But … The science!

From Jewish World Review 

“We've all heard the age-old advice to drink eight cups of water a day. But if you fall short, don't worry: That advice is probably wrong anyway.

…

“The advice to drink eight cups of water a day stems from a 1945 recommendation from the Food and Nutrition Board of the National Research Council, which encouraged adults to consume about 64 ounces of water daily. The recommendation referred to a person's total daily intake of water, including from all their foods and beverages, but it was widely misinterpreted to mean that people should drink eight 8-ounce glasses of water every day.”

https://jewishworldreview.com/1222/8_cups_of_water.php3

“The science” depends on what a reader wants to read in any study. Facts can be slippery. Or, only a matter of opinion.