Frequency of working at home, body mass index, and productivity in Japanese office workers: A cohort study

Since the start of the COVID-19 pandemic, the number of people working at home has grown significantly.

This cohort study aimed to investigate whether the frequency of working at home was associated with changes in body mass index (BMI) and productivity from 2018 to 2020.

Frequency of working at home was self-reported. Participants were classified into three groups based on mean frequency of working at home per week (no working at home: ≦ 0.5 days, low frequency: 0.5 to 2.5 days, and high frequency: >2.5 days). Productivity was measured using a numerical rating scale, and BMI was calculated using height and weight. Changes in BMI and productivity were calculated by subtracting 2018 data from 2020 data. Linear regression analysis was performed by considering BMI and productivity change as outcomes and frequency of working at home as explanatory variable.

BMI change in the high frequency group was significantly smaller than in the group that did not work at home (crude; coefficient: -0.27; 95% CI: -0.55--0.01, adjusted; coefficient: -0.30; 95% CI: -0.60--0.01). Frequency of working at home was not associated with productivity change.

Working at home may be a solution for preventing BMI from increasing significantly.