The advice to drink at least eight glasses of water a day can be found throughout the popular press. One origin may be a 1945 recommendation that stated: A suitable daily allowance of water for adults is 2.5 liters. Most of this quantity is contained in prepared foods. If the last, crucial sentence is ignored, the statement could be interpreted as instruction to drink eight glasses of water a day.
Furthermore, existing studies suggest that adequate fluid intake is usually met through typical daily consumption of juice, milk, and even caffeinated drinks.w9 In contrast, drinking excess amounts of water can be dangerous, resulting in water intoxication, hyponatraemia, and even death.
FICTION!