Objectively assessed physical activity and weight status in Maltese 11-12 year-olds

The objectives of the study were to identify levels of physical activity and sedentary time and assess how they differ by weight status in Maltese boys and girls. Participants were 234 Maltese children aged 11-12 years, of which 187 (80%) provided complete data. Physical activity was assessed using accelerometry and weight status determined through gender-specific age-adjusted Body mass index (BMI). Self-reported mode of transport to school, TV and computer time, gaming and mobile phone use were assessed by questionnaire. Total physical activity was generally very low and significantly lower for girls than boys at all times on weekdays and on weekends till 7 pm. Overweight and obesity prevalence was 27% and 18.6%, respectively. Differences in overall physical activity were observed between non-overweight, and overweight and obese boys (p=0.003). Differences in moderate to vigorous intensity physical activity (MVPA) in boys were significant across all weight categories (p=0.001) and in girls (p=0.020) between the overweight (27.6 min), the non-overweight (26.4 min) and the obese (18.9 min). For weekdays, mean physical activity differences (p=0.013) were observed between non-overweight (515.5 cpm) and obese boys (416.4 cpm). Differences in MVPA were found (p=0.038) between non-overweight (4.4 min) and obese boys in the 6 am-3 pm period. Differences were also found between overweight (13.2 min) and obese girls (8.1 min) (p=0.024) in that period. On weekends, mean physical activity differences were found between non-overweight and overweight boys from 8 am-7 pm but not for girls. Physical activity levels in this sample were very low when compared to recommended levels, while the prevalence of overweight and obesity and sedentary time were high. Girls are significantly less active than boys throughout the week. Activity level differences and patterning across the day and week were related to weight status with obese children showing markedly less activity. These results suggest that we need to provide more opportunities for overweight and obese children to be active throughout the week, with a particular emphasis on physical activity during school hours.