Nowadays, the rate of obesity among children in primary education is increasing. More and more resources and efforts are being invested in solving the problem of obesity because it is becoming an increasingly serious public health problem. It is necessary to establish prevention strategies against obesity for the whole family, including pregnant women. One of the more important measures to prevent obesity in children is to limit the consumption of fast food, sweets, and drinks, with an emphasis on the proper selection and availability of nutritious meals and water. Parents must be aware of the value of preparing regular, daily meals that are nutritionally and energetically adapted to the needs of children. The selection of nutritionally nutritious foods is as important in the prevention of obesity as physical activity. Considering the age in which we live, it is necessary to encourage children to participate in sports activities and spend time outside. The paper reviews the results of research conducted by the World Health Organization with the aim of pointing out the ubiquitous problem of obesity among school-aged children. Research by the World Health Organization, or the European Initiative for Monitoring Childhood Obesity, enabled an overview of the frequency of obesity in the countries of the European Union and beyond. The goal of the research was to gain insight into the number of obese children within the states that participated in the research. In this way, an overview of dietary habits such as breakfast consumption, consumption of fresh fruits and vegetables, and consumption of sweetened beverages daily was given. The importance of physical activity, which is one of the factors influencing obesity, was also taken into account. The purpose of this paper is to raise awareness of the growing problem of childhood obesity and the need for active involvement of families as well as all social entities in suppressing the further increase in the number of obese children.