Low-protein diets have been advocated for many decades as the cornerstone in the treatment of chronic kidney disease. Initially, the low intake of protein was used to reduce uremic symptoms; thereafter, albeit controversial, evidences suggested that dietary protein restriction can also slow the rate of progression of renal failure and the time until end-stage renal disease. This reviews focuses on the dietary factors and their influence on the loss of renal function and on the evidences in the literature supporting a nephroprotective role of the low-protein diet.