Table 3

ORs (95% CI) for ≥2.3 kg increase in body weight over any 11-year period by physical activity levels

 N*Physical activity categoriesp Value†p Value‡
InactiveBelow recommendedRecommendedAbove recommended
Men
 Model 18344Ref.1.09 (0.99 to 1.19)1.06 (0.97 to 1.17)0.81 (0.71 to 0.92)0.07
 Model 28334Ref.1.02 (0.92 to 1.13)0.98 (0.88 to 1.09)0.79 (0.69 to 0.91)0.01
 Model 38230Ref.1.00 (0.90 to 1.11)0.97 (0.87 to 1.08)0.79 (0.69 to 0.91)<0.01
Stratified analyses§
 Age, years
  <405042Ref.1.04 (0.89 to 1.20)0.92 (0.79 to 1.08)0.89 (0.72 to 1.09)0.180.002
  40–593096Ref.0.99 (0.87 to 1.13)0.97 (0.85 to 1.11)0.77 (0.64 to 0.92)0.03
  ≥ 60206Ref.0.98 (0.72 to 1.33)0.96 (0.71 to 1.31)0.41 (0.28 to 0.62)<0.01
Occupational activity
 Inactive1290Ref.0.87 (0.69 to 1.10)0.87 (0.69 to 1.10)0.64 (0.47 to 0.87)0.010.83
 Walk and life5976Ref.0.98 (0.86 to 1.12)0.92 (0.80 to 1.06)0.72 (0.59 to 0.89)<0.01
 Heavy719Ref.1.17 (0.86 to 1.59)0.91 (0.66 to 1.26)0.77 (0.53 to 1.11)0.16
Smoking status
 Never3 225Ref.0.98 (0.83 to 1.15)0.88 (0.75 to 1.04)0.77 (0.63 to 0.95)0.010.74
 Former2 293Ref.1.01 (0.85 to 1.20)0.99 (0.83 to 1.19)0.72 (0.57. 0.92)0.05
 Current2 289Ref.1.05 (0.87 to 1.27)1.02 (0.82 to 1.26)0.75 (0.55 to 1.02)0.32
BMI categories, kg/m2
 <18.532Ref.0.66 (0.11 to 4.04)1.31 (0.19 to 9.26)0.97 (0.05 to 18.8)0.930.27
 18.5–24.94779Ref.0.92 (0.79 to 1.06)0.96 (0.82 to 1.12)0.78 (0.64 to 0.95)0.05
 25.0–29.93173Ref.1.07 (0.93 to 1.23)1.01 (0.87 to 1.16)0.81 (0.67 to 0.98)0.12
 ≥30.0360Ref.1.13 (0.83 to 1.53)0.96 (0.69 to 1.33)0.54 (0.34 to 0.86)0.06
Women
 Model 110 783Ref.1.34 (1.24 to 1.44)1.54 (1.42 to 1.67)1.18 (1.04 to 1.36)<0.001
 Model 210 744Ref.1.04 (0.96 to 1.13)1.03 (0.93 to 1.13)0.70 (0.60 to 0.81)0.02
 Model 310 413Ref.1.01 (0.92 to 1.10)0.97 (0.88 to 1.07)0.69 (0.59 to 0.82)0.006
Stratified analyses§
Age, years
 <406245Ref.0.97 (0.86 to 1.10)0.86 (0.74 to 0.99)0.81 (0.62 to 1.07)0.020.03
 40–594163Ref.1.03 (0.92 to 1.16)1.02 (0.90 to 1.15)0.60 (0.49 to 0.73)<0.01
 ≥ 60375Ref.0.98 (0.78 to 1.23)0.73 (0.57 to 0.94)0.31 (0.21 to 0.44)<0.001
Occupational activity
 Inactive1211Ref.0.93 (0.73 to 1.18)0.89 (0.69 to 1.14)0.48 (0.32 to 0.72)0.010.76
 Walk and life8176Ref.1.02 (0.92 to 1.14)0.97 (0.86 to 1.09)0.70 (0.57 to 0.85)0.02
 Heavy825Ref.0.72 (0.45 to 1.14)0.84 (0.47 to 1.49)0.68 (0.30 to 1.54)0.27
Smoking status
 Never4423Ref.1.04 (0.91 to 1.18)1.01 (0.87 to 1.16)0.68 (0.54 to 0.85)0.050.68
 Former2235Ref.0.99 (0.83 to 1.18)0.84 (0.70 to 1.01)0.55 (0.41 to 0.72)<0.001
 Current3357Ref.1.02 (0.88 to 1.18)1.11 (0.94 to 1.32)0.60 (0.44 to 0.82)0.42
BMI categories, kg/m2
 <18.5245Ref.0.49 (0.22 to 1.06)1.24 (0.41 to 3.73)0.83 (0.11 to 6.49)0.69<0.001
 18.5–24.97365Ref.0.91 (0.81 to 1.01)0.91 (0.81 to 1.03)0.73 (0.60 to 0.88)0.005
 25.0–29.92493Ref.1.14 (1.00 to 1.31)1.17 (1.00 to 1.36)0.77 (0.60 to 0.98)0.86
 ≥30.0680Ref.1.09 (0.87 to 1.37)1.17 (0.90 to 1.52)0.64 (0.40 to 1.03)0.97
  • Abbreviations: BMI, body mass index, calculated as body weight in kilograms divided by height in meters squared.

  • Model 1, adjusted for age; model 2 also for diabetes status (yes or no), smoking (never, former or current), and alcohol (abstainers, <1 time/14 days, 1–4 times/14 days or ≥5 times/14 days) and time period-dummies of HUNT wave (H1, H2 or H3) and model 3 additionally for occupational physical activity (sedentary, walk and life or heavy manual work).

  • *Number of participants at baseline (HUNT-1).

  • †p Value for trend across categories.

  • ‡p Value for interaction.

  • §Analytical model 2 is used in all stratified analyses.

  • BMI, body mass index; HUNT, Nord-Trøndelag County Health Study.