Turning to traditional Chinese medicine and a Taoist concept of health and long life, one is taught to be moderate in every action and attentive to the signals of the body, and to the prevailing influences of nature. Eating when hungry and drinking when thirsty, we should ingest only enough food and drink to satisfy actual needs, needs which match our level of activity. Advice regarding water intake is to drink only when thirsty or to drink a few sips regularly throughout the day. To consume more than what is essential is considered in defiance of natural balance.
There are obvious cases where higher fluid consumption is important, such as for people who are perspiring profusely [due to exercise, hot weather, or resulting from a feverish disease], those who are losing fluids due to diarrhea, as well as one who tends to form kidney stones. But by eating the suggested five servings of fruit per day, plentiful amounts of water are provided; many fruits and vegetables being more than 80% water in content.
Most yin quality foods in a healthy diet contain a significant quantity of water making it feasible to get the 2.5 liters a day without drinking copious amounts of water. However, the popular impression is that for good health one must drink 2.5 liters of water per day, when essentially, emphasis needs to be placed upon consuming fresh fruits and vegetables, not on high volume water-intake. Health advisories recommend that sedentary women consume approximately 2,000 calories per day, for which the suggested 1 ml/calorie translates to only 2.0 liters of total water needed. Adding 1.9 liters of water from drinking glass after glass of water simply doubles such suggested intake.
Drinking large volumes of water appears to be inconsistent with age-old advice regarding health maintenance.