Moderate–vigorous physical activity and body fatness in Chinese urban school children

Abstract

BACKGROUND: The exact relation between moderate-vigorous physical activity (MVPA) and body fatness in children has yet to be fully defined. This study examined the relationship between MVPA and body fatness in Chinese urban school children aged 9-11 years, in an 8 month longitudinal study. METHODS: Two hundred and ten children (aged 9-11 years; 97 boys and 113 girls) were recruited from two public primary schools in the Beijing urban area. The baseline and the 8 month follow-up percent body fat (fat%), fat mass (FM), body mass index (BMI), waist size, hip size and the waist : hip ratio were investigated as measures of body fatness. Habitual MVPA level (activity-related energy expenditure, AEE) was measured using a validated self-report questionnaire recall. RESULTS: Nine-year-old girls who were in the top quartile for MVPA had significantly lower fat% than other girls at the same age (P < 0.05); 10-11-years girls who were in the top quartile for MVPA had significantly less increase in all of the indices of body fatness (P < 0.05). There was no difference in fat% between the highly physically active (top quartile for MVPA) and less active 9-11 year boys in both cross-sectional and longitudinal statistical analyses. CONCLUSIONS: Highly physically active girls had lower fat% and less increase in body fatness. In light of world trends showing increasing childhood obesity, this study supports the hypothesis that MVPA might be effective in fighting excess body fat gain in Chinese school-age girls.