Chicken McNuggets are a type of chicken nuggets sold by the international fast food restaurant chain McDonald's. They consist of small pieces of reconstituted boneless chicken meat that have been battered and deep fried. Chicken McNuggets were conceived by Keystone Foods in the late 1970s eventually leading to their introduction in select markets in 1981. The nuggets were made available worldwide by 1983 after the fixing of a supply issue. The formula was changed in 2016 to remove artificial preservatives and improve the nutritional value.