title: [Study on the prevalence of childhood overweight and underweight, and the association with family socio-economic status (SES)].
abstract: OBJECTIVE
  To analysis the prevalence of childhood overweight and underweight, and the association with family socio-economic status (SES) over years.
  
  
  METHODS
  Children aged under 18 years in nine province of China were analyzed from the datasets of 1991 - 2009 China Health and Nutrition Survey. SES were indicated bu per capita family income and parental tertiary education. The time trends of the associations between SES and childhood overweight and underweight were analyzed by Logistic regression, and the correlation between SES and childhood BMI were estimated by Quantile regression.
  
  
  RESULTS
  The prevalence of overweight and underweight have increased by 1.22 times and 0.39 times, respectively. Logistic regression results show that family income per capita changed from a protective factor for childhood overweight into a risk factor over almost two decades, while parental tertiary education increased the odds more prominent. For childhood underweight, the SES indicators show no statistically significant effect. Estimations from Quantile regression also show the same pattern with Logistic results.
  
  
  CONCLUSIONS
  Both of childhood overweight and underweight were affected by family income and parental tertiary education. A comprehensive prevention and control measures of family intervention should be taken.
authors.forename: Wen
authors.initials: W
authors.lastname: Tang
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Pan
mesh_terms: D002648:Child; D002681:China / Q000453:epidemiology; D006801:Humans; D007182:Income; D016015:Logistic Models; D009749:Nutrition Surveys; D050177:Overweight / Q000453:epidemiology*; D010290:Parents; D015995:Prevalence; D012307:Risk Factors; D012923:Social Class; D012959:Socioeconomic Factors; D013851:Thinness / Q000453:epidemiology*