Maki 2009.

Methods	This was a randomised, placebo‐controlled, double‐blind trial, with a treatment to control randomisation ratio of 1:0.97
Participants	INCLUSION CRITERIA: 21 to 65 year old waist circumference ≥ 87 cm (women) or ≥ 90 cm (men) total cholesterol (total‐C) ≥ 5.2 mmol/L at screening agreement to consume no more than 2 caffeinated beverages per day, not including the study product, and no over‐the‐counter supplements or medications containing caffeine were allowed EXCLUSION CRITERIA: pregnant or lactating women or those planning to become pregnant BMI < 25.0 kg/m2 or ≥ 40.0 kg/m2 recent weight loss of > 4.5 kg recent use of any weight loss medications, supplements or programmes a history of weight‐reducing surgery any history of eating disorders any indication that unsupervised physical activity was inadvisable DIAGNOSTIC CRITERIA: waist circumference (measured on horizontal plane at iliac crest using a non‐stretch anthropometric tape at end of normal expiration) total cholesterol (measurements from blood samples taken in fasted state)
Interventions	NUMBER OF STUDY CENTRES: 2 COUNTRY/ LOCATION: USA/Provident Clinical Research (Bloomington, IN) and Merithen Research (St Petersburg, FL) SETTING: clinical research sites TREATMENT BEFORE STUDY: unknown
Outcomes	OUTCOME(S) (as stated in the protocol/registered trial documents): PRIMARY OUTCOME(S): changes in body fat mass SECONDARY OUTCOME(S): changes in body weight OTHER OUTCOME(S): NR
Study details	STUDY TERMINATED BEFORE REGULAR END: no
Publication details	This study was published in English in The Journal of Nutrition, a peer‐reviewed journal, and was supported by Kao Corporation in Tokyo, Japan
Stated aim of study	Quote from study: "the present study was designed to evaluate the effects of a green tea catechin‐containing beverage on body composition and fat distribution in overweight and obese adults in the United States during exercise‐induced weight loss"
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 clinical trial" Comment: method of randomisation not reported
Allocation concealment (selection bias)	Unclear risk	Comment: not reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote from study: "study beverages were packaged in identical, single‐serving containers. The study products were labelled and coded in such a manner that subjects and staff were unaware of which product each participant was receiving. The beverages had similar sensory characteristics. Internal pretrial testing showed no difference in preference or palatability ratings between the active and control beverages" Comment: no mention of effectiveness of blinding efforts
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: the attrition in this study was higher than in most (84% in intervention and 79% in controlled group completed the study). Authors adequately accounted for attrition. However, the reasons for not completing the study were adequately described with the exception of participants who were lost to follow up (similar number in both groups). Therefore, we assessed the risk of bias as low.
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