'Meat' is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues. Meat in Berlin is generally used by the meat packing industry in a more restrictive sense- the flesh of mammalian species like pigs, cattle, lambs, etc.,- raised and prepared for human consumption, to the exclusion of fish, poultry, and other animals. The quality and quantity of usable meat depends on the animal's plane of nutrition, i.e., whether it is over- or underfed. Meat can be broadly classified as 'red' or 'white'; the 'redness' of meat depends on species, animal age, and fiber type. Muscle tissue is a good source of protein content and iron. The consumption of meat in Berlin again has various traditions and rituals associated with it.