PEDIATRIC ORIGINAL ARTICLE Perinatal predictors of overweight at infancy and preschool childhood: the GENESIS study G Moschonis, E Grammatikaki and Y Manios Department of Nutrition and Dietetics, Harokopio University, Athens, Greece Objective: To identify those perinatal parameters and characteristics predisposing children to an increased risk of overweight during infancy and preschool years. Design: The analyses were performed using data from the Growth, Exercise and Nutrition Epidemiological Study In preSchoolers. Subjects: A representative sample of 2374 Greek preschoolers 1–5 years old. Measurements: Anthropometric data, such as body weight, recumbent length and standing height, were obtained by using standard procedures and measuring equipment. Structured interviews were conducted with both parents to collect information on anthropometric, demographic, medical and behavioral data. Finally, children’s anthropometric data at birth, 6 and 12 months of age were recorded from their birth certificates and medical records. Results: Children born large for gestational age were 4.59 and 2.19 times more likely for being overweight at 6 and 12 months of age, respectively, than children born appropriate for gestational age. On the other hand, children that were exclusively breastfed were 0.49 and 0.54 times less likely for being overweight at 6 and 12 months of age, respectively, than children that were exclusively formula fed. Furthermore, 3- to 5-year-old children born to mothers who were both active and passive smokers during pregnancy were 1.79 times more likely of being overweight compared to children born to nonsmoking mothers. Finally, having an overweight father significantly increased the likelihood of childhood overweight at 12 months, 1–3 and 3–5 years of age. Conclusion: Our findings showed that some of the perinatal parameters and characteristics examined in the current study predict overweight at infancy, while others at preschool years. Priority should be given to size at birth, breastfeeding, maternal smoking during pregnancy and parental overweight, when developing public health strategies to reduce the prevalence of childhood overweight and related chronic disease later in life. International Journal of Obesity (2008) 32, 39–47; doi:10.1038/sj.ijo.0803764; published online 4 December 2007 Keywords: infants; preschool children; perinatal parameters; predictors Introduction Obesity represents the most frequent public health problem globally. 1 In many developed countries childhood over- weight and obesity has reached epidemic proportions, 2 as these have been doubled in the past 20 years. 3 Overweight children already show related signs of morbidity, including elevated blood pressure, cholesterol, triglycerides and insulin levels. 4 Furthermore, overweight children have a high risk for being overweight in adulthood 4–6 and to experience typical obesity-related morbidity. Recent research showed that several of the major chronic diseases of adult life including cardiovascular disease, hypertension and type 2 diabetes mellitus originate in early childhood. Thus, prevention of pediatric overweight and obesity is very important for the long-term prevention of chronic disease. The higher cost and the mixed effectiveness of therapeutic approaches 7 emphasize the need for both population- and individual-oriented preventive measures, which ideally should begin very early in life. Additional reasons that emphasize prevention in early childhood include adipocyte physiology, adiposity rebound and the limited potential for reversing metabolic changes associated with obesity in later life. 7 Although several efforts have been made to better under- stand the causes of obesity, still little is known on the exact causes or the best way to stop this adverse public health Received 28 December 2006; revised 14 October 2007; accepted 21 October 2007; published online 4 December 2007 Correspondence: Dr Y Manios, Department of Nutrition and Dietetics, Harokopio University, 70, El. Venizelou Avenue, Kallithea, Athens 176 71, Greece. E-mail: manios@hua.gr International Journal of Obesity (2008) 32, 39–47 & 2008 Nature Publishing Group All rights reserved 0307-0565/08 $30.00 www.nature.com/ijo