With interest we read the systematic review and meta-analysis by Morris et al.1 which concluded that dietary potassium (K+) restriction in patients with chronic kidney disease (CKD) is associated with a 0.22 mEq/L decrease in serum K+ and 40% lower mortality hazard, but not with progression of CKD. However, we would like to raise 2 points of concern, including (1) a discrepancy between the results of the meta-analyses and the original studies and (2) an overestimation of the effect of dietary K+ restriction on serum K+.