As a Mediterranean country, Croatia has Mediterranean diet incorporated into its culture. However, data in statistical yearbooks, that Croatia has been publishing since 1980s, show an increasing trend of childhood body mass and body weight that we can correlate with modern lifestyle. This phenomenon has also affected other Mediterranean countries, and appropriate and timely action is crucial if we want to prevent long-term consequences in our countries. Apart of several public health interventions that Croatian Institute of Public Health has been implementing throughout past years (national campaign "Healthy living" that includes activities such as polygons for physical activity in elementary schools, 10-minute exercise and health education is elementary and high schools, healthy menus in schools, project volunteers in parks and numerous others), and as a result of initiative by Ministry of Health, Croatia has joined European Childhood Obesity Surveillance Initiative (COSI) in its fourth round, in school year 2015/2016.
In Croatia, COSI is being carried out by Croatian Institute of Public Health with the support of Ministry of Health and Ministry of Science, Education and Sports. The initiative has started with the organization of the annual COSI meeting held in Dubrovnik, Croatia in May 2015, and continued with engagement of more than 160 elementary schools from parts of Croatia. In these schools pupils from randomly selected 2nd and 3rd grades (age 8.0-9.9 years old) will be included in the research. Field work has started in October, and will finish by the end of 2015.