Table 1. Characteristics of participants by sex (values are mean and SD unless otherwise stated).

	Boys N = 314	Girls N = 347	P-values for differences between sexes
Age (years)	14.39 (1.28)	13.97 (1.27)	≤ 0.0001
Body weight (kg)	55.21 (10.39)	53.77 (11.33)	0.12
Height (cm)	167.14 (9.43)	166.27 (9.81)	0.29
BMI*	19.53 (2.86)	19.38 (2.57)	0.09
Normal weight/overweight/obese (percent)a	91.7% / 7.1% / 1.2%	89.8% / 8.8% / 1.4%	0.668
Waist circumference (cm)*	72.49 (7.65)	71.11 (7.83)	0.03
HOMA-IR*	2.03 (1.32)	2.06 (1.56)	0.90
Systolic BP (mmHg)	107.99 (8.66)	107.07 (8.59)	0.21
Triglycerides (mmol/L)*	0.77 (0.30)	0.76 (0.37)	0.53
HDL-cholesterol (mmol/L)	1.42 (0.34)	1.48 (0.37)	0.08
METs cluster score*	0.02 (0.46)	-0.04 (0.51)	0.12
Parental educationb (percent reporting in each category)			0.94
High school education or less	8.7	7.2
Vocational education	29.6	29.9
Short tertiary education	9.9	13.3
Bachelor or equivalent	44.7	42.8
Master degree or higher education	7.1	6.8
Tanner stagesc
1–2, 3, 4, 5 (percent)	5.5/33.7/48.7/12.1	9.8/34.0/43.5/12.6	0.23
Flanker task
Reaction Time (ms)
Congruent	446.1 (55.5)	453.6 (55.7)	0.11
Incongruent	537.0 (76.8)	550.0 (74.9)	0.04
Response Accuracy (%)
Congruent*	95.4 (7.4)	95.8 (5.7)	0.37
Incongruent*	81.0 (14.0)	82.2 (12.7)	0.30
Interference score
Reaction time (ms)	90.9 (43.1)	96.4 (40.4)	0.12
Accuracy (%)	14.3 (10.7)	13.7 (10.2	0.45

^a BMI categories according to International Obesity Task Force age- and sex specific cutoff points [30].

^b Maternal or female guardians highest completed education was used as the parental education indicator if available.

^c Category 1 and 2 are collapsed, as there were few participants in these categories.

*Not normally distributed data, transformed using the natural logarithm for analyses.