Eight 8-oz glasses of water a day is an accidental recommendation. Dr. Heinz Valtin pointed out the error. The Food & Nutrition Board in the 1940s recommended ‘one milliliter water per calorie of food.’ A 1,900 calorie diet would indeed yield 64-oz per day. But…..the next recommendation was forgotten: “Most of this quantity is contained in prepared foods.” That’s right, you can replace most of your daily water loss with food!