ORIGINAL ARTICLE Prevalence of overweight/obesity among 7-year-old children—WHO Childhood Obesity Surveillance Initiative in Slovakia, trends and differences between selected European countries Ľubica Tichá 1 & Valéria Regecová 2 & Katarína Šebeková 3 & Darina Sedláková 4 & Jana Hamade 5 & Ľudmila Podracká 1 Received: 25 September 2017 /Revised: 22 March 2018 /Accepted: 27 March 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract The objectives of this study were (1) to assess the prevalence and time trends of overweight/obesity in Slovak children by applying WHO, IOTF, and the national criteria; (2) to compare the prevalence between selected European countries; and (3) to evaluate the central obesity by the waist-to-height ratio. The survey was performed within the WHO European Childhood Obesity Surveillance Initiative. The weight, height, waist, and hip were measured in 2795 children at the age of 7–7.99 years (50.1% boys; 55.5% in rural areas). The prevalence of overweight/obesity was determined using the LMS Growth. In boys, the prevalence of overweight/obesity was 17.1/14.9% according to WHO, 13.8/8.8% according to IOTF, and 9.9/8.8% according to the national criteria. Among girls, the prevalence reached 15.1/11.1%, 12.6/8.1%, and 7.5/9.5%, respectively. These rates corresponded to the average of the European countries. Central obesity was identified in 76.9% of overweight/obese, but also in 5.9% normal-weight subjects. Conclusion: While overweight has increased by 3% the prevalence of obesity has doubled since 2001. The rise culminated approximately 6 years ago and has not increased since then. The body constitution differences should be considered when comparing the prevalence of overweight/obesity between populations and/or individuals. What is Known: • Knowledge of the prevalence of overweight/obesity is seminal for effective implementation of programs focusing on the reduction of incidence and prevalence of obesity in early childhood. What is New: • The most numerous and representative study on the prevalence of overweight/obesity in 7-year-old children involving 2795 (5%) of peers living in Slovakia. • The prevalence of obesity in Slovakia falls within the range of average rate of the European countries. Central obesity was identified in almost 20% subjects. Keywords Overweight/obesity . Children . Prevalence and trends in European countries Communicated by Mario Bianchetti * Ľubica Tichá ticha.lubica@gmail.com Valéria Regecová valeria.regecova@gmail.com Katarína Šebeková kata.sebekova@gmail.com Darina Sedláková sedlakovad@who.int Jana Hamade jana.hamade@uvzsr.sk Ľudmila Podracká podracka12@yahoo.com 1 National Institute of Children’ s Diseases and Faculty of Medicine of Comenius University, Limbová 1, 833 40 Bratislava, Slovakia 2 Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, 811 09 Bratislava, Slovakia 3 Institute of Molecular Biomedicine, Faculty of Medicine of Comenius University, Sasinkova 4, 811 08 Bratislava, Slovakia 4 WHO Country Office in Slovakia, Limbová 2, 837 52 Bratislava, Slovakia 5 Public Health Authority of the Slovak Republic, Trnavská cesta 52, 826 45 Bratislava, Slovakia European Journal of Pediatrics https://doi.org/10.1007/s00431-018-3137-7