Table 1.

Characteristics of adolescents participating in the test–retest reliability and construct validity studies; DOiT (Dutch Obesity Intervention in Teenagers) questionnaire assessing energy balance-related behaviours. Data are presented as n and % except where indicated

	Test–retest reliability		Construct validity
	n or Mean	% or sd	n or Mean	% or sd
No. of participants in study, n	111	–	20	–
Age (years), mean and sd	13·3	0·5	13·2	0·8
Male gender	61	55	50	50
Ethnicity*
Western (both parents are Western)	85	77	16	80
Non-Western	26	23	4	20
Family status
Traditional (mother and father)	83	75	16	80
Non-traditional	28	25	4	20

*This classification is based on that of CBS Statistics Netherlands. Someone with a Western background is someone originating from a country in Europe (excl. Turkey), North America, Oceania, Indonesia or Japan. Someone with a non-Western background is someone originating from a country in Africa, South America, Asia (excl. Indonesia and Japan) or Turkey.