text: what is the minimum water required daily for the body to function? not meaning that 8 glasses of water crud, i am talking the minimum amount needed to survive. the body is unable to store water for any length of time and needs fresh supplies every day due to losses from lungs and skin, accounting for 50% of water loss; losses from urine and faeces account for the rest of the total losses. the amount we need depends on our metabolism, the weather, the food we eat and our activity levels. heavy or obese people carry less body water than people of a healthy weight. as fat content increases, lean tissue decreases, leading to an overall decline in total body water. body water is higher in men than in women and falls in both with age. most mature adults lose about 2.5 litres (women) to 3 litres (men) per day and the elderly lose about 2 litres per day. this water loss needs to be replaced through food and beverages. foods provide about 1 litre of fluid and the remainder must be obtained from beverages.