Findings from the meta-analysis on total water intake and all-cause mortality:
Six cohort studies investigated the association between total water intake and risk of all-cause mortality[5, 6, 14-16, 19]. These studies included a total of 115815 participants, among them 14250 deaths occurred. The summary effect size for all-cause mortality comparing the highest and lowest intakes of total water was 0.95(95% CI: 0.83-1.09, P=0.47), indicating no clear significant association between total water intake and risk of all-cause mortality (Figure 2 ). However, significant between-study heterogeneity was seen (I2 = 66%; P=0.002).