Singh 2009.

Methods	Design: cluster randomized controlled trial Theoretical framework: Intervention Mapping Protocol Number of intervention groups: 1 Number of control groups: 1 Follow‐up: 1 year post‐intervention
Participants	N: 875 Age (mean): 12.7 years Sex: male and female Ethnicity: : White
Interventions	Country: Netherlands Setting: school, unstated whether urban or rural Provider: teachers although unclear Duration: 8 months Intervention: an interdisciplinary program with adapted curriculum including an individual component (11 lessons in biology and physical education) and environmental change component including encouragement for schools to increase physical education and provision of advice for schools related to cafeteria changes Control: regular curriculum
Outcomes	Body mass index (kg/m2) Television viewing (minutes spent engaged in inactivity)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: randomization process not reported
Allocation concealment (selection bias)	Low risk	Comment: criterion not applicable because all participants were allocated at 1 point in time following recruitment, so at time of recruitment allocation was not known
Blinding (performance bias and detection bias) All outcomes	High risk	Quote: "all measurements were performed within a 6‐week period according to a standardized protocol by a trained research team, which was not blinded to the group assignment" (Singh 2009, p310)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "all analyses were performed according to the intention‐to‐treat principle" (Singh 2009, p311)
Selective reporting (reporting bias)	Low risk	Comment: all outcomes identified a priori were reported on
Confounders controlled?	Low risk	Comment: all relevant confounders were accounted for
Data collection methods valid and reliable?	Low risk	Comment: more detail on reliability and validity could be given