Table 1: Baseline descriptive characteristics of the study population stratified by sex (n=785)

From: Fatness predicts decreased physical activity and increased sedentary time, but not vice versa: support from a longitudinal study in 8- to 11-year-old children

VariablenBoys (n=407)Girls (n=378)P-value
 Age (years)78510.0±0.69.9±0.70.001
 3rd grade/4th grade (%)78547/5349/510.89
 Pubertal status (% 1/2/3)78576.9/19.4/3.753.4/36.2/10.3<0.001
 Parents born in Denmark (% 0/1/2)7858.6/12.5/78.99.0/11.6/79.40.92
 Highest education of household (%)a7834.7/34.0/38.7/22.76.1/35.3/39.3/19.40.60
 Weight (kg)78535.3±7.234.7±6.90.18
 Height (cm)785142.7±7.1142.0±7.10.21
 Body mass index Z-scoreb7850.19±1.110.06±1.040.07
 Weight status (% uw/nw/ow/ob)c7858.9/77.9/11.1/2.211.9/74.6/11.9/1.60.46
 Fat mass index7853.1 (2.2;4.8)4.1 (2.9;5.7)<0.001d
 Fat-free mass index78512.8 (12.2;13.4)11.8 (11.2;12.4)<0.001d
 Body fat (%)78518.8 (13.8;26.4)24.8 (18.9;31.2)<0.001d
Movement behaviors
 Physical activity (cpm)e757521±139455±116<0.001
 Sedentary time (%)f75752.5±7.052.3±6.40.70
 Screen time (hh:mm day–1)7622:34 (1:51;3:28)2:15 (1:34;3:02)<0.001d
 MVPA (min day–1)75757±2438±16<0.001
 Sleep duration (hh:mm per night)7379:13±0:279:15±0:280.26
 CSHQ78042 (39;46)42 (39;46)0.17d
 Energy intake (kJ)7698101±17377013±1447<0.001
 Energy density (kJ g–1)7697.8±1.27.4±1.1<0.001
  1. Abbreviations: CSHQ, Children’s Sleep Habits Questionnaire; MVPA, moderate-to-vigorous physical activity;uw/nw/ow/ob, underweight/normal weight/overweight non-obese/obese.
  2. Data are presented as mean±s.d., median (interquartile range) or proportions. Sex differences were tested using a two-sample t-test or Pearson’s χ2 test.
  3. aHighest education of household: 10/11–12/13–16/17 years.
  4. bBased on World Health Organization Growth Reference data from 2007.14
  5. cBased on age- and sex-specific cutoffs defined to pass through body mass index of 18.5, 25 and 30 kg m–2 at 18 years of age.15, 16.
  6. dUsing log-transformed P-values.
  7. eTotal tri-axial physical activity (cpm): boys, 1055±234; girls, 933±193 (P<0.001).
  8. fSedentary time (hh:mm day–1): boys, 7:55±1:07; girls, 7:50±1:00 (P=0.23).