The Influence of Secular Trends in Body Height and Weight on the Prevalence of Overweight and Obesity among Chinese Children and Adolescents / 生物医学与环境科学（英文）

ABSTRACT

<p><b>OBJECTIVE</b>To explore the influence of secular trends in body height and weight on the prevalence of overweight and obesity among Chinese children and adolescents.</p><p><b>METHODS</b>The data were obtained from five cross-sectional Chinese National Surveys on Students' Constitution and Health. Overweight/obesity was defined as BMI-for-age Z-score of per the Wold Health Organization (WHO) reference values. Body height and weight for each sex and age were standardized to those reported in 1985 (standardized height SHY; standardized weight SWY) and for each sex and year at age 7 (standardized height SHA; standardized weight SWA) using the Z-score method.</p><p><b>RESULTS</b>The prevalence of overweight/obesity in Chinese children was 20.2% among boys and 10.7% among girls in 2010 and increased continuously from 1985 to 2010. Among boys and girls of normal weight, SHY and SHA were significantly greater than SWY and SWA, respectively (P < 0.001). Among boys and girls with overweight/obesity, SHY was significantly lower than SWY (P < 0.001), and showed an obvious decreasing trend after age 12. SHA was lower than SWA among overweight boys aged 7-8 years and girls aged 7-9 years. SHY/SHW and SHA/SWA among normal-weight groups were greater than among overweight and obese groups (P < 0.001).</p><p><b>CONCLUSION</b>The continuous increase in the prevalence of overweight/obesity among Chinese children may be related to a rapid increase in body weight before age 9 and lack of secular increase in body height after age 12.</p>