Arising from: Fouque D and Aparicio M (2007) Eleven reasons to control the protein intake of patients with chronic kidney disease. Nat Clin Pract Nephrol 3: 383–392 doi:10.1038/ncpneph0524

I appreciate the intense review of the impact of protein in experimental models of chronic renal disease; however, if we are to use best clinical evidence to care for patients with chronic kidney disease (CKD), how can we ignore the Modification of Diet in Renal Disease (MDRD) study? This NIH, randomized double-blind study clearly showed that lowering protein intake did not have an important effect on glomerular filtration rate or patient survival. This is important for two clinical reasons. First, to restrict dietary protein intake means we must emphasize either intake of fat or of carbohydrate. As people with CKD die of cardiovascular disease and not renal failure, encouraging consumption of foods that enhance atherogenesis does not seem logical. Second, patients with CKD are asked to make many difficult lifestyle changes, including restricting their intake of salt, potassium, calories and fluid, exercising, losing weight, and taking multiple medications that are known to have beneficial effects (e.g. antihypertensives, lipid-lowering drugs and agents that suppress the renin–angiotensin–aldosterone system). It seems logical to focus on the most important interventions, which evidence-based medicine would suggest is not reducing protein intake, but the other issues listed above.