Table 1

Baseline characteristics of the study subjects stratified by body composition

	N	Normal fat		P	High fat		P
	N	Normal FFM	High FFM	P	Normal FFM	High FFM	P
Sex
Boys	2844	2169 (50.61)	179 (51.73)	0.687	269 (61.14)	227 (47.00)	<0.001
Girls	2711	2117 (49.39)	167 (48.27)	0.687	171 (38.86)	256 (53.00)	<0.001
Demography/anthropometry
Age (years)	5555	10.56±3.07	10.45±3.03	0.541	10.44±2.99	10.79±2.97	0.077
Height (cm)	5555	146.92±17.49	151.37±17.66	<0.001	148.75±15.80	154.02±15.29	<0.001
Weight (kg)	5555	41.05±15.38	55.35±20.22	<0.001	58.68±19.49	71.78±22.27	<0.001
BMI (kg/m²)	5555	18.29±3.32	23.12±3.76	<0.001	25.72±3.64	29.42±4.17	<0.001
Cardiometabolic indicators
SBP (mm Hg)	5546	107.83±10.92	115.82±11.88	<0.001	117.09±11.44	121.50±10.88	<0.001
DBP (mm Hg)	5546	59.94±7.29	61.71±7.48	<0.001	64.64±7.82	65.66±7.66	0.046
TC (mmol/L)	5405	4.12±0.70	4.11±0.79	0.706	4.30±0.72	4.26±0.69	0.395
HDL-C (mmol/L)	5400	1.53±0.34	1.39±0.33	<0.001	1.31±0.29	1.23±0.27	<0.001
LDL-C (mmol/L)	5405	2.50±0.68	2.63±0.78	0.001	2.92±0.76	2.92±0.72	0.992
TG (mmol/L)	5401	0.83±0.37	0.94±0.50	<0.001	1.14±0.54	1.32±0.59	<0.001
FPG (mmol/L)	5401	4.92±0.52	4.91±0.40	0.665	4.98±0.61	5.00±0.87	0.607
Body composition indicators
FMP (%)	5555	20.87±8.31	24.98±7.33	<0.001	39.39±4.52	39.30±4.67	0.767
FMI (kg/m²)	5555	4.02±2.16	5.94±2.28	<0.001	10.18±2.09	11.65±2.59	<0.001
MMI (kg/m²)	5555	13.43±1.73	16.19±2.20	<0.001	14.62±2.01	16.74±2.18	<0.001
FFMI (kg/m²)	5555	14.27±1.83	17.18±2.34	<0.001	15.54±2.14	17.79±2.33	<0.001
Arm fat mass (kg)	5555	0.66±0.41	0.99±0.53	<0.001	1.83±0.84	2.35±1.13	<0.001
Leg fat mass (kg)	5555	1.63±0.86	2.32±0.98	<0.001	3.65±1.14	4.25±1.26	<0.001
Trunk fat mass (kg)	5555	3.75±3.31	6.81±4.11	<0.001	11.24±4.24	13.95±4.79	<0.001
Visceral fat region (m²)	5555	40.56±26.99	59.13±33.15	<0.001	119.01±42.32	135.91±45.45	<0.001
Fat mass (kg)	5555	9.17±5.94	14.39±7.23	<0.001	23.29±8.24	28.38±9.62	<0.001
Muscle mass (kg)	5555	30.00±10.41	38.54±13.55	<0.001	33.45±11.13	40.93±12.91	<0.001

Continuous variables shown as mean±SD.
P values were from tests comparing two groups by independent t-tests or χ2 tests. Those highlighted in bold indicate statistical significance (bilateral p<0.05).
BMI, body mass index; DBP, diastolic blood pressure; FFM, fat-free mass; FFMI, fat-free mass index; FMI, fat mass index; FMP, fat mass percentage; FPG, fasting plasma glucose; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; MMI, muscle mass index; SBP, systolic blood pressure; TC, total cholesterol; TG, triglycerides.