I read somewhere that the process of chewing, swallowing and digesting sticks of celery actually uses up more calories than the sticks of celery contain. Therefore you actually lose weight when you eat it and it takes the edge off your appetite.
Ice water does the same. It takes some amount of energy to warm up the water and move it along, but the water adds 0 cals, so you lose calories by drinking ice water.
The same arguement could be made for celery.
3500 calories is what it takes to support one pound of body fat.
You could spend the time chewing celery alot better by taking a walk.
So, eating celery and drinking ice water are just exercise, but they aren’t great forms of it, so don’t be very amazed. They burn tiny amounts of calories. Take a walk or climb some stairs.
While it’s not literally true, if you ate nothing but celery, you probably would lose weight. Your body needs 2000 calories a day, more or less, as just plain basic fuel. Celery has so few calories, and has much bulk, that I don’t think you could eat enough in a day to meet your quota.