We have all heard of that standard rule of thumb “drink at least eight 8-oz glasses of water a day.” This standard rule originated in 1945 from a Food and Nutrition Board report that recommended we drink 1 millimeter of water for every calorie we consume. Based on a 2,000-calorie diet, that comes out to be about eight 8-oz glasses of water a day. The interesting thing about this, is that current research has found no evidence supporting this notion, not to mention that the amount of water you need depends on a number of other variables such as the weather, elevation, your activity level, etc. Though we may not need eight glasses a day, water is still essential for our bodies to function properly. So what counts as water and how do you know if you are getting enough?
Well, If are anything like me, the first beverage you go for in the morning is a cup of coffee or strong tea. Since it is winter, the rest of the day I tend to stick to hot tea or more coffee (sometimes caffeinated, sometimes not). I have found that this time of year, I only drink plain water during or right after a workout. I have always been told that caffeine is a diuretic so I started thinking, I am drinking all this liquid but am I really staying hydrated?
To answer these questions I did a little research. I found a study published by the British Journal of Nutrition that conducted an experiment to test the effects of black tea on hydration status. The study consisted of 21 males taken from the general population. In the study, the subjects were observed for a 12- hour intervention period where all food, drink and physical activity was controlled. Blood was sampled at 0,1,2,4,8, and 12 hours and 24 urine sample was taken (Ruxton, and Hart 1-8). The subjects were put through an experimental study (given black tea) and a controlled study (given identical amounts of boiled water). The results revealed no significant difference between the blood or urine measurements, concluding that the black tea, in the amounts studied offered similar hydrating properties to water (Ruxton, and Hart 1-8).
So the good news about this, is you can stay warm and hydrated drinking your hot tea or coffee this winter. If you are still concerned that you are not getting enough water in your diet don’t forget that foods such as soup, fruits and vegetables also contain a lot of water and count as part of your daily fluid intake. But if you’re still concerned you are not getting enough water, here are a few symptoms of dehydration and ways to check your hydration status.
Symptoms of dehydration:
- Cravings for sugar or salt
- Dry mouth
- Dark urine
- One of the best ways to monitor hydration is through urine. If you are staying adequately hydrated your urine will be “very pale yellow”, “pale yellow”, or “straw colored”.
- Another good way to check is to pinch the back of your hand while it is resting on a flat surface. When you release the skin, it should snap back into place. If it is slow to go back then chances are you are dehydrated.
- Ruxton, Carrie , and Valerie Hart. “Black tea is not significantly different from water in the maintenance of normal hydration in human subjects: results from a randomized controlled trial .” British Journal of Nutrition. (2011): 1-8. Web. 5 Jan. 2013.