Relationship between physical activity levels and body fat of children aged 8–9, from UK schools in low socioeconomic areas

Relevance: Increasing levels of obesity, sedentary lifestyles and lower levels of physical activity (PA) in children is concerning both in the UK and globally. This is particularly important in low socioeconomic status (SES) areas, where lower levels of engagement with public health initiatives have been identified. Health behaviour patterns in childhood are important for long-term health and well-being. It is therefore important to understand PA behaviours in children from low SES areas and to explore possible relationships with obesity.Purpose: This study aimed to measure current levels of PA and their relationship with obesity in primary school children in low SES of a West Midlands, UK city.The secondary aim was to identify any differences between PA levels on school days compared to the weekend.Methods/analysis: This cross-sectional observation study was employed, following ethical approval, from a Coventry University, Ethics Committee. A purposive sample of 128 children (8–9 years) were recruited from 4 schools in low SES areas from one West Midlands city. Height and mass of each child were measured, from which BMI was calculated (kg/m2). Body fat (%) was estimated using foot–foot bioelectrical impedance. Each child was fitted with a non-dominant, wrist-worn GENEActive Accelerometer for 4 days (2 weekdays and 2 weekend days). Data which met inclusion criteria (>10 hours wear time, per day) was included in the analysis, leaving a final sample of 71 children (37 male, 34 female, 47 of Caucasian origin). Minutes spent in sedentary, light, moderate and vigorous PA were calculated according to Phillips et al. (2013). Comparisons were made between days for mean % time spent in each level of PA across using repeated measures ANOVA. Pearson's correlations were calculated for body composition variables (BMI, % body fat) and sedentary, light, moderate and vigorous PA.Results: 71.8% of children met the WHO global guideline of 60 minutes of moderate-vigorous PA (MVPA) per day. Children spent significantly more time in sedentary behaviour on Sundays (57.3% vs. (49.7–51.9%), p <.01) and significantly less time in vigorous activity on Sundays compared to each of the other 3 days (p <.05). Increasing % time in MVPA was negatively correlated with both BMI (−.42, p <.001) and body fat % (−.58, p <.001).Discussion and conclusions: Nearly a third of recorded 8–9 year-old UK school children in low SES areas were not meeting global PA guidelines. Increasing MVPA in children may reduce body fatness, considering the moderate negative correlation reported between the two. Further interventional studies would be required to confirm this. Furthermore, the findings suggest that interventions may need to focus on increasing levels of MVPA and reducing sedentary behaviours on Sundays in children from low SES areas. The mechanisms for successful implementation require further exploration in this population. Multi-factorial causation also requires consideration.Impact and implications: The potential for Physiotherapists to engage in public health practice has long been recognised. This collaborative study by Physiotherapists and Exercise Scientists provides baseline data for PA levels in UK school children in low SES areas, essential to test subsequent interventions, and to inform local policy formation and funding bids.