The claim that 8 glasses of water is “essential” is false, but the point of drinking a high amount of water is crucial to hydration and a human’s well-being. The claim cites the Mayo Clinic’s article “Water: How much should you drink every day?” which does give some great insight into logistics of water consumption for humans like “The U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is:
- About 15.5 cups (3.7 liters) of fluids a day for men
- About 11.5 cups (2.7 liters) of fluids a day for women”
While these points are helpful for understanding how important drinking more water than you think you should per day, nowhere in the article says that drinking 8 glasses of water is “essential for hydration”. The title of the claim very much aligns with the article’s overall thoughts, but the title is still misleading. I would make the claim out to be that 8 glasses of water is the preferred amount of water for humans to drink in a day, because the original claims use of the word "essential" means that you need to drink 8 glasses of water to be hydrated, which is not a claim that the Mayo Clinic's article ever says.
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256