Re: Net water balance from cola -- diuretic efficiency

A search of the medical literature revealed 2 articles on caffeine and 
calculating "water balance."  In one of those, subjects did not consume any 
caffeine or related substances for 5 days and then were given 6 cups of 
coffee containing 642 mg of caffeine.  They had an average negative water 
balance of 753 +/- 532 ml over the next 24 hours. (Neuhauser-Berthold, 
Beine S, Verwied SC, Luhrmann PM. Coffee consumption and total body water 
homeostasis as measured by fluid balance and bioelectrical impedance 
analysis. Ann Nutr Metab 1997;41(1):29-36).  In the other article, the 
authors used figures of 1.17 ml water lost/mg caffeine consumed and 
10 ml water lost/ g alcohol in calculating water balance (Stookey JD. The 
diuretic effects of alcohol and caffeine and total water intake            
misclassification. Eur J Epidemiol 1999 Feb;15(2):181-8).  I am not sure of 
the derivation of these numbers, although the number for caffeine is the 
same as that of the Neuhauser-Berthold et al. article.  I could not find 
any reference to the caffeine content of different beverages having 
different effects; it appears to be a function of the amount of caffeine 
present and not the source of the caffeine.  Similarly, with alcohol, the 
effect seems to be a function of the amount of alcohol consumed and not the 
source of the alcohol. 
                                                                   

                       
 
                                                                   

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