Objective:

To evaluate the health benefits associated with increased daily water intake through a systematic review of randomized clinical trials.

Approach:

• Systematic Review: Analysis of 18 randomized clinical trials with intervention durations ranging from 4 days to 5 years.

Key Findings:

• Adults with overweight or obesity consuming approximately 500 mL of water before meals achieved 44% to 100% greater weight loss compared to control groups over 12 weeks to 12 months.
• A trial involving adolescents showed no significant effect on weight (effect size, -0.0; P = .88).
• Increasing water intake to achieve 2000 mL daily urine volume resulted in significantly lower kidney stone recurrence rates (12 of 99 vs 27 of 100; P = .008).
• Increased water intake of 1500 mL daily improved quality of life scores in patients with recurrent headaches (4.5 points; P = .007), though reduction in headache days was not statistically significant.
• For premenopausal women with recurrent urinary tract infections, increasing water intake by 1500 mL was associated with fewer infection episodes (1.5; P < .001).
• In patients with type 2 diabetes, a premeal water intervention totaling 1000 mL daily led to decreased fasting blood glucose (-32.6 mg/dL vs +5.3 mg/dL in control; P = .003).
• 10 of the included trials (55%) reported at least one positive result, while 8 (44%) reported negative results.

Interpretation:

Limitations:

• Limited quantity and quality of evidence across the studies.
• Variability in intervention durations and populations studied.

Conclusion:

Sources:

• JAMA Network Open