Table 3

BMI change by occupational physical activity change for the overall cohort and in strata of sex, birth year, smoking, education and leisure-time physical activity change. The Tromsø Study 1974-2016.

Tromsø 1–7Change occupational physical activity examinations 1 and 2
(1974–2016)TotalPersistently InactivePersistently ActiveActive to InactiveInactive to ActivePequality
BMI change examinations 2 and 3
Total (N) 11 308 3692 5560 741 1315
 BMI (kg/m2)Mean
95% CI
0.81
0.75 to 0.87
0.87
0.82 to 0.92
0.81
0.67 to 0.94
0.91
0.81 to 1.01
0.25
Sex
Women (n)548216382925319600
 BMI (kg/m2)Mean
95% CI
1.06
0.96 to 1.17
1.09
1.02 to 1.17
1.10
0.87 to 1.33
1.18
1.01 to 1.34
0.74
Men (n)582620542635422715
 BMI (kg/m2)Mean
95% CI
0.56
0.49 to 0.63
0.67
0.61 to 0.74
0.55
0.39 to 0.71
0.66
0.54 to 0.78
0.11
Birth year
≤1929 (n)7482393506099
 BMI (kg/m2)Mean
95% CI
0.09
0.31 to 0.14
0.15
−0.03 to 0.33
0.20
−0.22 to 0.62
0.31
0.64 to 0.01
0.054
1930–1939 (n)29748561580189349
 BMI (kg/m2)Mean
95% CI
0.43
0.30 to 0.57
0.53
0.43 to 0.62
0.55
0.28 to 0.82
0.36
0.16 to 0.56
0.39
1940–1949 (n)419214832020260429
 BMI (kg/m2)Mean
95% CI
0.85
0.75 to 0.95
0.92
0.84 to 1.00
0.73
0.50 to 0.96
1.06
0.88 to 1.24
0.10
1950–1959 (n)39479321430205380
 BMI (kg/m2)Mean
95% CI
1.34
1.22 to 1.45
1.28
1.19 to 1.37
1.28
1.04 to 1.52
1.52
1.34 to 1.70
0.12
≥1960 (n)4471821802758
 BMI (kg/m2)Mean
95% CI
1.04
0.69 to 1.39
1.11
0.75 to 1.46
1.13
0.24 to 2.02
1.34
0.72 to 1.95
0.88
Smoking
Current smoker (n)448012502343306581
 BMI (kg/m2)Mean
95% CI
0.96
0.85 to 1.07
1.00
0.92 to 1.08
0.82
0.60 to 1.03
1.02
0.86 to 1.17
0.44
Previous smoker (n)1790703782126179
 BMI (kg/m2)Mean
95% CI
0.34
0.19 to 0.48
0.42
0.28 to 0.55
0.52
0.19 to 0.85
0.43
0.16 to 0.71
0.71
Never smoker (n)503817392435309555
 BMI (kg/m2)Mean
95% CI
0.87
0.78 to 0.95
0.91
0.83 to 0.98
0.91
0.71 to 1.10
0.95
0.81 to 1.10
0.79
Education
Primary school (n)46988783010265545
 BMI (kg/m2)Mean
95% CI
0.75
0.62 to 0.88
0.83
0.76 to 0.90
0.68
0.45 to 0.92
0.79
0.63 to 0.95
0.52
High school (n)361013611566271412
 BMI (kg/m2)Mean
95% CI
0.87
0.77 to 0.97
0.95
0.86 to 1.04
0.82
0.60 to 1.03
1.11
0.93 to 1.29
0.09
University<4 years (n)1641787539117198
 BMI (kg/m2)Mean
95% CI
0.85
0.72 to 0.98
0.90
0.75 to 1.06
0.88
0.55 to 1.21
0.97
0.71 to 1.22
0.85
University>4 years (n)135966644588160
 BMI (kg/m2)Mean
95% CI
0.72
0.59 to 0.85
0.80
0.64 to 0.96
1.16
0.81 to 1.50
0.75
0.49 to 1.01
0.14
Leisure time physical activity change examinations 1 and 2*
Persistently Inactive (n)81333231763101
 BMI (kg/m2)Mean
95% CI
0.81
0.60 to 1.03
0.98
0.76 to 1.20
1.25
0.76 to 1.73
0.94
0.55 to 1.33
0.42
Persistently Active (n)536815992798328643
 BMI (kg/m2)Mean
95% CI
1.00
0.91 to 1.08
1.02
0.95 to 1.08
0.82
0.63 to 1.02
1.13
1.00 to 1.27
0.08
Active to Inactive (n)97429146971143
 BMI (kg/m2)Mean
95% CI
0.82
0.60 to 1.04
1.03
0.86 to 1.21
1.24
0.80 to 1.68
1.11
0.80 to 1.42
0.23
Inactive to Active (n)99934845166134
 BMI (kg/m2)Mean
95% CI
0.90
0.69 to 1.11
1.09
0.91 to 1.28
0.89
0.42 to 1.37
0.77
0.43 to 1.10
0.31
  • Data are adjusted for sex, birth year, smoking, education and BMI at examination 2, and are shown as adjusted mean and 95% CI. Examination 1 refers to the first survey of the three attended surveys; examination 2 refers to the second survey of the three attended surveys; examination 3 refers to the third survey of the three attended surveys. Pequality is the main difference between groups.

  • *The leisure-time Saltin-Grimby Physcial Activity Scale was not included in Tromsø 4 (1994–1995).

  • BMI, body mass index.