I’ve been confronted with this one many times in the past, but it was not until recently that I discovered the truth, in all of its life altering magnitude. Although there is little to state that drinking this much water every day has any detrimental effects, failing to do so is unproven to cause any direct harm either. For many years it was considered fact, widely due to a 1945 study by the Health and Nutrition Board which declared it necessary to consume 1 millimetre of water per single calorie of food, the recommended 1,900 calories equating to some 64 ounces (approx. 8 average size glasses) per day. Turns out they forgot to include the water consumed as content in food in their calculations- rendering their research inaccurate.