Table 2

Lifestyle across screen time levels during weekends for adolescents aged 15–18 years, The Tromsø Study, Fit Futures 1

Girls n=463Boys n=484
Screen time weekends (h)0–22–44–6>6p Value0–22–44–6>6p Value
Number of participants731541736349112184139
BMI (kg/m2)22.3 (4.0)22.3 (4.2)22.3 (3.4)23.2 (4.8)0.45122.9 (4.0)21.1 (3.0)22.6 (4.2)*23.0 (4.9)*0.002
Vitamin D level
(serum 25(OH) D nmol/L)
56.0 (20.7)58.5 (23.1)53.0 (24.2)47.8 (21.6)*0.02241.8 (20.7)42.9 (20.4)42.7 (20.1)35.0 (19.4)*†0.027
Physical activity (%)‡*‡*<0.001*‡*†<0.001
 Hard training24.722.113.33.2 18.436.627.27.9 
 Sports31.528.628.930.2 22.328.622.318.0 
 Moderate38.441.639.541.3 30.621.428.322.3 
 Sedentary5.57.818.525.4 28.613.422.351.8 
Calcium intake (%)0.1060.443
 Sufficient89.089.687.977.8 91.892.990.887.1 
 Low11.010.412.122.2 8.27.19.212.9 
Soft drinks sugar (%)‡*<0.001*0.004
 Rarely52.137.028.322.214.317.05.47.2
 1 glass a day46.661.065.357.167.367.079.366.9
 ≥2 glasses a day1.41.95.817.516.316.115.225.2
Soft drinks sweetener (%)0.0520.058
 Rarely69.947.449.154.0 73.567.053.359.0 
 1 glass a day26.650.046.841.3 24.529.542.433.8 
 ≥2 glasses a day2.72.62.93.22.02.73.86.5
Smoking (%)0.5550.382
 No, never76.783.880.369.875.571.481.574.1
 Sometimes17.813.616.822.218.425.016.323.0
 Daily5.52.62.94.86.13.62.22.9
Alcohol (%)0.6700.912
 Never21.924.022.027.032.733.033.730.2
 Up to once per month46.650.643.444.4 38.833.037.040.3 
 Twice or more/month31.525.334.728.6 26.533.929.328.8 
  • Statistically significant results at 5% level are displayed in bold. Data are means (SD) or %.

  • *2–4 h group.

  • †4–6 h group.

  • ‡0–2 h group.

  • BMI, body mass index.