Childhood obesity in developing countries: epidemiology, determinants, and prevention

Environmental factors associated with overweight and obesity in taiwanese children

BACKGROUND

We explored the relationship among sociodemographic, behavioural, household environmental and perinatal factors, and risks of childhood overweight and obesity in Taiwan.

METHODS

A total of 7930 children aged 9 to 14 years were recruited from 14 randomly selected Taiwanese communities in 2007 and 2010. Height and weight were measured using standard protocols during school visits. Questionnaires that contained children's family information, birth conditions, exercise habits and household environmental factors were answered by the parents. Associations between risk factors and childhood overweight and obesity were estimated through odds ratio and 95% confidence interval from mixed models.

RESULTS

In this cohort, 32.3% of the children were overweight and 17.5% were obese. Male gender, high birthweight, exposure to in utero maternal smoking and current exposure to household environmental tobacco smoke (stronger effect of maternal than paternal smoking) were positively associated with childhood overweight/obesity. In contrast, higher parental education level, number of siblings, active exercise habits and taking vitamins were associated with reduced risks of childhood obesity. Birthweight revealed a J-shaped relationship with the probability of childhood overweight/obesity.

CONCLUSIONS

This study uncovers several modifiable risk factors for childhood overweight and obesity, and parents are encouraged to provide an anti-obesity environment such as quitting smoking, controlling birthweight of child during pregnancy and building up exercise habits.

Gender Differences Time Trends for Metabolic Syndrome and Its Components among Tehranian Children and Adolescents

Aims. To investigate the trend of metabolic syndrome and its components in Tehran children and adolescents during a median followup of 6.6 years. Methods. Data from 1999-2001 (phase I), 2002-2005 (phase II), and 2006-2008 (phase III) of the Tehran, Lipid and Glucose Study were analyzed (n = 5439; age 6-18 years) for the trend of metabolic syndrome (MetS) and its components. General estimation equation (GEE) models were used to analyze this correlated data. Results. The crude prevalence of MetS for boys at baseline was 13.2%, which increased to 16.4% in the third phase. In girls, the prevalence of Mets decreased from 11.8% at baseline to 6% during followup. The odd ratios (OR) of obesity over the whole study period were raised in both sexes. The OR of abdominal obesity increased significantly in boys, but no change was observed in girls. No significant OR was observed in boys, while OR for MetS was shown to have a decreasing trend in girls during the followup. In the three time points, the ORs of MetS decreased significantly in girls but no significant difference was observed in boys. Conclusion. Inspite of increasing trend for obesity in both sexes, the trend of MetS decreased in girls and was relatively stable in boys, in Tehranian children, and adolescents.