How long does it take for the body to use its own fat once stopping eating?

[cass8008]

I'm not anorexic or considering becoming anorexic, but someone asked this question and no one knew the answer. How long would it take for the body to start using up its own fat and muscle tissues, and how much weight is lost in how much time once someone stops eating?

[Scarlett]

It depends on how much fat that person has in the first place.From my own experience, if your stomach is empty and tells you it wants food, and you ignore it, then you have to get your energy from somewhere else. So, it is at that point that you start using your reserves. If you eat too much, your reserves are stored as fat. If you use more energy than you have food to use, it comes off your body. But bear in mind it will come off the place you least want! ie- boobs and wrists always first!!

[lafrancaise]

I was told by a nutritionist that the body starts using its reserves after 40 minutes exercise. This of course is for somebody who is eating normally. It was to show us that the odd spurt of exercise doesn't do anything, so really by doing an hour of sport is more beneficial than 2 half hours.