Water is a combination of hydrogen and oxygen; it is the basis for the fluids of the body.

Water makes up more than two thirds of the weight of the human body. Without water, humans would die in a few days. All the cell and organ functions depend on water for functioning. It serves as a lubricant and forms the base for saliva and the fluids that surround the joints. Water regulates the body temperature, as the cooling and heating is distributed through perspiration. Water helps to alleviate constipation by moving food through the intestinal tract and thereby eliminating waste.

Water is obtained from some of the foods we eat. These are foods that are 85 to 95% water. Some water is obtained from the by-products of metabolism. But our main source of water is our drinking water, which is the best source. Water is also obtained from soup, milk, and juices. Alcoholic beverages and beverages with caffeine (such as coffee, tea, and colas) are not the best choices because they have a diuretic (water-excreting) effect.