Socioenvironmental conditions and nutritional status in urban and rural schoolchildren

Abstract

We analyzed the nutritional status of urban and rural schoolchildren from Mendoza (Argentina), but avoided rural and urban categorization by generating subpopulations as a function of their socioenvironmental characteristics. We transformed weight and height data into z-scores using the CDC/NCHS growth charts; defined underweight, stunting, and wasting by z-scores of less than -2 SD; and calculated overweight and obesity, according to the cutoff proposed by the International Obesity Task Force. Socioenvironmental characteristics included housing, public services, parental resources, and farming practices; we processed these variables by categorical principal-component analysis. The two first axes defined four subgroups of schoolchildren: three of these were associated with urban characteristics, while the remaining subgroup was considered rural. Nutritional status differed across groups, whereas overweight was similar among the groups and obesity higher in urban middle-income children. Urban differences were manifested mainly as underweight, but rural children exhibited the greatest stunting and wasting. Thus, the negative effects of environment on nutritional status in children are not restricted to poor periurban and rural areas, though these are indeed unfavorable environments for growth: some urban families provide children with sufficient quantity and diversity of foods to expose them to obesity. By contrast, the more affluent urban families would appear to have greater possibilities for allowing their children to adopt a healthy life-style. Although the causes of differences in nutritional status between middle- and high-income urban groups are not clear, these determinants probably involve economic as well as educational influences.