Table 1 Descriptive statistics of secondary schools separately for (a subsample of) certified- and non-certified schools

Schools (N)

85

171

67

Students (N)

65,731

102,396

58,663

Fruit consumption (days per week)³ (Mean (SD))

4.34 (2.41)

4.30 (2.42)*

4.34 (2.40)

Vegetable consumption (days per week)³ (Mean (SD))

5.71 (1.54)

5.67 (1.57)*

5.71 (1.54)

School health promotion

Number of years Healthy School (Mean (SD))

1.42 (1.86)

-*

1.40 (1.85)

Healthy School topic certificates (yes) (%)⁵

Nutrition

18.60

-*

20.11

Physical activity

20.93

-*

22.28

Well-being

6.98

-*

7.07

Smoking, alcohol, and drug prevention

6.98

-*

8.15

General school characteristics

School size (number of students) (Mean (SD))

952 (575)

859 (506)

971 (560)

Urbanicity school area (%)

 High

48.84

40.17*

50.54

 Medium

15.81

25.21*

14.13

 Low

35.35

34.63

35.33

School type (%)

 Public

22.79

25.21

22.28

 Independent non-denominational

11.63

12.47

12.50

 Catholic

28.84

30.75

30.43

 Protestant

20.93

15.79

20.65

 Rest

15.81

15.79

14.13

School population characteristics (Mean (SD))

Poverty level (proportion)

0.08 (0.12)

0.08 (0.12)

0.09 (0.12)

Proportion high educational attainment⁷;

0.52 (0.20)

0.51 (0.19)

0.53 (0.20)

Household income^{6 7}

 Proportion low household income

0.03 (0.02)

0.03 (0.02)

0.03 (0.02)

 Proportion high household income

0.57 (0.14)

0.57 (0.14)

0.58 (0.14)

Migration background^{6 7}

 Proportion first generation

0.03 (0.02)

0.03 (0.03)

0.03 (0.02)

 Proportion second generation

0.13 (0.08)

0.13 (0.08)

0.13 (0.08)

Age⁶

 Proportion younger than 14

0.38 (0.13)

0.36 (0.17)

0.38 (0.13)

 Proportion 14–15 years

0.45 (0.09)

0.45 (0.10)

0.45 (0.08)

Grade⁶

 Proportion grade 2

0.55 (0.18)

0.52 (0.23)

0.55 (0.17)

Educational track⁶

 Proportion pre-university education

0.20 (0.26)

0.19 (0.26)

0.21 (0.26)

 Proportion senior general secondary education

0.24 (0.24)

0.23 (0.25)

0.25 (0.24)

Proportion good self-rated general health

0.86 (0.05)

0.85 (0.05)

0.86 (0.04)

Proportion borderline/abnormal psychosocial health

0.26 (0.07)

0.27 (0.08)

0.26 (0.07)

Proportion bullied at school (yes)¹⁰

0.11 (0.05)

0.11 (0.05)

0.11 (0.04)

Proportion cyberbullied (yes)⁹

0.06 (0.03)

0.06 (0.03)

0.06 (0.03)

Proportion truancy (yes)⁸

0.09 (0.05)

0.10 (0.06)*

0.09 (0.04)

Proportion sickness (more than five days)₈

0.04 (0.03)

0.04 (0.03)

0.04 (0.03)

School experience^{6 11}

 Proportion positive

0.54 (0.09)

0.52 (0.10)

0.54 (0.09)

 Proportion negative

0.10 (0.04)

0.10 (0.04)

0.09 (0.04)

Urbanicity home area^{6 12}

 Proportion high urbanicity

0.35 (0.28)

0.32 (0.30)

0.35 (0.28)

 Proportion low urbanicity

0.49 (0.31)

0.49 (0.33)

0.49 (0.31)