Essay: Debunking the 8-Glasses-a-Day Myth: Scientific Evaluation and Skin Clarity

Many of you have likely heard the recommendation to drink eight glasses of water every day. According to some sources (e.g., this article from Food and Supply Source), drinking eight glasses of water daily will increase muscle stamina, improve kidney function, clear skin, boost brain function, and provide many other benefits compared to drinking only when thirsty. It seems that the original source of the eight-glasses-per-day claim is a 1945 statement from the U.S. Food and Nutrition Board, which recommended 2.5 litres of daily water intake. The Board’s recommendation was not based on any research. It turns out that the popular recommendation to drink eight glasses of water daily is not based on any scientific evidence! For an entertaining take on this question of optimal hydration, watch this Adam Ruins Everything clip. For the Question of the Week, describe how the eight-glasses-per-day claim could be tested scientifically. Focus specifically on the claim that drinking eight glasses of water per day will lead to clearer skin compared to drinking only when thirsty. In your response, please address the following: (a) State a hypothesis. (b) Design an experiment to test the hypothesis (maximum 4 sentences). (c) State your prediction. (d) Suppose that you run the experiment and find that your prediction was correct. Does this prove that the hypothesis is true? Why or why not?