All of the above-water is lost through prespiration, urine and when we breath. on average, an adult loses about 2liters of water everyday through normal body processes. thus, a personns body could become dehydrated without water. however, a persons exact water requirements depends on what they consume (diet), whether their healthy, sick on special diets (state of health), what they do i.e. construction worker, baseball player (level of activity)and where they are i.e. dry dessert area, humid surroundings (environment).