How many pounds can you lose without eating or drinking water for seven days?
It's impossible. Forget it. After 7 days, eating a little food will make you fat. If you only drink water for 7 days and lose 10 kg, then on the eighth day, you will gain 2 kg after eating for one day. The slower the rebound, the fatter it is. Moreover, if you start eating when you are hungry, you will only rebound faster.