[The association between body mass index, waist circumference with body fat percent, and abdominal fat rate in overweight and obese pupils].

Objective: To study the association between body mass index(BMI), waist circumference (WC) with body fat percent, and abdominal fat rate in overweight and obese pupils.

Methods: Using convenience sampling, two primary schools of Dongcheng district in Beijing were selected in May 2010. A total of 162 overweight and obese pupils graded from 2 to 5 who met the criteria of overweight and obese were recruited based on the physical exam record of the school medical department in April.

[Influence of diet behaviors on height among children and adolescents in China: a multiple level analysis].

Objective: To categorize growth and development stages among children and adolescents based on height, and to explore the influences of diet behaviors on height during different growth and development stages.

Methods: Children and adolescents (7 to 18 years) with normal weights were selected using "Reference Norm for Screening Overweight and Obesity in Chinese Child and Adolescent" set up by WGOC in 2003 and "Reference Norm for Screening Underweight in Chinese Child and Adolescent" from the "2010 National Physical Fitness and Health Surveillance" data, and the variables of height and diet behaviors sorted. The growth and development stages were categorized using the hierachical cluster analysis, and the multilevel model was used to analyze influences of diet behaviors on height at different growth and development stages.

Trends in blood pressure and body mass index among Chinese children and adolescents from 2005 to 2010.

Background: The prevalence of obesity, based on body mass index (BMI), among Chinese children and adolescents has increased for decades, but the relationship between trends in blood pressure (BP) and increasing BMI has not been studied.

Methods: BMI and BP measurements of 391,982 children aged 7-17 years were obtained from surveys in 2005 and 2010. The mean change and 95% confidence intervals (CIs) of BP were calculated, and the association between BMI and BP was assessed by using analysis of covariance and direct adjustment with the BMI distribution of 2005 survey.