Westerterp‐Plantenga 2005.

Methods	This study was a randomised, double‐blind, placebo‐controlled trial with a parallel design, with a treatment to control randomisation ratio of 1:1
Participants	INCLUSION CRITERIA: male and female 18 to 60 years old BMI 25 to 35 kg/m2 good health non‐smoker moderate alcohol user at most EXCLUSION CRITERIA: using medication DIAGNOSTIC CRITERIA: weight (measured with a digital balance ‐ model 707; Seca, Hamburg, Germany; weighing accuracy of 0.1 kg ‐ participants in underwear, in a fasted state, after emptying their bladder) height (measured with a wall‐mounted stadiometer ‐ model 220; Seca) BMI (calculated from previous 2 measurements)
Interventions	NUMBER OF STUDY CENTRES: NR COUNTRY/ LOCATION: Netherlands SETTING: NR TREATMENT BEFORE STUDY: 4 weeks' very‐low energy‐diet
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 Research, a peer‐reviewed journal, and was commercially funded by Novartis Consumer Health, Nyon, Switzerland
Stated aim of study	Quote from study: "therefore, we executed a follow‐up study on body weight maintenance with the aim of investigating whether the same green tea‐caffeine mixture may improve weight maintenance by preventing or limiting weight regain after weight loss of 5% to 10% in moderately obese subjects with a low or high habitual caffeine intake"
Notes	BMI: body mass index; NR: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote from study: participants "were divided into two stratified groups according to sex, BMI, age, dietary restraint, resting energy expenditure (REE), and being either habitual low caffeine consumers or habitual high caffeine consumers.... Subsequently, within the low or high habitual caffeine consumption groups, subjects were further stratified according to the characteristics mentioned above and randomised to a prospective green tea‐caffeine mixture treatment group and a placebo group for the weight maintenance phase" "Within the low or high caffeine intake group, subjects were stratified according to sex, BMI, age, dietary restraint, and REE and 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: "a randomised placebo‐controlled double blind parallel trial in 76 overweight and moderately obese subjects, matched for sex, age, BMI, height, body mass, and habitual caffeine intake was conducted" Quote from study: "a double‐blind administration of the supplementation (green tea‐caffeine mixture or placebo) was carried out" Comment: no mention of effectiveness of blinding efforts. Intervention and placebo delivered as a capsule, capsules not described for appearance
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: all outcomes that study reported on 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: there appears to have been no attrition of participants requiring explanation, or other incomplete outcome data
Selective reporting (reporting bias)	Low risk	Comment: outcomes specified at the beginning were adequately investigated and reported
Other bias	Unclear risk	Comment: study funded by Novartis, maker of test product. Results were positive so we judged that there was an unclear risk of bias