Table 1.

Description of the children and adolescents at baseline

	Intervention group		Control group
	Children (n=375)	Adolescents (n=94)	Children (n=327)	Adolescents (n=98)
Age (mean±SD)	9.21 (0.56)	13.2 (0.58)	9.23 (0.59)	13.1 (0.61)
Gender
Boys, % (n)	54.7 (205)	47.4 (45)	47.7 (156)	40.6 (40)
Girls, % (n)	45.3 (170)	52.6 (49)	52.3 (171)	59.4 (58)
Ethnicity
West Europe, % (n)	55.2 (207)	85.1 (82)	73.7 (241)	80.4 (78)
East Mediterranean, % (n)	31.2 (117)	8.9 (6)	14.7 (48)	8.3 (9)
East-Central Europe, % (n)	2.9 (11)	2.0 (2)	4.0 (13)	4.1 (4)
American Regions, % (n)	8.3 (31)	3.0 (3)	6.4 (21)	6.2 (6)
African Regions, % (n)	1.3 (5)	1.0 (1)	0.3 (1)	0
South-West Asia, % (n)	0.3 (1)	0	0	1.0 (1)
West of Pacific, % (n)	0.8 (3)	0	0.9 (3)	0

Ethnicity was documented according to the WHO (WHO presence in countries, territories and areas, 2015).