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Updated: Mar 22, 2026
Assessment of Child Anthropometry in a Large Epidemiologic Study
Published on: February 2, 2017
Objectively measured physical activity and sedentary time: cross-sectional and prospective associations with
Lucy J Griffiths1, Francesco Sera1, Mario Cortina-Borja2
1Life Course Epidemiology and Biostatistics, UCL Institute of Child Health, London, UK.
Insights
Increased physical activity (PA) in 7-year-olds is linked to lower adiposity at ages 7 and 11. These benefits were more pronounced in Black and South Asian children, highlighting the importance of early activity for long-term health.
Area of Science:
- Pediatric obesity research
- Public health and preventive medicine
- Childhood physical activity and sedentary behavior
Background:
- Childhood obesity is a growing public health concern.
- Understanding the long-term impact of physical activity and sedentary time is crucial for developing effective interventions.
Purpose of the Study:
- To investigate the association between physical activity (PA) and sedentary time (ST) in primary school children and their adiposity levels.
- To determine if these associations differ based on sex or ethnic group.
Main Methods:
- A nationally representative prospective cohort study involving 6497 children born in the UK (2000-2002).
- Adiposity measures (BMI, FMI, FFMI) were assessed at ages 7 and 11 years.
- Physical activity (total PA, MVPA) and ST were measured using accelerometers at age 7 years.
Main Results:
- Higher total PA and moderate-to-vigorous PA (MVPA) at age 7 were inversely associated with fat mass index (FMI) at both ages 7 and 11.
- Sedentary time (ST) at age 7 was positively associated with FMI and inversely associated with fat-free mass index (FFMI).
- Associations between PA and adiposity were stronger in Black and South Asian children and in boys at age 11.
Conclusions:
- Higher levels of physical activity in 7-year-olds are associated with reduced adiposity at ages 7 and 11.
- Ethnic and sex differences exist in the associations between physical activity, sedentary time, and adiposity.
- Fat mass measurements offer valuable insights into ethnic variations in adiposity and activity relationships.
Objective:
To examine whether physical activity (PA) and sedentary time (ST) in primary school-aged children are associated with adiposity at the start of secondary school, and whether these associations differ by sex or ethnic group.
Design:
Nationally representative prospective cohort study.
Setting:
Children born across the UK, between 2000 and 2002.
Participants:
6497 singleton children.
Outcome Measures:
Measures of adiposity (body mass index (BMI), fat mass index (FMI) and fat free mass index (FFMI))--obtained at 7 and 11 years.
Explanatory Measures:
Total daily PA (mean counts per minute (cpm)); minutes of moderate-to-vigorous PA (MVPA); and ST. All assessed at 7 years using accelerometers.
Results:
In cross-sectional analyses, total PA was inversely associated with FMI (3.7% (95% CI 2.7% to 4.7%) reduction per 150 cpm increase), as was MVPA (4.2% (CI 3.2% to 5.2%) reduction per 20 min/day increase). Associations were stronger in black and South Asian ethnic groups. Total PA and MVPA were not associated with FFMI. ST was positively associated with FMI (1.3% (CI 0.2% to 2.3%) increase per 50 min/day increase) and inversely associated with FFMI (0.5% (CI 0.2% to 0.7%) reduction per 50 min/day increase). Longitudinally, MVPA at age 7 years remained inversely associated with FMI at age 11 years (1.5% (CI 0.4% to 2.6%) reduction per 20 min/day increase). No association was found between total PA and ST and any of the later adiposity measures.
Conclusions:
7-year-old children who are more physically active are less likely to be obese at that age and at age 11 years. These associations were particularly evident in children from black or South Asian ethnicity at age 7 years and in boys at age 11 years. Measurements of fat mass provide valuable insights into ethnic differences in associations between adiposity and activity.
