What happens if your body doesn't intake enough calories? Say, if you were drinking green tea all day in substitute of yours meals, you would be getting fuller, but a cup of tea only contains 2 calories. What would happen

Your body would go into starvation mode ... Holding onto fat as long as possible, and burning muscle mass instead.

You would lose weight depending on your current size and level of activity. If you continue to do so until you body spends 3,000 calories, that would be equal to 1 pound.

Your body would think its starving and not know when it's gonna get food again so it would kick into survival mode and hoard every single 2 calories you ate.

You would go through about 3 days of total hell . . . There are "Juicers" who go totally with drinking the juice of vegetables, and they try first for 10 days. They say the first 3 - 4 days of extreme calorie deficit is extremely hard . . . Most will take a week off from work just to try and get through it . . . . You body is pushed to using fat reserves to keep it going but it takes a bit for that to happen . . .Just eat healthier and in moderation . . No need to starve yourself.

Weight lost this way will come back VERY quick.

it's not normal!

You will start losing weight because your body will use
stored fat to produce the energy it needs. However, it will soon go in survival
mode and you will lack the essential nutrients you need. If you are considering
doing this to lose weight, it is better to eat healthy, reduce the portions you
consume and to exercise.