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Associations of extracurricular physical activity patterns and body composition components in a multi-ethnic
Lander S M M Bosch1, Jonathan C K Wells2, Sooky Lum3
1Department of Geography, University of Cambridge, Downing Place, Cambridge, CB2 3EN, UK. lsmmb2@cam.ac.uk.
Insights
Active commuting in children is linked to lower Body Mass Index (BMI) and Fat Mass Index (FMI). More frequent sports participation correlates with greater fat-free mass, independent of ethnicity and socioeconomic factors.
Area of Science:
- Pediatric obesity research
- Body composition analysis
- Public health and physical activity
Background:
- Childhood obesity is a significant public health concern.
- Body Mass Index (BMI) is a common metric, but Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI) offer more detailed body composition insights.
- Ethnic variations in physical activity and body composition necessitate nuanced analysis in multi-ethnic populations.
Purpose of the Study:
- To investigate the associations between different physical activity types and body composition metrics (BMI, FMI, FFMI) in primary schoolchildren.
- To examine these associations across diverse ethnic groups in London.
- To control for socioeconomic factors and understand their influence on the observed relationships.
Main Methods:
- Cross-sectional study of 2171 primary schoolchildren (aged 5-11 years) from Black, South Asian, and White/Other ethnic backgrounds.
- Analysis of Body Mass Index (BMI), Fat Mass Index (FMI), and Fat-Free Mass Index (FFMI) z-scores.
- Multilevel mixed-effects ordered logistic modeling, adjusting for age, sex, and socioeconomic status.
Main Results:
- Active commuting was significantly associated with lower BMI and FMI z-scores compared to passive commuting.
- Children participating in sports less than weekly showed lower BMI and FFMI z-scores compared to daily participants.
- Complete inactivity showed a trend towards higher BMI and FMI z-scores, but not FFMI z-scores.
Conclusions:
- Active commuting is objectively linked to reduced adiposity in children.
- Increased participation in extracurricular sports correlates with greater fat-free mass accrual.
- These physical activity-body composition relationships are independent of ethnicity and socioeconomic status.
Background:
Body Mass Index (BMI) is a common outcome when assessing associations between childhood overweight and obesity and physical activity patterns. However, the fat and fat-free components of BMI, measured by the Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI), may show contrasting associations with physical activity, while ethnic groups may vary in both physical activity patterns and body composition. Body composition must therefore be evaluated when assessing the associations between childhood overweight and obesity and physical activity in multi-ethnic populations.
Methods:
This cross-sectional study investigated associations of BMI, FMI and FFMI z-scores with extracurricular physical activity for 2171 London primary schoolchildren (aged 5-11 years) of black, South Asian and white/other ethnicity. Multilevel mixed-effects ordered logistic modelling was used, adjusting for age, sex and family and neighbourhood socioeconomic status as potential confounders.
Results:
Controlling for ethnicity and individual, family and neighbourhood socioeconomic confounders, actively commuting children had significantly lower Odds Ratios for being in high BMI (Odds Ratio (OR) = 0.678; 95 % Confidence Interval (CI) = 0.531 - 0.865; p - value = 0.002) and FMI z-score groups (OR = 0.679; 95 % CI = 0.499 - 0.922; p = 0.013), but not FFMI z-score groups, than passive commuters. Children doing sports less than once a week had lower Odds Ratios for being in high BMI (OR = 0.435; 95 % CI = 0.236 - 0.802; p = 0.008) and FFMI (OR = 0.455; 95 % CI = 0.214 - 0.969; p = .041) z-score categories compared to daily active children. Differences in FMI between groups did not reach the significance threshold. A trend towards statistical significance was obtained whereby children's complete inactivity was associated with higher odds for being in higher BMI (OR = 2.222 : 95 % CI = 0.977 - 5.052; p = .057) and FMI z-score groups (OR = 2.485 : 95 % CI = 0.961 - 6.429; p = .060). FFMI z-scores did not show a similar trend with complete inactivity.
Conclusions:
Active commuting was objectively associated with lower adiposity, while more frequent extracurricular sports participation was correlated with greater fat-free mass accretion. These relationships were independent of ethnicity and individual, family or neighbourhood socioeconomic confounding factors.
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