Takase 2008.

Methods	This was a randomised, double‐blind, placebo‐controlled, parallel‐group clinical trial with a randomisation ratio of 1:1.06
Participants	INCLUSION CRITERIA: Japanese women 40 to 55 years old visceral fat area of ≥ 85 cm2 BMI: 25 to 30 kg/m2 EXCLUSION CRITERIA: undergoing medical treatment severe kidney, liver, heart disease or diabetes possibility of becoming pregnant during the course of the study those judged unsuitable by head doctor DIAGNOSTIC CRITERIA: height weight  BMI (calculated from previous 2 measurements) abdominal fat CT (cross‐sectional CT scans taken between L4 and L5 vertebrae at ‐2 weeks and at week 12; CT images taken with tube voltage at 120 kVp, 240 mAs, on inhale; film output done with window level = 0 and window width = 1000 using visceral fat measuring software Fat Scan vers. 2 (N2 System Co., Osaka, Japan) to measure total fat area (TFA), visceral fat area (VFA) and subcutaneous fat area (SFA)
Interventions	NUMBER OF STUDY CENTRES: NR ("multi‐facility") COUNTRY/ LOCATION: Japan SETTING: NR TREATMENT BEFORE STUDY: unknown
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 Japanese in the journal Japanese Pharmacology & Therapeutics, and all 6 authors are affiliated with Kao Corporation in the Health Care Food Research Laboratories; no sources of funding were reported
Stated aim of study	Quote from study: "the present study used visceral fat area measured in CT scans as a criterion for the selection of study participants to investigate the effects of daily consumption of a high‐dose tea catechin beverage on visceral fat and metabolic syndrome in obese females with large accumulations of visceral fat"
Notes	BMI: body Mass Index; CT: computerised axial tomography; NR: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote from study: "this study was implemented as a multi‐facility, randomised, double‐blind, placebo‐controlled, parallel‐group trial" "based on the preliminary exam, participants were randomly assigned to either the catechin or the placebo group" "in this study, 101 individuals selected to participate as a result of prior screening were then randomly divided into two groups" Comment: method of randomisation not reported
Allocation concealment (selection bias)	Unclear risk	Comment: not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote from study: "the catechin beverage and placebo beverage were flavoured to taste like a sports drink and except for their catechin content were formulated in the same way" Comment: 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