Table 3 Main characteristics of systematic reviews (SRs).

Systematic review design

 Number of studies included

301 (total)

Ranged from 13⁵¹ to 172⁵⁴

 Participants (total number)

230,915

Spiga et al.⁵⁴ alone included 189,707 participants

 Range year of the study included

(2004–2023)

Based on search periods reported

 Place (country-geographic location)

Mostly high-income countries

UK, USA, Australia^50,52,54

 Only RCT

1/6

Spiga et al.⁵⁴

 RCT and non RCT

5/6

Allcott-Watson et al.⁴⁹, Casado-Robles et al.⁵⁰, Dai⁵¹, Klein et al.⁵² and Larouche et al.⁵³

 Number RCT

213/301

Most from Klein et al.⁵², Larouche et al.⁵³ and Spiga et al.⁵⁴

Target population

 Included children under 11 years

6/6

All reviews included this age group; some extended to adolescents up to 19 years

 Reported sex/gender differences

5/6

Allcott-Watson et al.⁴⁹, Casado-Robles et al.⁵⁰, Dai⁵¹, Klein et al.⁵² and Spiga et al.⁵⁴

Intervention type

 Physical activity promotion

3/6

Casado-Robles et al.⁵⁰, Dai⁵¹ and Larouche et al.⁵³

 Only healthy eating education

0/6

None reported

 Combined interventions (PA + nutrition)

3/6

Allcott-Watson et al.⁴⁹, Klein et al.⁵² and Spiga et al.⁵⁴

 Intervention settings

6/6

All reviews focused on schools or related settings (community/home)

 Structural/environmental changes

5/6

Allcott-Watson et al.⁴⁹, Casado-Robles et al.⁵⁰, Klein et al.⁵², Larouche et al.⁵³ and Spiga et al.⁵⁴

 Explicit theoretical framework

5/6

Social cognitive theory, self-determination theory, etc., though inconsistently applied

 BCT described via BCTTv1 or TDF

1/6

Allcott-Watson et al.⁴⁹

 Technology-delivered interventions

2/6

Casado-Robles et al.⁵⁰ and Spiga et al.⁵⁴

Behavioral outcomes

 Increased physical activity

6/6

All reviews reported improvements (e.g., MVPA, steps, active transport)

 Improved dietary habits

5/6

Allcott-Watson et al.⁴⁹, Casado-Robles et al.⁵⁰, Dai⁵¹, Klein et al.⁵² and Spiga et al.⁵⁴

 Adherence to healthy behaviors

5/6

Reported inconsistently

Cognitive outcomes

 Improved self-efficacy

3/6

Allcott-Watson et al.⁴⁹, Dai⁵¹ and Klein et al.⁵²

 Increased knowledge

3/6

Dai⁵¹, Klein et al.⁵² and Spiga et al.⁵⁴

 Positive attitudes toward healthy behaviors

3/6

Reported qualitatively; not always with validated scales

Biological outcomes

 BMI or zBMI reduction

6/6

Most consistent indicator; strongest in Spiga et al.⁵⁴

 Waist circumference, body composition, fitness

4/6

Dai⁵¹, Klein et al.⁵², Larouche et al.⁵³ and Spiga et al.⁵⁴

 Other biomarkers (cholesterol, glucose)

2/6

Klein et al.⁵² and Spiga et al.⁵⁴

Meta-analysis and certainty of evidence

 Meta-analysis

2/6

Casado-Robles et al.⁵⁰ and Spiga et al.⁵⁴

 Certainty of evidence (GRADE)

2/6

Reported in Casado-Robles et al.⁵⁰ and Spiga et al.⁵⁴