I haven't researched this myself, but I recently watched a TV program that was talking about water intake, and how it is recommended to drink about 2L, however the program went on to discuss how the scientists who first stated this mentioned that nearly all that water comes from food.
Drinking plenty of water (as part of a hydration experiment) was not in any way beneficial compared to the control subject.
Personally I would drink at least 4.5L a day, and as I exercise regularly I am under the impression it is vital to consume extra water, However I have recently cut back to about 2L and not noticed any difference, except less trips to the loo.
I just take smaller mouthfuls now rather than necking back 2 or 3 larger ones a time.
well something must be missing here because what they described just doesn't make any sense.
some animals can get all of their water needs from food but they have specialized kidneys/excretory systems that can handle extremely concentrated urine
some water is generated as part of respiration but think of all the water you would sweat off, is expelled in your breath, etc.
just doesn't make any sense
I found an interesting wikipedia entry, but I don't know how accurate it is.
20% of water intake comes from food. Now bear in mind I am bulking and probably eat lots more than the average person, and good nutritious food too, chicken, rice, lamb, beef, nuts, fruit, milk, whey, peanut butter, oats, wheat etc etc. I'm sure these have a much higher water content than say, a Danish pastry or a Mc Donalds quarter pounder but I wouldn't know, it's just a guess. (Forgive me for generalising)