A reader recently left this comment: I have never understood that whole “caffeinated beverages don’t count towards your water intake” business. Would you please explain that perhaps in a separate post?
I know caffeine is a dieuretic so you eliminate more than you take in, but you are still taking in liquid. To me “doesn’t count” means you would be in the same health situation at the end of the day if you drank 8 glasses of tea or drank zero glasses of anything, and that just can’t be.
Please help me understand why caffeinated beverages don’t count toward your water intake.
In an effort to answer her question properly, I did some online searching and found that opinions vary widely. The best article I found was from UK’s The Daily Mail. Britain’s leading nutritionist, Jane Clarke recommends 2.5 liters of water a day because:
We know from research that this is what the body needs to function properly (from helping the brain to work at its optimum, to eliminating waste). If you drink enough your energy levels will be more consistent (say goodbye to that after-lunch snooziness or end-of-the-day crabbiness); many of the people who ask me for advice also find that their concentration improves.
Clarke also believes that it’s fine to count tea and coffee as part of your daily intake, with a few cautions:
The good news is that you can now count tea and coffee as part of your intake. Previously it was thought they acted like diuretics, encouraging the body to get rid of fluid. We now know this isn’t true, and you can drink tea and coffee as part of your 2.5 litres. And there is nothing like a cup of tea to give you a lift.
My only note of caution is that large amounts of caffeine can reduce the amount of calcium we absorb from our food; the tannins in tea have a similarly negative effect on iron absorption.
Also, caffeine, even small amounts, can make sensitive people feel more stressed, jittery, and can keep you awake if drunk at the wrong time of day. A couple of cups a day are fine as part of your water intake.
One of the main reasons I’m choosing water over other sources of liquid is the fact that water contains ZERO calories, and I’m trying to lose weight. This Web MD article explains how Liquid Calories Add Up Quickly.