The need to drink glass after glass of water is simple: Healthy people, living in a temperate climate leading sedentary lifestyles do not need to run around and drink bottle after bottle of water to satisfy the "8 x 8 rule" (eight oz. of water eight times a day) which has no basis in fact. The following is an extensive review of this issue:
No issue has caused moreindividualsstruggling to lose weight more anxiety than the “need” to drink bottle after bottle of water. The lay press is overflowing with the fact that water is need for "organ function,” quoting the fact that more than 70% of the body is made up of water. The claims that drinking 8 glasses of water a day is needed to flush “toxins” and other dangerous “poisons” from the body, for skintone, to prevent constipation, cancer, heart disease, and fatigue fill thousands of web pages.Weight loss, prevention of headaches, digestion, circulation, nutrient absorption and temperature regulation and a hundred more assertions often make the dieter feel guilty that he is not drinking his water.
Indviduals trying to lose weight have enough to remember and watch. Energy and time should not be wasted on the useless need to extra drink water. Here is why:
Scientific Basis of Conclusions: These conclusions are based on a recent study from the University of Pennsylvania by Dr. Dan Negoianu and Stanley Goldfarb in June 2008 and by a very extensive review of essentially the world’s medical literature by Dr. Heinz Vatin from the Dartmouth MedicalSchool published in 2002. Dr. Vatin was requested to review the scientific evidence for the need to consume extra water by the American Physiological Society which published the evidence in the American Journal of Physiology Regulatory, Integrative and Comparative Physiology. His conclusions are based on reviewing over 100 medical studies in the world's literture. Read them yourself!
Quote from Dr. Vatin’s report: “No scientific studies were found in supportof 8 × 8. (8 oz. of water 8 times a day. Rather, surveys of food and fluid intake on thousandsof adults of both genders, analyses of which have been publishedin peer-reviewed journals, strongly suggest that such large amountsare not needed because the surveyed persons were presumably healthyand certainly not overtly ill. This conclusion is supported bypublished studies showing that caffeinated drinks (and, to a lesserextent, mild alcoholic beverages like beer in moderation) mayindeed be counted toward the daily total, as well as by the largebody of published experiments that attest to the precision andeffectiveness of the osmoregulatory system for maintaining waterbalance. It is to be emphasized that the conclusion is limitedto healthy adults in a temperate climate leading a largely sedentaryexistence, precisely the population and conditions that the "atleast" in 8 × 8 refers to. Equally to be emphasized, lest themessage of this review be misconstrued, is the fact (based onpublished evidence) that large intakes of fluid, equal to andgreater than 8 × 8, are advisable for the treatment or preventionof some diseases and certainly are called for under special circumstances,such as vigorous work and exercise, especially in hot climates.”
Dr Vatin concludes: “Since it is difficult or impossible to prove a negativeinstance, the absence of scientific literature supporting the8 × 8 recommendation,the author invites” communications”
No substantial evidence has been submitted to a peer reviewed scientific journal to date.
Further Doubts? If the reader has further doubts, it’s very easy to review Dr. Vatin’s review article which is written in a very readable manner. Just click REVIEW Dr. VATIN’S ORIGINAL ARTICLE.
How Did Dr Vatin Draw His Conclusions?
Dr Vatin’s made great effort to include as much data as possible. Here is his review of how he came to his conclusions:
Dr Vatin communicated with the following scientists after finding no proof in the written medical literature of any benefit from drinking water for the “average” person as quoted above.
“In the absence of scientific articles, personal contacts with nutritionists turned out to be the best resource. Having conductedsimilar searches in vain, these nutritionists were frustratedby the perpetuation of 8 × 8 and offered tremendous help freely.They were Dr. Abby G. Ershow (Nutrition Program Officer, NationalHeart Lung Blood Institute, NIH), Dr. Ann C. Grandjean (ExecutiveDirector, Center for Human Nutrition, University of Nebraska MedicalCenter), Dr. Barbara J. Rolls (Guthrie Chair, Department of Nutrition,Pennsylvania State University), Dr. Elizabeth M. Whelan (President,American Council on Science and Health), Dr. Allison A. Yates(Director, Food and Nutrition Board, National Academy of Sciences),and Dr. Paula R. Trumbo (Senior Program Officer, Food and NutritionBoard, National Academy ofSciences).”
Colleagues
Personal inquiries with ~15 colleagues who specialize in the area of water balance resulted in prompt responses. None of themknew the origin neither of 8 × 8 nor (with one possible exception) ofpublished articles that support the claim. The possible exceptionwas Dr. Lise Bankir, whose views have been described under POSSIBLEBENEFITS OF A HIGH WATER INTAKE: Speculative Advantages. Becausenaming these colleagues might draw them into the controversy over8 × 8 without their permission, I will not list them here; however,they know who they are and I thank them for theirefforts.
Authors of Lay Articles
I received no replies from three authors of lay articles whom I had asked for the sources and scientific evidence for theirassertions andrecommendations.”
Here are the scienfitic articles Dr Ventin used in his analysis.
BULL OR NO BULL? 
