Table 4 Pooled effect sizes of overall studies and by health categories from fixed, random, and mixed effect models and heterogeneity statistics

Adiposity

Cheng, 2016 [35]

2.45

(1.56, 3.84)

7.7

14.6

Lin, 2018 [36]

1.59

(1.15, 2.18)

15.4

15.7

Wu, 2019 [37]

1.08

(0.88, 1.33)

35.5

16.5

Wu, 2018 [38]

1.07

(0.79, 1.44)

17.4

15.9

Lin, 2019 [39]

5.68

(3.85, 8.37)

10.4

15.2

Song Q, 2019 [40]

1.71

(0.44, 6.63)

0.9

6.6

Huang, 2013 [41]

1.57

(1.11, 2.23)

12.7

15.5

Fixed effect

1.53

(1.35, 1.73)

64.28

6

< 0.001

90.7

Random effect

1.81

(1.16, 2.83)

Cardio-metabolic risks

Wang M, 2019 [42]

1.45

(0.63, 3.33)

5.7

5.7

Li, 2017 [43]

1.36

(1.06, 1.74)

64.4

64.4

Wang, 2016 [44]

1.64

(1.14, 2.36)

29.9

29.9

Fixed effect

1.44

(1.18, 1.76)

0.71

2

0.701

0.0

Random effect

1.44

(1.18, 1.76)

Emotional problems

Qian, 2012 [45]

1.52

(1.31, 1.76)

35.0

35.0

Wang J, 2019 [46]

1.43

(1.03, 1.99)

6.9

6.9

Song Y, 2019 [47]

1.39

(1.16, 1.67)

23.0

23.0

Cao, 2011 [48]

1.52

(1.31, 1.76)

35.0

35.0

Fixed effect

1.48

(1.36, 1.62)

0.74

3

0.863

0.0

Random effect

1.48

(1.36, 1.62)

Myopia

Hu, 2020 [49]

1.46

(1.33, 1.60)

92.9

58.9

Pang, 2009 [50]

2.14

(1.54, 2.98)

7.1

41.1

Fixed effect

1.50

(1.37, 1.64)

4.83

1

0.028

79.3

Random effect

1.71

(1.18, 2.47)

Poor physical fitness

Huang, 2016 [51]

1.48

(1.13, 1.95)

0.5

2.2

Zhang, 2013 [52]

1.23

(1.18, 1.27)

24.7

25.4

Tian, 2017, aged 11–12 [53]

1.13

(1.06, 1.20)

9.4

18.9

Tian, 2017, aged 13–15 [53]

1.24

(1.20, 1.28)

34.9

27.1

Tian, 2017, aged 16–18 [53]

1.16

(1.12, 1.20)

30.5

26.5

Fixed effect

1.20

(1.18, 1.23)

14.76

4

0.005

72.9

Random effect

1.20

(1.15, 1.25)

Overall

Fixed effect

1.23

(1.21, 1.25)

141.59

20

< 0.001

85.9

Random effect

1.40

(1.31, 1.50)

Mixed effect

1.26

(1.21, 1.31)

25.75

4

< 0.001