In regard to the first comment, thank you for your in depth response. You make a very good point about the water replacement theory through food consumption only. We are very fortunate in this country to have access to clean, pure water, but I disagree that food alone is enough to fulfill all of the body’s metabolic requirements. “Food” can mean many different things to many different people. I don’t think I am over exaggerating when I say that the average American diet does not include the amount of fruits and vegetables high in water content that is necessary for the body’s water needs. Having food heavy in carbohydrates or dry foods such as a bag of chips or pastas are common, but require water to break down for digestion. For those of us that are health conscious and looking to get water from food sources only, I would say, proceed with caution, and monitor your urine.

Here is some more information about coffee and tea vs. water consumption. A cup of coffee has about 200mg of caffeine. A cup of tea has quite a bit less (40-100mg), depending on the strength of the tea. (I pulled these numbers from the Tea Council and Association of the US.) However, the general consensus as of late is that, despite the caffeine, these beverages still count towards your fluid intake for the day. The reason is that, although caffeine is a diuretic, the amount in a strong cup of coffee or tea is not enough to dehydrate, and there will still be a net gain of fluid. I still want to emphasize the fact that for the best hydration for your body, choose fluids that do not contain caffeine. It is my bias to say this, however, I am definitely guilty of consuming my share of caffeinated beverages.

Although coffee and tea may be equal in their hydration factor, tea still gets the upper hand for your health. A recent sutdy in the European Journal of Clinical Nutrition says that drinking tea is not only as good as drinking water, but possibly better, as it may carry extra health benefits in protecting against heart disease and some cancers. We can also look to other cultures where they do not enjoy the luxury of purified water, where they do drink tea in place of water.

Drinks with caffeine can be good to suppress appetite and help with snacking urges. Having an afternoon or evening cup of tea/coffee is calorie free (as long as you don’t add anything to your cup). Green or herbal teas are a great choice because of the extra health benefits.

In writing this article I did not really want to get carried away with talking about when exactly to be consuming your fluids in regard to eating. There is a lot of debate over this topic as well, as some people think that drinking water during or with meals can dilute stomach acids and slow digestion. In cohesion with this thought, researchers have begun to recommend drinking fluids 1-2 hours after eating solid foods to avoid making your stomach a “water balloon.” (This is useful to make you feel full, especially if you are looking to lose weight.)

Keep the comments coming!

I’m no expert, but my understanding is that water requirements are largely derived from loss-replacement studies and tend to be misunderstood. As it turns out, a significant portion of water intake happens (or at least should happen) through food; depending where the loss-replacement data is coming from, it may be that it was never intended that people actually drink that much, just that their total moisture intake should roughly equal that amount – for the “average person” – in “average conditions.” Maybe we don’t need to drink as much as the new-school fitness experts are often saying?

Makes sense – as you point out, the water molecule is ubiquitous at the cellular level in all living organisms. After all, what we eat is (or used to be) alive. Not too jazzed about the drinking loads and loads of water thing – in a diet that includes lots of fresh fruits and veggies, that kind of thing shouldn’t be necessary unless you marathon in Mojave.

I liked that you mentioned that water intake depends on lots of variables, for example the temperature/humidity (not just because of perspiration; loss can also occur via evaporation from skin and especially mucous membranes if I remember correctly). It also depends on body mass – a variable that is often but not always mistakenly misinterpreted as a gender difference in the nutrition field. In my opinion, the body mass thing is also behind old people not drinking as much water; as with other nutrients, they simply need less because they are actually growing smaller as they age. I’m no expert, but old peoples’ kidneys might not be up to filtering the gargantuan amounts of beverages that young sporty-types consume these days from their very large Nalgene bottles.

All that said, the kind of American diet based on lots of dry grains (breads, chips, crackers, cookies, bagels, etc., etc.) is of course not going to cut it in terms of water intake. I really like your advice to check pee color; it is a cheap (and gross) but pretty effective way to get a customized assessment of water intake, and though not foolproof, is much better advice than the typical rule-of-thumb liter requirements – which, again, are based on loss-replacement studies taking into account body mass.

I’ve often heard from exercise and nutrition specialists to “not wait until you’re thirsty” to drink. It never made much sense to me – I can’t believe that somehow it’s better to trust overconsumption over one’s own biological thirst mechanism whose very nature is to prevent you from becoming dangerously dehydrated. This advice has the spirit of “better safe than sorry,” which I guess is fine – my problem is that overconsumption of nutrients is consistently advocated by exercise and nutrition specialists, from water to vitamins to just about anything. While thinkers of the day are quick to blame the U.S.’s obesity issue on things like fast food proliferation or a declining food quality due to agricultural centralization/simplification, perhaps the issue stems partially from the fact that our experts are always telling us to eat and drink more than we need. Definitely not saying that water is making anyone fat – just bringing up the point that balance, moderation, and common sense so often lose out over trends, miracle solutions, and “better-safe-than-sorry,” and that this is sort of a philosophical thing that perhaps expert types might consider with fruitful result.

From a losing weight perspective, water has some importance I think. I vaguely recall water being a catalyst/ingredient in beta-oxidation; doesn’t hurt to have around for eliminating the resulting acetone that’ll be floating around the place, either. Some weight loss advice is voodoo; actually, I don’t knock that, because some voodoo seems to actually work. Water is one of those things that doesn’t seem to hurt much as long as you don’t totally overdo it, so even though I think that overconsumption of water is weird advice for people happy with their weight and diet, it might be great advice for people looking to lose weight or alter their diet. For that reason, I think the article was a great one to include in the blog. It seems to have some potential perhaps for being a weight loss tool in keeping with the site mission.

One last contention is that clean freshwater is neither cheap nor easy to get from a global perspective. I’m no expert, but my guess is that percentage-wise, most unprepped earth water fit for human intake is trapped either in the cellular structure of food or trapped inside giant blocks of ice at the poles. Nice clean water is actually a bit of a luxury from what I understand, and I’m very grateful we have it here in the U.S. in ample amounts; might not always be the case.

Keep the interesting articles coming! Any chance for citations in future articles?

PS please forgive the length – I know the site founder from HS and promised I’d leave a thoughtful post to contribute to discussion on the site. PSS glad you didn’t mention bisphenol-A