Frozen meat weighs more than thawed meat, because the water and other liquids emerge as the meat thaws. Some meat manufacturers include an absorbent surface inside the packaging to soak up this liquid so it does not spill when the consumer opens the package.
Poultry and meat are made of bone, fat, connective tissue and muscle. The muscle is about 20 percent protein and 75 percent water, with the rest coming from fat, minerals and carbohydrates. Before cooking, an eye of round roast contains 73 percent water. When meat packers freeze their products, the water becomes solid ice crystals in the meat and contributes to the weight, but when the consumer thaws the meat, it is possible to lose as much as a third of the size and weight as the juices drain.