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.