Why Do We Need To Pee So Much When We’re Fasting?
So, on average, water makes up about 60-70% of the human body, largely depending on your age. Our bodies lose water through our urine, sweat, faeces and breath, so we have to continually replace this by drinking and eating (around a third of the water we consume comes from our food). If we don’t do this, our bodies can become dehydrated.
Article source: https://www.huffingtonpost.co.uk/entry/why-do-we-pee-a-lot-when-were-fasting-were-not-drinking-anything_uk_6255812ee4b0e97a351726da