ORIGINAL ARTICLE Prevalence of overweight, obesity, and associated risk factors among school children and adolescents in Tianjin, China Amanuel Kidane Andegiorgish & Jianhua Wang & Xin Zhang & Xinmin Liu & Hong Zhu Received: 28 September 2011 /Accepted: 15 November 2011 /Published online: 9 December 2011 # Springer-Verlag 2011 Abstract To estimate the prevalence and determinants of overweight and obesity among school children and adoles- cents (7–18 years), a cross-sectional study was conducted in Tianjin City of Northeast China. Five primary and middle schools were selected using a multistage random cluster sampling. Anthropometric measurements were taken by the research team. Then, standardized questionnaires on socioeconomic status, diet and lifestyle, parental weight and height were sent to the parents to be completed together with their child. Overall, 3,140 students were screened for overweight and associated risk factors. Body mass index classification reference proposed by the Working Group on Obesity in China was used as a screening reference to calculate the prevalence of overweight in these groups. The prevalence of overweight and obesity was found to be 12.5% and 15.7%, respectively. Logistic regression analysis (overweight compared with normal weight) showed that, overweight in children was significantly associated with male gender, parental obesity, parental educational level, mother’ s history of gestational diabetes, high birth weight, less hours of physical activity per day, urban residence, motorized transportation, and eating food not prepared at home. After adjusting for parental obesity, the odds ratio of overweight children was increased by urban residence (rural as a reference, 2.68, 2.16–3.32), positive gestational diabetes (2.76, 1.37–4.50), and fast-food/restaurant food service (2.03, 1.34–3.07). Children who walked to school and participated in outdoor activities were 54% and 63% less likely to be overweight respectively. Conclusions: The prevalence of overweight and obesity is high among school children and adolescents in Tianjin. Changes in lifestyle, high socioeconomic status, parental obesity, mother ’ s history of gestational diabetes, and high birth weight are among the highly associated risk factors of overweight. An educational approach about maintaining a healthy weight should be introduced much earlier to high-risk children, parents, and women of childbearing age. Keywords Prevalence . Overweight . Obesity . Risk factors . School children Introduction Obesity, an escalating global epidemic defined as a disease by the World Health Organization (WHO), affecting virtually both developed and developing countries of all socioeconomic status (SES) groups, including all age groups, is posing an alarming problem [1, 23]. China once with the leanest population of Asia is now rapidly catching up with the West in terms of prevalence of overweight and obesity which had occurred in a remarkably short time with an estimate of 215 million overweight and obese youngsters (2002 China health and nutrition survey) out of which 7% of those were aged 7–17 years [44]. In China, the prevalence of childhood obesity in different regions is determined by the SES, diet, and lifestyle. It varies from 3.9% to 17.6% in girls and 5.0% to 32.5% in boys of the western rural region and northern coastal cities of China, respectively [19]. A study from mainland China reported A. K. Andegiorgish : J. Wang : X. Liu : H. Zhu (*) Epidemiology Department, College of Public Health, Tianjin Medical University, Tianjin 300070, Tianjin Province, People’ s Republic of China e-mail: zhuhong@tijmu.edu.cn X. Zhang Department of Child, Adolescent and Women’ s Health, College of Public Health, Tianjin Medical University, No 22. Qixiangtai Road, Heping District, Tianjin, People’ s Republic of China Eur J Pediatr (2012) 171:697–703 DOI 10.1007/s00431-011-1636-x