Joca Zurc

1. Introduction Children of 6–12 years of age experience good health in general. However, at the same time, unhealthy behaviors, such as a sedentary lifestyle, unhealthy nutrition, obesity, use of substances, and lack of hygiene, are fairly common. School-aged children also frequently report suffering from psychosomatic symptoms, poor mental health, and growing health inequality within and between countries [1,2,3].