[Expez]

Another effect leading to weight fluctuations upon starting / ending a diet is the body's usage of glycogen stores as an energy source. For every gram of carbs the body stores as glycogen it stores around 4g of water along with it. Thus, when you burn through all the glycogen in your liver and muscles you will lose a lot of water weight, several kilos in fact. This weight will also be regained when you start eating normally again.