title: [The current status of physical activity in urban school-aged children and its association with obesity].
abstract: OBJECTIVE
  To understand the current status of physical activity among urban school-aged children and its association with obesity.
  
  
  METHODS
  295 pupils, aged 9 to 13 years were selected, using the method of convenience sampling. Data on anthropometric measurements was collected, including weight and height. Questionnaire survey, clinic examination, dietary investigation of school lunch and surveillance on 7-day physical activity by pedometers, were done and Multi-linear regression was used to analyze the relationship between waist to height ratio (WHtR), fat mass percentage (FMP), body mass index (BMI) and physical activity. Single-variable and multiple non-conditional logistic regression modeling were applied to analyze data collected from obesity and physical activities.
  
  
  RESULTS
  15.5% of boys and 13.1% of girls reached 60 minutes per day of 'moderate-vigorous physical activities'. Compared with normal children, overweight/obesity children showed an increase of sedentary activity time, total energy expenditure, and energy expenditure of physical activity. With the increase of 1 hours daily on going to school by private car, WHtR and FMP increased by 0.01 and 2.06 units, respectively. FMP increased 0.89 units among with the increase of sedentary activity time, 1 hour daily. BMI and the intake of leafy vegetables (eg. spinach, cabbage) showed a negative correlation. As the frequency of leafy vegetables consumption increased once weekly, BMI fell 0.10 units. After adjustment for sex and age, the risk of overweight/obesity was 3.82-fold (95%CI: 1.17-12.47) among children who had sedentary activity time more than 120 min/d, than those having less than 120 min/d.
  
  
  CONCLUSIONS
  Our data showed that children's daily physical activity was not enough and measures should be taken to decrease the time of sedentary behavior and increase the energy expenditure through physical activities.
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Guimin
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Zhongjian
authors.initials: Z
authors.lastname: Su
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Junting
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Yinkun
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Linghui
authors.initials: L
authors.lastname: Meng
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China. Email: jiemi@vip.163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Mi
mesh_terms: D050154:Adiposity; D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology*; D014505:Urban Population; D065927:Waist-Height Ratio