Water is important whether you are losing weight or not. The human body consists of anywhere between 55-78% water. The functions of water in human body are vital.
Water:
Transports nutrients and oxygen into cells
Moisturizes the air in lungs
Helps with metabolism
Protects our vital organ
Helps our organs to absorb nutrients better
Regulates body temperature
Detoxifies
Protects and moisturizes our joints
Here's a helpful quote from a related article:
"Without the right amount of water, a person cannot absorb food properly. People who eat great, healthy food but never touch a bottle of water are still not working up to par as the body cannot flush out the waste product produced from food. This leads to many kinds of health conditions that could be avoided by just drinking water regularly. Illnesses that are produced from being overweight are a prime example of this." (
http://drinkingwaterweightloss.com/)