Here are some facts and figures that I've learnt about water along the way. I apologise in advance for the geekiness, I'm a teacher, can't help it!
So why is water important?
* The brain is 70% water
* Our lungs are 90% water
* The human body is 66% water
* Blood is 82% water
So what does water do?
* Water is the primary lubricant in the joint spaces and prevents arthritis and back pain.
* Water helps immune system to function optimally
* Water keeps arteries and brain from clogging, reducing heart attacks and strokes.
* Water is related to brain function and is required for producing neurotransmitters, including serotonin; is necessary for manufacturing hormones needed by the brain, such as melatonin; Attention Deficit Disorder (ADD) can be prevented with adequate water intake as well as improve attention span.
* Water aids in the prevention of loss of memory due aging.
* Water decreases signs of aging, causing the skin to appear smoother.
* It cleanses the insides of your body
In terms of weight loss, water has a big role to play too! If we don't drink enough water, our bodies can't metabolise the fat properly and we'll also retain water. You know that survival mode when you're under 1200 calories? Happens with water too! So when you're not drinking enough the body goes geeeeeze I dunno when I'll get my next fix of water so grabs all the water it can and doesn't let it go! So it's holding on to water, meaning that you're gaining water weight and seeing smaller losses on the scales.
The kidneys don't work properly if they don't get enough water so the liver has to pick up some of the slack, but then it's not got enough time and energy to do it's own job properly, which is to convert stored fat to energy. So if you want the liver free to convert as much fat to energy as possible, which'll help your losses, you need to feed your kidneys with plenty of water! The NHS/Dept of Health recommend 1.2 litres of water a day, on top of everything that you get in food. So like Ricki said, because we don't get as much water from food because of the diet we do, you need to try and drink more to make up for it. Someone told me that the recommended 2.5-3 litres includes what you use in shakes/soups/meals but I'm not 100% sure of that so still aim to drink as much as I can on top of that.