Child overweight and undernutrition in Thailand: is there an urban effect?

An urban advantage in terms of lower risk of child undernutrition has been observed in many developing countries, but child obesity is often more prevalent in urban than rural areas. This study aimed to assess whether urban-rural disparities in undernutrition and obesity were attributable to concentrations of socioeconomically advantaged children into urban communities or to specific aspects of the urban environment. A sample of 4610 children ages 2-10 years was derived from the 2004 Round of the Kanchanaburi Demographic Surveillance System, monitoring health and demographic change in the province of Kanchanaburi, Thailand. We used multi-level logistic regression to model the odds of short stature, underweight, and obesity for children in 102 communities. Models tested whether child socioeconomic conditions accounted for urban-rural disparities or if aspects of the social and physical environment accounted for disparities, adjusting for child characteristics. 27.8% of children were underweight, while 19.9% had short stature, and 8.3% were obese. Bivariate associations showed urban residence associated with lower risk of undernutrition and a greater risk of obesity. Urban-rural disparities in odds of short stature and underweight were accounted for by child socioeconomic characteristics. Urban residence persisted as a risk factor for obesity after adjusting for child characteristics. Community wealth concentration, television coverage, and sanitation coverage were independently associated with greater risk of obesity. Undernutrition was strongly associated with household poverty, while household affluence and characteristics of the urban environment were associated with odds of obesity. Further research is needed to characterize how urban environments contribute to children's risks of obesity in developing countries.