Water intake

Measurable dehydration degrades physical and cognitive performance, and that part of the evidence is solid. The familiar instruction to drink a fixed number of glasses a day was never derived from trials; requirements vary with body size, climate, diet and activity, and food contributes a meaningful share. Drinking far beyond thirst carries its own risk, including dangerously low blood sodium.

Reviewed 2026-09-20

Official sources

How this list was built

We searched Europe PMC for English-language papers published since 2012 whose title contains “water intake” or “water consumption” or “hypohydration” or “drinking water intake”, kept meta-analyses, systematic reviews, trials and observational studies, because a diet or exposure like this cannot be randomised for long and its outcome evidence lives in cohorts, then ranked them by study design first, then recency and citations. Retracted papers are removed.

Open a paper to read its abstract and ask for an AI brief of what it found.