Question

why doctor advise us drink 2 liters water daily

Answer 1

the doctor advise us because a food need water as it help kn digestion .

Answer 2

Water cushions our joints, keeps our eyes and mouth moist, helps us swallow, allows us to absorb nutrients, and helps get rid of waste. On top of that it helps regulate our temperature.
So we should drink at least 2 liters of water daily.