Nagao 2007.

Methods	This trial was a randomised, double‐blind, controlled parallel clinical study with a randomisation ratio of 1:1
Participants	INCLUSION CRITERIA: 25 to 55 year old BMI 24 to 30 kg/m2, waist circumference of 80 to 94 cm (considered to be visceral fat‐type obese), or both EXCLUSION CRITERIA: treated at an outpatient department serious liver disease serious renal disease DIAGNOSTIC CRITERIA: height weight BMI (calculated from the previous 2 measurements) waist circumference (circumference at the umbilical level)
Interventions	NUMBER OF STUDY CENTRES: 7 COUNTRY/ LOCATION: Japan/ Kanto district SETTING: medical institutions TREATMENT BEFORE STUDY: note: 2‐week run‐in period
Outcomes	OUTCOME(S) (as stated in the protocol/registered trial documents): PRIMARY OUTCOME(S): unknown SECONDARY OUTCOME(S): unknown OTHER OUTCOME(S): unknown
Study details	STUDY TERMINATED BEFORE REGULAR END: no
Publication details	This study was published in English in Obesity, a peer‐reviewed journal, and did not receive funding or outside support. The lead author is affiliated with Health Care Food Research Laboratories, Kao Corporation in Tokyo, Japan
Stated aim of study	Quote from study: "therefore, the present trial was conducted to clarify the body fat reducing effect of the continuous ingestion of a green tea extract (GTE) high in catechins in more than 200 Japanese women and men who were maintaining their usual lifestyles. We also examined the effects of a GTE high in catechins on risk factors of cardiovascular disease"
Notes	BMI: body mass index
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote from study: "this was a randomised double‐blind, controlled parallel multicenter trial" "randomisation was stratified by gender and BMI measured at the time of the run‐in period at each institution" Comment: method of randomisation not reported
Allocation concealment (selection bias)	Unclear risk	Quote from study: "after the run‐in period, the subjects were allocated into two groups" Comment: allocation concealment not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote from study: "this was a randomised double‐blind, controlled parallel multicenter trial" Comment: no description of GTE product compared to placebo found, other than that the base for both was brewed green tea. No mention of effectiveness of blinding efforts. No mention of whether researchers and staff were blinded to study components
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: all outcomes on which the study reported were objective and measured by assessors. Therefore, whether or not assessors were blinded, risk of detection bias was assessed as low
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: authors adequately accounted for attrition
Selective reporting (reporting bias)	Low risk	Comment: outcomes specified at the beginning were adequately investigated and reported
Other bias	Low risk	Comment: appears to be free of other bias