Last updated on 5-12-2024 by Laïla Boulbayem
Why do we study sedentary behaviour in adults?
- Sedentary behaviour refers to activities that require low energy expenditure, such as sitting, lying down, watching TV, or other screen-based activities.
- Increased sedentary behaviour is linked to negative health outcomes, including higher risks of all-cause mortality, cardiovascular disease mortality, cancer, and type 2 diabetes.
- Sedentary behaviour differs from physical inactivity; an individual can meet physical activity guidelines while still leading a sedentary lifestyle due to prolonged sitting, such as during desk work. Sedentary behaviour, however, also contributes to physical inactivity, which is a leading cause of 4–5 million preventable deaths annually worldwide.
- The WHO recommends that adults should limit the amount of time spent being sedentary. It is also advised to replace sedentary time with physical activity of any intensity, including light intensity (e.g., walking), as this provides health benefits.
- Studying sedentary behaviour is crucial from a public health perspective because excessive sedentary behaviour is widespread and contributes to chronic diseases and mental health issues, reducing quality of life. Addressing it can help prevent these conditions, reduce healthcare costs and improve overall population well-being.
How do we do it?
- Sedentary behaviour in adults was examined using the long version of the self-reported International Physical Activity Questionnaire (IPAQ). In addition to physical activity, this questionnaire is used to determine total sedentary time and includes therefore the following questions:
- ‘On how many days, in the last seven days, did you travel by a motor vehicle such as train, bus, car or tram? On such a day, how much total time on average did you spend travelling by car, bus, train or other motor vehicle?’
- ‘In the last seven days, how much time, on average, have you spent sitting on a week / weekend day?’ This question focuses on the time you spent sitting in the past seven days at work, home, during study, or in your leisure time, including sitting at a desk, reading, or watching TV. Time spent sitting in a motor vehicle is not included.
- To indicate high sedentary time, a threshold of eight hours per day was used.
- Although questionnaires have many advantages, they also have some downsides. People often struggle to accurately assess their own sedentary behaviour. This misjudgment, combined with forgetfulness and the desire to provide socially acceptable answers, can result in measurement errors.
Key results
Men spend more time per day being sedentary than women.
Both women and men are more sedentary on weekdays compared to weekend days.
The higher the educational level, the more time adults spent being sedentary.
The proportion of adults who report being sedentary for more than eight hours per day is higher in Flanders than in Wallonia.
Age and sex
Proportion of the adult Belgian population aged 18 to 64 years reporting being sedentary for more than eight hours per day on (A) week and (B) weekend days, by age and sex, Belgium: 2022-2023
A. On weekdays
B. On weekend days
- Crude = results weighted for season, age, sex, and socioeconomic status.
- In general, both women and men spend more time in sedentary behaviour on weekdays compared to weekend days.
- On weekdays, the proportion of young adult men (aged 18 – 39 years) who report being sedentary more than eight hours per day is higher (47%) compared to that of young adult women (36%). There is no sex difference for middle-aged adults (aged 40 – 64 years).
- On weekdays, the proportion of being sedentary more than eight hours per day is higher in young adults (aged 18 to 39 years; 42%) compared to middle-aged adults (aged 40 – 64 years; 32%).
- On weekend days, no difference is observed between women and men, nor between age groups.
Average minutes per day spent by the adult Belgian population aged 18 to 64 years while being sedentary (time in vehicle included) on (A) week and (B) weekend days, by age and sex, Belgium: 2022-2023
A. On week days
B. On weekend days
- Crude = results weighted for season, age, sex, and socioeconomic status.
- The average time spent being sedentary per day is higher on weekdays (406 minutes per day; 6 hours 46 minutes per day) than on weekend days (328 minutes per day; 5 hours 28 minutes per day).
- In general, men spent more time being sedentary than women.
- On weekdays, young adults (aged 18 to 39 years) spent an average of 430 minutes per day being sedentary (7 hours 10 minutes per day) which is higher than the average time spent being sedentary by middle-aged adults (aged 40 to 64 years), who report 390 minutes per day (6 hours 30 minutes per day).
- On weekend days, there is no difference between age groups.
Educational level
Proportion of the adult Belgian population aged 18 to 64 years reporting being sedentary for more than eight hours per day, on week and weekend days, by educational level, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- The educational level is calculated at the household level by considering the highest diploma obtained by: (i) the respondents or their partner for adults (aged 18 years and above), or (ii) the father and mother (or carer, if applicable) for children and adolescents (aged 3 to 17 years). However, for simplicity, we refer to the educational level of individuals rather than the educational level of their households.
- On weekdays, 26% of people with low-educational levels report being sedentary for more than eight hours per day, which is lower than for people with mid- (40%) and high- educational levels (51%).
- On weekend days, there is no difference in proportion of being sedentary for more than eight hours a day between people with low-educational levels (21%) and people with mid-educational levels (19%), but this proportion is higher in both groups compared to those with a high-educational level (12%).
Average minutes per day spent by the adult Belgian population aged 18 to 64 years while being sedentary (time in vehicle included) on week and weekend days, by educational level, Belgium: 2022-2023
- Crude = results weighted for season, age, sex, and socioeconomic status.
- The educational level is calculated at the household level by considering the highest diploma obtained by: (i) the respondents or their partner for adults (aged 18 years and above), or (ii) the father and mother (or carer, if applicable) for children and adolescents (aged 3 to 17 years). However, for simplicity, we refer to the educational level of individuals rather than the educational level of their households.
- On weekdays, the time spent being sedentary per day increases across educational level with 363 minutes/ day (6 hours 3 minutes/day) for people with low-educational levels, 418 minutes/day (=6 hours 58 minutes/day) for people with mid-educational levels and 482 minutes/day (=8 hours 2 minutes/day) for people with high-educational levels.
- On weekend days, there is no difference in time spent being sedentary per day according to educational levels.
Region and year
Proportion of the adult Belgian population aged 18 to 64 years reporting being sedentary for more than eight hours per day, on week and weekend days, by region, Belgium: 2022-2023
- Adjusted = results weighted for season, age, sex and socioeconomic status, and adjusted according to age and sex based on linear regression model (using the Belgian population of 2022-2023 as reference).
- Both on week and weekend days, the proportion of adults who report more than eight hours of sedentary time per day is higher in Flanders (40% on weekdays; 21% on weekend days) than in Wallonia (30% on weekdays; 14% on weekend days).
Average minutes per day spent by the adult Belgian population aged 18 to 64 years being sedentary (time in vehicle included) on week and weekend days, by region, Belgium: 2022-2023
- Adjusted = results weighted for season, age, sex and socioeconomic status, and adjusted according to age and sex based on linear regression model (using the Belgian population of 2022-2023 as reference).
- Adults spent more time being sedentary in Flanders compared to Wallonia, both on week and weekend days.
Proportion of the adult Belgian population aged 18 to 64 years reporting being sedentary for more than eight hours per day on (A) week and (B) weekend days, by region and year, Belgium: 2022-2023
A. On week days
B. On weekend days
- Adjusted = results weighted for season, age, sex and socioeconomic status, and adjusted according to age and sex based on linear regression model (using the Belgian population of 2022-2023 as reference).
- There has been no change over time in the proportion of adults reporting more than eight hours of sedentary time between 2014-2015 and 2022-2023.
Average minutes per day spent by the adult Belgian population aged 18 to 64 years while being sedentary (time in vehicle included) on (A) week and (B) weekend days, by region and year, Belgium: 2022-2023
A. On week days
B. On weekend days
- Adjusted = results weighted for season, age, sex and socioeconomic status, and adjusted according to age and sex based on linear regression model (using the Belgian population of 2022-2023 as reference).
- There was no change in the reported sedentary time per day from 2014-2015 to 2022-2023, both nationally across Belgium and regionally across Flanders and Wallonia.
Please cite this page as: Sciensano. Physical activity and sedentary behaviour in adults: Total sedentary behaviour and guidelines, Food Consumption Survey 2022-2023, December 2024, Brussels, Belgium, https://www.sciensano.be/en/results-national-food-consumption-survey-2022-2023/physical-activity-and-sedentary-behaviour-adults/total-sedentary-behaviour-and-guidelines-adults