Age 6 7 8 9 10 11 12 13 Total Childhood Early adolescent Urban Number 35 53 89 67 80 96 85 48 553 324 229 OW(n) 9 10 12 10 9 17 14 9 90 (22.2%) 50 40 OB(n) 2 2 2 5 2 4 1 1 19 (3.8%) 13 6 Rural Number – – 30 30 30 33 38 33 194 123 71 OW(n) – 4 5 9 7 2 5 – 32 (16.49%) 25 7 249 OB(n) – 5 1 0 0 1 1 – 8 (4.12%) 6 2 Eur J Pediatr (2012) 171:245–251 Table 6 Prevalence of overweight and obesity in girls based on IOTF criteria [8] by place of residence and age IOTF International Obesity Task Force, OW(n) number of overweight, OB(n) number of obesity in urban boys in comparison with other groups in which the values were similar (Fig. 1). Discussion Overweight and obesity pose a serious social and health problem in many developed and developing countries [2, 9, 19]. Despite economic, social, cultural and religious differences among them, overweight and obesity are becoming a widespread issue common for all infrequently distant countries. The authors’ own research on the incidence of overweight and obesity that was carried out in 2009 in the group of children from Cracow diagnosed 28% of boys as overweight and 7% as obese. In girls, 16.2% were overweight and 3.6% obese. Comparing the authors’ own results with the ones acquired on the basis of a research project performed in three cycles in Cracow in 1971, 1983 and 2000 [6] a distinct increase in the prevalence of overweight and obesity in children and adolescents can be observed. In the years 1971– Fig. 1 Prevalence of overweight and obesity in gender groups by place of residence 2000, the incidence of overweight and obesity in children from Cracow doubled from 7.5% to 15.2% in boys and from 6.5% to 11.8% in girls. The results obtained in 2009 revealed a further increase in the percentage of overweight and obese children reaching 35% in boys (28% overweight (OW) and 7% obesity (OB)) and almost 20% in girls (16.2% OW and 3.6% OB) [6]. A higher percentage of obese children regardless of the gender of the examined subjects was observed in younger groups (6–12 years of age in boys and 6–10 years in girls). Similar correlations are found in the publication by Jebb et al. [11] or Chrzanowska et al. [6]. Alarming is the fact that the percentage of obese children increased dramatically from 1.04% in boys and 0.20% in girls in 1971 to 7% in boys and 3.6% in girls in 2009 [6]. A quick increase in the prevalence of obesity has been observed in Germany [14]. During the period of 2003– 2006, the number of children diagnosed as obese doubled. Similarly, disturbing statistics are reported by Zimmerman et al. [23]. In Switzerland in the years 1990–2002, the percentage of obese children aged 6–12 years increased from 0.61% to 3.8% in boys and from 0.8% to 3.7% in girls. On the basis of a continuous research within China Health and Nutrition Survey performed on school children and carried out in eight provinces in the years 1991–1997, the occurrence of obesity depending on the place of residence was determined. In urban areas, the incidence of overweight increased from 7.7% to 12.4%, whereas in rural areas the increase was lower and changed from 5.9% to 6.4% [22]. Chrzanowska and Łaska-Mierzejewska [7] analysed the prevalence of overweight and obesity in girls living in rural areas in four regions of Poland. They observed that the incidence of overweight and obesity had increased by 7.4% in the years 1987–2001. Many authors seek the causes of an increasing prevalence of overweight and obesity in economic and cultural changes that have taken place in Poland following the emergence of a