Nutrition
Clear, carefully sourced guides to everyday questions about food and drink. Start with hydration: what counts, how needs vary, and what a reference value really means.
HYDRATION / START HERE
HYDRATION / FEATURED GUIDEA clearer way to think about water
Total water includes food and beverages. These guides explain the evidence without prescribing one number for everyone.
How Much Water Should You Drink a Day?
A clear guide to total water, beverages, food, and the limits of a daily reference value.
HYDRATION / EXPLORE THE COLLECTION
Go beyond a glass count
Question eight glasses
See why a memorable daily rule does not describe every person's water needs.
Count food and drinks
Learn how coffee, tea, sparkling water, milk, and water-rich food contribute.
Explore the calculator
View National Academies total-water reference values and their limits.
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