Research has been very varied , however , daily consumption of green tea with doses of EGCG between 100 and 460 mg/day has shown greater effectiveness on body fat and body weight reduction in intervention periods of 12 weeks or more .
In addition , the use of caffeine doses between 80 and 300 mg/day has been shown to be an important factor for this effects , when the participants did not have a high caffeine intake ( > 300 mg/day ) prior to the intervention
The prevalence and incidence of overweight and obesity worldwide continues to increase , as well as diseases related to these conditions .
This is attributed to an increase in energy intake and a decrease in energy expenditure .
Consumption of green tea has been linked to a reduction in body fat and body weight .
However , research on green tea has been very diverse .
This review assesses the investigations that have been made with green tea and its epigallocatechin gallato ( EGCG ) content , evaluating its effect on body fat and body weight in humans .
Long-Term Supplementation of Green Tea Extract Does Not Modify Adiposity or Bone Mineral Density in a Randomized Trial of Overweight and Obese Postmenopausal Women.
BACKGROUND Green tea extract ( GTE ) consumption has been linked to favorable changes in adiposity and bone mineral density ( BMD ) , although it is unknown if these effects are due to green tea catechins or caffeine . The catechol-O-methyltransferase ( COMT ) genotype may also modify these associations . OBJECTIVE We examined the impact of decaffeinated GTE on body composition ( using dual-energy X-ray absorptiometry ) and obesity-associated hormones . METHODS The Minnesota Green Tea Trial was a 12-mo r and omized , double-blind , placebo-controlled clinical trial in 937 postmenopausal women ( aged 50 - 70 y ) assigned to receive either GTE containing 843 mg (-)-epigallocatechin-3-gallate or placebo . This sub study was conducted in 121 overweight/obese participants [ body mass index ( BMI ) ( kg/m(2 ) ) ≥25.0 ] . RESULTS There were no differences in changes in BMI ( -0.13 ± 0.11 compared with -0.05 ± 0.11 ; P = 0.61 ) , total fat mass ( -0.30 ± 0.16 compared with -0.12 ± 0.15 kg ; P = 0.40 ) , percentage of body fat ( -0.15 % ± 0.17 % compared with -0.15 % ± 0.16 % ; P = 0.99 ) , or BMD ( -0.006 ± 0.002 compared with -0.003 ± 0.002 g/cm(2 ) ; P = 0.49 ) over 12 mo between women taking GTE ( n = 61 ) and those taking a placebo ( n = 60 ) . Interactions were observed between treatment and time for gynoid percentage of fat ( % fat ) and tissue % fat . Gynoid % fat increased from baseline to month 12 in the placebo group as baseline BMI increased and decreased over time as baseline BMI increased in the GTE group ( P-interaction = 0.02 ) . Tissue % fat increased from baseline to month 12 in the placebo group as baseline BMI increased . In the GTE  group , tissue % fat decreased during the intervention as baseline BMI increased ( P-interaction = 0.04 ) . No changes were seen in circulating leptin , ghrelin , adiponectin , or insulin concentrations . COMT genotype did not modify the effect of GTE on any variable . CONCLUSIONS Decaffeinated GTE was not associated with overall reductions in adiposity or improvements in BMD in overweight/obese postmenopausal women . However , GTE may be beneficial for reduction in tissue and gynoid % fat in individuals with higher BMI . This clinical trial was registered at www . clinical trials.gov as NCT00917735
Research has been very varied , however , daily consumption of green tea with doses of EGCG between 100 and 460 mg/day has shown greater effectiveness on body fat and body weight reduction in intervention periods of 12 weeks or more .
In addition , the use of caffeine doses between 80 and 300 mg/day has been shown to be an important factor for this effects , when the participants did not have a high caffeine intake ( > 300 mg/day ) prior to the intervention
The prevalence and incidence of overweight and obesity worldwide continues to increase , as well as diseases related to these conditions .
This is attributed to an increase in energy intake and a decrease in energy expenditure .
Consumption of green tea has been linked to a reduction in body fat and body weight .
However , research on green tea has been very diverse .
This review assesses the investigations that have been made with green tea and its epigallocatechin gallato ( EGCG ) content , evaluating its effect on body fat and body weight in humans .