The aim of the publication is to present the problem of overweight and obesity in children and adolescents, along with general health consequences resulting from the problem, based on a review of literature. Obesity and overweight in childhood and adolescence, result in problems with maintaining the right body weight in adulthood. The problem of obesity is quite complex and not only medical aspect but also cultural, economic and social aspects can be easily identified within it. Preventive and therapeutic activities undertaken in childhood could help prevent many health problems in adulthood. An effective therapy should be conducted by parents and a group of professionals. It is necessary to disseminate health promotion programs and achieve high levels of effectiveness in preventive activities among young people, which will improve the health state of obese children and reduce a growing number of children with excessive body weight.