When you reduce your caloric intake, your body gets its needed energy by releasing and utilizing its stores of glycogen, which is a type of carbohydrate found in the muscles and the liver. Glycogen holds onto water, so when glycogen is used and burned up for energy, it also releases the water it holds onto. This is about 4 grams for every gram of glycogen. This results in the initial “water weight” loss that accompanies early weight loss from dieting and calorie restriction.”