Back to the future: restricted protein intake for conservative management of CKD, triple goals of renoprotection, uremia mitigation, and nutritional health

Lowering dietary protein intake (DPI) to approximately 0.6–0.8 g/kgBW/day may be renoprotective through various mechanisms, and it has been recommended in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) as a means to also control various metabolic consequences of advanced CKD, such as uremic symptoms, hyperparathyroidism, hypertension, hyperkalemia, and hyperphosphatemia. A meta-analysis in this issue of the Journal suggests that low-protein diet is effective and safe when used to retard progression of CKD and alleviate uremic complications. A potential deleterious consequence of lowering DPI in this population is the development or worsening of protein–energy wasting (PEW), which can contribute to poor clinical outcomes such as higher mortality and morbidity. There is currently insufficient high-level evidence to determine the ideal level of DPI in patients with NDD-CKD with high risk of PEW. For the time being we recommend a DPI of 0.6–0.8 g/kgBW/day, and increasing this as needed on an individual basis in patients with PEW. Further examination of this dilemma in randomized controlled clinical trials will be necessary.