Obesity is one of the main topics of all news, portals and conversations. It is closely related to many diseases that arise precisely because of leading an unhealthy lifestyle and insufficient physical activity. The data presented in the research of this thesis are worrying precisely because it concerns children. We can see around us every day how much this disease is spreading. There is more and more obese children already in lower grades. Lack of time and fatigue are persistently blamed for an unhealthy diet and lack of physical activity, but in fact it's all about timing and planning meals and activities. Walking ais a great activity for keeping body weight under control or losing it when necessary. In addition to walking, you can also bike, rollerblade, swim... All of these options are available and very easy to "use", and the easiest is to walk. Running is one of the activities that can leave excellent results. It is important to be active and eat a variety of foods and to eliminate those that harm us or at least eat them in moderation. No matter how much we talk about these topics, it is still not enough. People still don't believe and don't care about being told how damaging they are to their health until it happens.