of insulinemia and glycemia on GLP-1 and leptin secretion . The effects of metformin on GLP-1(7 - 36)amide degradation in human plasma and in a buffer solution containing dipeptidyl peptidase IV ( DPP-IV ) were also studied . RESULTS Leptin levels were not affected by the oral glucose load , and they were not modified after metformin treatment . Metformin induced a significant ( P < 0.05 ) increase of GLP-1(7 - 36)amide/(7 - 37 ) at 30 and 60 min after the oral glucose load ( 63.8 + /- 29.0 vs. 50.3 + /- 15.6 pmol/l and 75.8 + /- 35.4 vs. 46.9 + /- 20.0 pmol/l , respectively ) , without affecting baseline GLP-1 levels . No variations of GLP-1 levels were observed in the control group . In pooled human plasma , metformin ( 0.1 - 0.5 microg/ml ) significantly inhibited degradation of GLP-1(7 - 36)amide after a 30-min incubation at 37 degrees C ; similar results were obtained in a buffer solution containing DPP-IV . CONCLUSIONS Metformin significantly increases GLP-1 levels after an oral glucose load in obese nondiabetic subjects ; this effect could be due to an inhibition of GLP-1 degradation
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 .