The exact definition of white meat varies by time, place, and culture, but domestic chicken and rabbit are invariably considered "white", while the meat of adult mammals, such as beef, mutton, and horse is invariably considered "red". The meat of young mammals such as veal and milk-fed lamb are considered "white"; while the meat of duck and goose is considered "red", though the demarcation line may be changing. Game is sometimes put in a separate category altogether (French viandes noires 'black meats').
A newer definition in the United States of America emphasizes not the appearance and strength of taste, but the fat content, making "white meat" synonymous with "lean meat"; traditionally "white" meats such as lamb and veal are reclassified as "red". Even fish and seafood, including fatty and dark-fleshed fishes such as salmon, mackerel, and tuna, are called "white meat".
Given nutritional concerns, meat producers are eager to have their products considered as "white", and the United States National Pork Board has positioned pork as "the other white meat", alongside poultry; however, meats which are red when raw and turn white on cooking, like pork, are categorized by the United States Department of Agriculture as red meats.