Objectives: To assess the magnitude of overweight and obesity, and its associated socio-demographic factors in adolescents in Xi'an city, China.
Methods: A total of 1804 adolescents attending junior high schools in Xi'an City (age: 11-17 years) were included in this cross-sectional study. Body mass index using IOTF cut-offs defined overweight and obesity. Socio-demographic information was collected from the parents of the survey participants using self-administered, structured and pre-coded questionnaires.
Results: Overall, 16.3% of adolescents were overweight or obese, but there was a marked gender difference in the prevalence with 19.4% (95% CI: 15.6% - 23.7%) of boys versus 13.2% (95% CI: 10.0% - 16.4%) ofthe girls being overweight or obese. In a multivariate model, age, residence, household wealth, and parents' body mass index were significantly associated with being overweight/obese (p < 0.05). After adjusting for age and gender, the odds of an adolescent being overweight or obese was 2.7 times (95% CI: 1.8 - 4.0) higher in urban areas compared to rural areas; and 1.6 times (95% CI: 1.04 - 2.5) higher for adolescents from rich compared to poor families. An adolescent with one or both parents being overweight was 1.8 times (95% CI: 1.3 - 2.5) more likely to be overweight themselves compared to those with normal weight parents.
Conclusions: 1) Overweight and obesity is a major public health problem in adolescents in Xi'an City and is likely to increase rapidly in the near future; 2) Overweight and obesity is more prevalent in younger boys from richer families living in urban districts and whose parents were either overweight or obese.