AskHistorians

Not a historian, but here's the general consensus per Wikipedia:

Cannibalism in the Americas has been practiced in many places throughout much of the history of North America and South America. The modern term "cannibal" is derived from the name of the Island Caribs (Kalinago), who were encountered by Christopher Columbus in The Bahamas. While numerous cultures in the Americas were reported by European explorers and colonizers to have engaged in cannibalism, some of these claims may be unreliable since the Spanish Empire used them to justify conquest.[1]

At least some cultures have been archeologically proven beyond any doubt to have undertaken institutionalized cannibalism. This includes human bones uncovered in a cave hamlet confirming accounts of the Xiximes undertaking ritualized raids as part of their agricultural cycle after every harvest. Also proven are the Aztec ritual ceremonies during the Spanish conquest at Tecoaque. The Anasazi in the 12th century have also been demonstrated to have undertaken cannibalism, possibly due to drought, as shown by proteins from human flesh found in recovered feces.

There is near universal agreement that some Mesoamericans practiced human sacrifice and cannibalism, but there is no scholarly consensus as to its extent. Anthropologist Marvin Harris, author of Cannibals and Kings, has suggested that the flesh of the victims was a part of an aristocratic diet as a reward since the Aztec diet was lacking in proteins. According to Harris, the Aztec economy would not support feeding enslaved people (the captured in war), and the columns of prisoners were "marching meat." Conversely, Bernard R. Ortiz de Montellano has proposed that Aztec cannibalism coincided with harvest times and should be considered more of a Thanksgiving.