High Prevalence of Obesity but Low Physical Activity in Children Aged 9–11 Years in Beijing

OBJECTIVE: To investigate the prevalence and associated factors of childhood overweight/obesity in the Shunyi district of Beijing, China. METHODS: This study adopted a cross-sectional survey and included 10,855 children aged 6–18 years in the Shunyi district of Beijing, China. Analyses were stratified by age group (6–8, 9–11, 12–14, and 15–18 years). RESULTS: The prevalence of overweight and obesity among children aged 6–18 years was high with 17.62% and 29.05% in boys, 17.57% and 18.04% in girls, respectively. Both boys and girls aged 9–11 years had the highest rate of obesity in comparison with the other age groups, though the differences in children aged 9–11 years and 12–14 years were not statistically significant. Compared with age 6–8 years, age 9–11 years (OR=1.59, 95% CI 1.41–1.79, P<0.01) and 12–14 years (OR=1.26, 95% CI 1.48–1.73, P<0.01) were independently positively associated with obesity. Importantly, in all subjects, the percentages of being physically active (exercise time ≥120 minutes/week) were lower in children aged 9–11 years in comparison to children in other age groups. This phenomenon remained when this comparison was performed respectively in the normal-weight, overweight, and obesity groups. Even after adjustment for other potential confounders, the probability of being physically active (exercise time ≥120 minutes/week) was lower in children aged 9–11 years (OR=0.86, 95% CI 0.78–0.94, P<0.01), but higher in children aged 12–14 years (OR=1.91, 95% CI 1.69–2.17, P<0.01) and aged 15–18 years (OR=2.22, 95% CI 1.85–2.66, P<0.01), when compared with children aged 6–8 years. CONCLUSION: Children aged 9–11 years had a higher prevalence of obesity, but a lower percentage of being physically active. Targeted intervention programs in this key group are needed to address this problem in China.