Glycogen storage causes significant water storage. If you deplete your glycogen, you'll lose a significant amount of water weight. This is why people lose so mu

Glycogen storage causes significant water storage. If you deplete your glycogen, you'll lose a significant amount of water weight. This is why people lose so much when they first start dieting. 12 pounds in a week of a real fast seems reasonable for someone who weighs 170. Call it 4 pounds of fat and 8 pounds of glycogen and water.