BMC Public Health Research article Predictors of overweight and obesity in five to seven-year-old children in Germany: Results from cross-sectional studies Christian J Apfelbacher*1,2,3, Adrian Loerbroks4, John Cairns1, Heidrun Behrendt5, Johannes Ring6 and Ursula Krämer7 BioMed Central Open Access Address: 1The London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London WC1E, UK, 2University Hospital Heidelberg, Department of Clinical Social Medicine, Thibautstr. 3, 69115 Heidelberg, Germany, 3Divison of Public Health and Primary Care, Brighton and Sussex Medical School, University of Brighton, Falmer BN1 9PH, UK, 4Institute of Psychology, University of Heidelberg, Hauptstrasse 47-51, 69117 Heidelberg, Germany, 5Division of Environmental Dermatology & Allergy GSF/TUM, ZAUM (Centre for Allergy and Environment), Technical University Munich, Biedersteinerstraße 29, 80802 Munich, Germany, 6Department of Dermatology and Allergy Biederstein, Technical University Munich, Biedersteiner Straße 29, 80802 Munich, Germany and 7Institut für Umweltmedizinische Forschung at the Heinrich-Heine- University Düsseldorf, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany Email: Christian J Apfelbacher* - christian.apfelbacher@web.de; Adrian Loerbroks - adrian.loerbroks@psychologie.uni-heidelberg.de; John Cairns - john.cairns@lshtm.ac.uk; Heidrun Behrendt - heidrun.behrendt@lrz.tu-muenchen.de; Johannes Ring - johannes.ring@lrz.tu- muenchen.de; Ursula Krämer - kraemeru@uni-duesseldorf.de * Corresponding author Published: 21 May 2008 BMC Public Health 2008, 8:171 doi:10.1186/1471-2458-8-171 This article is available from: http://www.biomedcentral.com/1471-2458/8/171 Received: 15 November 2007 Accepted: 21 May 2008 © 2008 Apfelbacher et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Childhood obesity is a serious public health problem and epidemiological studies are important to identify predictive factors. It is the aim of this study to analyse factors associated with overweight/obesity in samples of German children. Methods: 35,434 five to seven year-old children (50.9% boys) participated in cross-sectional studies between 1991 and 2000 in several rural and urban areas in East and West Germany. Weight and height were measured and body mass index was calculated. International cut-off points, recommended by the International Obesity Task Force, were used to classify childhood overweight and obesity. Predictive modelling was employed to analyse independently associated factors, using logistic regression to adjust for confounding. Results: 15.5% were overweight, and 4.3% were obese. Female sex, other than German nationality, smoking in the living place and increasing birth weight were found to increase the odds of overweight and obesity, while increasing educational level, living space > 75 m2 and breastfeeding for more than three months were inversely associated. Conclusion: The findings add to the evidence informing public health action, both through health promotion strategies (promoting breastfeeding, tackling smoking) and wider societal change management (addressing children from migrant families and families with low educational level). Page 1 of 10 (page number not for citation purposes)