Does a High-Protein Diet Affect Kidney Function?

Despite a controversial belief otherwise, new evidence suggests that diets high in protein do not adversely affect kidney function in healthy adults.

To examine this association, the researchers conducted a systematic review and meta-analysis of trials that compared higher-protein (HP) diets (≥1.5 g/kg body weight or ≥20% energy intake or ≥100 g protein/d) with normal- or lower-protein (NLP; ≥5% less energy intake from protein/d compared with HP group) diets on kidney function.

Overall, the review included 28 articles with data from 1358 participants. They used random-effects meta-analysis, meta-regression, and dose-response analysis, and conducted analyses of postintervention (post) glomerular filtration rate (GFR) and change in GFR from preintervention to post.

In the post-only comparison, the researchers observed a “trivial effect” for GFR to be higher after HP intake (standardized mean difference [SMD]: 0.19), and the change in GFR did not differ between interventions (SMD: 0.11).

In the post-only comparison, they also observed a linear relation between protein intake and GFR (r = 0.332), but not between protein intake and change in GFR (4 = 0.184).

“Postintervention GFR comparisons indicate that HP diets result in higher GFRs; however, when changes in GFR were compared, dietary protein had no effect. Our analysis indicates that HP intakes do not adversely influence kidney function on GFR in healthy adults.”

—Michael Potts

Reference:

Devries MC, Sithamparapillai A, Brimble KS, et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis. The Journal of Nutrition. 2018. 148;11(1):1760–1775,