Changes in Step-Defined Physical Activity by Occupation: The National Health and Nutrition Survey of Japan 2001-2019.

Background: Accumulating more steps/day provides considerable health benefits; however, studies of steps/day trends among a working population are quite limited. Moreover, steps/day trends may differ among occupations. We aimed to assess changes in steps/day by occupations in the Japanese working population.

Methods: Workers aged 20-65 years were identified from the Japanese National Health and Nutrition Examination Survey conducted between 2001 and 2019. Steps/day were assessed using a pedometer. Occupations with or without income were categorized as professionals, managers, and clerks; sales workers, service workers, protective service workers, and agricultural/forestry/fishery workers; transport/machine operators; manufacturing/construction/cleaning laborers; homemakers; and unemployed individuals. Steps/day per decade were compiled for 2001-2010 and 2011-2019, and differences in age-adjusted steps/day between 2001-2010 and 2011-2019 were evaluated by an analysis of covariance.

Results: A total of 105,492 workers among occupational categories were analyzed. Changes in age-adjusted steps/day (95% CI) per decade among occupations with income ranged from -873 (-1426 to -321) to 352 (-19 to 722) while those for homemakers and the unemployed ranged from -766 (-875 to -677) to -659 (-890 to -429). Only transport/machine operators did not reduce their steps/day (Δ = 352 [-19 to 722]); all other occupations significantly decreased their steps/day. Among occupations with income, the largest decrease was observed in protective service workers, followed by clerks. Moreover, clerks remained the occupational group with the lowest amount of steps/day in both periods.

Conclusions: Most included occupations reduced their steps/day, and the degree of change varied widely among occupations. Further promotion of steps/day is warranted, especially for clerks.