Differentiating effects of socio-economic factors on relative weight and nutritional status in Polish schoolchildren across intergenerational changes.

ABSTRACT

OBJECTIVE: The aim of this study was an assessment of the effects of urbanisation level, family size and parental education on body mass index (BMI) and mid-upper arm circumference (MUAC) among Polish schoolchildren in cross-sectional surveys conducted between 1966 and 2012. DESIGN: The analysis involved schoolchildren measured in four Polish Anthropological Surveys (1966, 1978, 1988 and 2012). Socio-economic factors involved urbanisation level (city, town and village), family size (one child, two children, three children, four or more children), and father's and mother's education (lower and higher education). SETTING: Regions in Poland - cities Warsaw, Lodz and Wroclaw; towns Bystrzyca Klodzka, Pinczow, Siemiatycze, Wolsztyn and their rural surroundings. PARTICIPANTS: A total sample consisted of 63 757 children (31 774 boys and 31 983 girls) aged 7-18 years. RESULTS: Between 1966 and 1988, both BMI and MUAC had significantly higher values in children from cities, in families with one child and with higher parental education (P < 0·05). However, MUAC revealed significant differences between particular socio-economic groups more frequently than BMI. In 2012, urbanisation level and parental education ceased to show a differentiating effect on both indicators, while family size remained a significant social factor for both measures (BMI P < 0·05; MUAC P < 0·01). CONCLUSIONS: Since MUAC reflected socio-economic differences more frequently than BMI, it could be a more sensitive and reliable anthropometric measure revealing the effects of socio-economic factors on children's nutritional status.