Keywords: end stage renal disease, dialysis, body composition, physical activity, quality of life

This thesis focuses on body composition, physical activity and quality of life in pre-dialysis and dialysis patients. The transitional phase of pre-dialysis to dialysis and the first six months after starting dialysis were also studied. Although this is one of the most critical phases in the lives of chronic renal disease patients, only few studies have been conducted into this subject. The findings of this thesis clearly show the importance of gaining more insight into changes and risks that occur after starting dialysis treatment in order to reduce the risk of common complications.