Association of daily sitting time and leisure-time physical activity with body fat among U.S. adults

Abstract

Background: Prolonged sitting and reduced physical activity lead to low energy expenditures. However, little is known about the joint impact of daily sitting time and physical activity on body fat distribution. We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.

Methods: This was a cross-sectional analysis of U.S. nationally representative data from the National Health and Nutrition Examination Survey 2011-2018 among adults aged 20 years or older. Daily sitting time and leisure-time physical activity (LTPA) were self-reported using the Global Physical Activity Questionnaire. Body fat (total and trunk fat percentage) was determined via dual X-ray absorptiometry.

Results: Among 10,808 adults, about 54.6% spent 6 h/day or more sitting; more than one-half reported no LTPA (inactive) or less than 150 min/week LTPA (insufficiently active) with only 43.3% reported 150 min/week or more LTPA (active) in the past week. After fully adjusting for sociodemographic data, lifestyle behaviors, and chronic conditions, prolonged sitting time and low levels of LTPA were associated with higher total and trunk fat percentages in both sexes. When stratifying by LTPA, the association between daily sitting time and body fat appeared to be stronger in those who were inactive/insufficiently active. In the joint analyses, inactive/insufficiently active adults who reported sitting more than 8 h/day had the highest total (female: 3.99% (95% confidence interval (95%CI): 3.09%-4.88%); male: 3.79% (95%CI: 2.75%-4.82%)) and trunk body fat percentages (female: 4.21% (95%CI: 3.09%-5.32%); male: 4.07% (95%CI: 2.95%-5.19%)) when compared with those who were active and sitting less than 4 h/day.

Conclusion: Prolonged daily sitting time was associated with increased body fat among U.S. adults. The higher body fat associated with 6 h/day sitting may not be offset by achieving recommended levels of physical activity.

Keywords: Adults; Body fat distribution; Physical activity; Sitting time.

Graphical abstract

Fig. 1

Joint association of daily sitting time and leisure-time physical activity with total body fat percentage among U.S. adults by sex, NHANES 2011–2018. Joint association of daily sitting time (h/day) and leisure-time physical activity (min/week) with total fat percentage within each subgroup: (A) male and (B) female. Estimates were adjusted for age (year), sex (male or female), race (non-Hispanic White, non-Hispanic Black, Hispanic, or other), educational attainment (less than high school, high school graduate, or above high school), family poverty ratio (<1.3, 1.3 to <3.5, or ≥3.5), smoking status (never, former, or current), alcohol use (never, former, or current), total energy intake and Healthy Eating Index-2015, hypertension (yes or no), hypercholesterolemia (yes or no), history of diabetes (yes or no), history of CVD (yes or no), history of cancer (yes or no), and depression (yes or no). 95%CI = 95% confidence interval; CVD = cardiovascular disease; NHANES = National Health and Nutrition Examination Survey.

Fig. 2

Joint association of daily sitting time and leisure-time physical activity with trunk body fat percentage among U.S. adults by sex, NHANES 2011–2018. Joint association of daily sitting time (h/day) and leisure-time physical activity (min/week) with trunk fat percentage within each subgroup: (A) male and (B) female. Estimates were adjusted for age (year), sex (male or female), race (non-Hispanic White, non-Hispanic Black, Hispanic, or other), educational attainment (less than high school, high school graduate, or above high school), family poverty ratio (<1.3, 1.3 to <3.5, or ≥3.5), smoking status (never, former, or current), alcohol use (never, former, or current), total energy intake and Healthy Eating Index-2015, hypertension (yes or no), hypercholesterolemia (yes or no), history of diabetes (yes or no), history of CVD (yes or no), history of cancer (yes or no), and depression (yes or no). 95%CI = 95% confidence interval; CVD = cardiovascular disease; NHANES = National Health and Nutrition Examination Survey.