Lazaar 2007.

Study characteristics
Methods	Study design: cluster‐RCT Intervention period: 6 months Follow‐up period (post‐intervention): nil Differences in baseline characteristics: reported Reliable outcomes: reported Protection against contamination: NR Unit of allocation: school Unit of analysis: individual
Participants	N (obese: controls baseline) = 41 N (obese: controls follow‐up) = NR* N (non‐obese: controls baseline) = 187 N (non‐obese: controls follow‐up) = NR* N (obese: interventions baseline) = 59 N (obese: interventions follow‐up) = NR* N (non‐obese: interventions baseline) = 138 N (non‐obese: interventions follow‐up) = NR* *Data at 6 months collected from 98.9% of study participants overall. Numbers were NR by group. Setting (and number by study group): school (intervention N = 14; control N = 5) Intervention and control groups were further divided into obese (BMI > 97 th percentile) and non‐obese children to give a total of 4 trial groups (2 x intervention and 2 x control) Recruitment: children from participating local state schools were eligible if they were in their 1st or 2nd grade of elementary school, participating in the scheduled school PE classes, participating in < 3 h of extra‐school sports activity/week, free of any known disease and not participating in other studies. Geographic region: France Percentage of eligible population enrolled: NR Mean age: 7.4 ± 0.8 years (NR by group) Sex: 50% female (NR by group)
Interventions	Control: all children took part in scheduled school PE classes: Two 1‐h sessions each week held within the school timetable Aimed at providing children with a rational basis for their activity programmes and for exercise in general Various combinations of 5‐min exercises: exercises on co‐ordination, exercises devoted to posture and balance, relaxation techniques, rhythm and music, exercises devoted to creative movement, games relating to group participation etc. Activities increased in intensity and duration throughout the study Intervention: children in the intervention group were required to follow an additional PA programme: Two 1‐h sessions each week held after class Objective: a playful physical practice and 45 min of dynamic exercise within the hour Exercise programme designed to enhance the joy of movement, body awareness and team spirit Based on traditional games aimed at minimising children's inactivity During a session, 2 children were randomly selected to monitor their energy expenditure and estimate the average intensity of the sessions and quantify the total duration of PA PA interventions vs control
Outcomes	Primary: obesity status Secondary: BMI zBMI waist circumference skinfold thickness fat‐free mass Process evaluation: reported
Implementation‐related factors	Theoretical basis: NR Resources for intervention implementation (e.g. funding needed or staff hours required): NR Who delivered the intervention: reported PROGRESS categories assessed at baseline: reported (gender) PROGRESS categories analysed at outcome: reported (gender) Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: NR Economic evaluation: NR
Notes	Funding: this study was supported by grants from French National Plan for Nutrition and health (PNNS), the Comité Régional Exécutif des Actions de Santé d’Auvergne (CREAS),the Caisse Régionale d’Assurance Maladie d’Auvergne (CRAMA), the Appert Institutes, the town of Clermont‐Ferrand and schools’ governing bodies of Clermont‐Ferrand
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A draw was carried out to choose intervention schools
Allocation concealment (selection bias)	Low risk	All eligible children from within schools were automatically assigned to groups based according to school assignment and based on their individual BMI
Blinding (performance bias and detection bias) All outcomes	Unclear risk	NR
Incomplete outcome data (attrition bias) All outcomes	High risk	Only report total (N = 425), and group numbers (138; 59; 187; 41) once in text, so unclear if these were analysed or randomised numbers. supplementary data in tables also have no numbers.
Selective reporting (reporting bias)	Unclear risk	No protocol available; no tables visible ‐ link does not work; text indicates that post hoc analyses were conducted but these are not listed in the methods. Outcomes for zBMI are presented only for post hoc subgroup analyses (gender, baseline obesity). Main group differences are not presented
Other bias	Low risk	No additional threats to validity
Other bias‐ timing of recruitment of clusters	Unclear risk	NR: no consort figure in the paper or refereed to as supplementary file