It's generally assumed that a pound of fat on your gut is 7,000 calories. It's also assumed that a male needs about 2,500 calories per day. More than this and he puts weight on. Less, and he loses weight. Now, this is the bit I don't understand. People say that they lost two pounds in a week. Now this is 14,000 calories of blubber, whereas the normal intake for a week would be 17,500 calories. Some say that they've lost three pounds, which is 21,000 calories. Does this mean that they've had nothing to eat all week?