TABLE 3.

Summary of findings from the GRADE assessment of studies included in the meta-analysis of whether higher-protein intakes affect kidney function in healthy people¹

	Anticipated absolute effects2
Outcomes	Risk with low protein	Risk with high protein, SMD (95% CI)	Participants, n (studies, n)	Quality of the evidence (GRADE)3
Pre/post change	—	0.11 higher (−0.05 lower to 0.27 higher)	1547 (19 RCTs)	⊕ ◯ ◯ ◯Very low4,5
Post-GFR	—	0.19 higher (0.07 higher to 0.32 higher)	1688 (31 RCTs)	⊕ ⊕ ◯ ◯Low4

¹GFR, glomerular filtration rate; GRADE, Grades of Recommendation, Assessment, Development, and Evaluation; RCT, randomized controlled trial; SMD, standardized mean difference.

²The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

³GRADE Working Group grades of evidence are as follows—high quality: we are very confident that the true effect lies close to that of the estimate of the effect; moderate quality: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different; low quality: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect; very low quality: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

⁴Most studies had serious issues of reporting and were classified as unclear for the domains of random-sequence generation and allocation concealment.

⁵Unexplained heterogeneity (P = 0.02, I² = 44%). The 95% CI includes a negligible reduction, no difference, and a moderate increase in GFR (−0.05 to 0.27).