The theme of World Kidney Day 2017 is 'kidney disease and obesity: healthy lifestyle for healthy kidneys'. To mark this event, Nature Reviews Nephrology invited five leading researchers to describe changes in the epidemiology of obesity-related kidney disease, advances in current understanding of the mechanisms and current approaches to the management of affected patients. The researchers also highlight new advances that could lead to the development of novel treatments and identify areas in which further basic and clinical studies are needed.