In endocannibalism, typically or often, it was believed that the, "ritual consumption of parts of the human body enables the consumer to acquire something of the body's vital energy" (I.M. Lewis, "Religion in context, cults and charisma, P. 73, quoted in "Culture in the Domains of Law" edited by René Provost, P. 338) Which can include the consumption of enemies killed in war, whereby, "The eating of flesh, especially organs, serves to absorb the power of their victims and thus to enhanced their own strength." (Denis Tull, Ibid) All of which is consistent with the conclusion that endocannibalism recycles and regenerates social forces that are believed to be physically constituted in bodily substances or bones." (Peggy Reeves Sanday, Ibid) Through absorption and incorporation, the eaten is not simply devoured and annihilated, but rather becomes integrated in some way with the eater. Provost, Ibid, P. 339) )Sir James George Frazer (1854–1941) mentioned before, of questionable veracity also states,
The custom of eating bread sacramentally as the body of a god was practised by the Aztecs before the discovery and conquest of Mexico by the Spaniards." The May ceremony is thus described by the historian Acosta [José de Acosta, SJ (1539 or 1540) Spanish Jesuit missionary and naturalist in Latin America]: “
“The Mexicans in the month of May made their principal feast to their god Vitzilipuztli,...all the virgins came out of their convent, bringing pieces of paste compounded of beets and roasted maize,... They called these morsels of paste the flesh and bones of Vitzilipuztli...This ceremony and blessing (whereby they were taken for the flesh and bones of the idol) being ended, they honoured those pieces in the same sort as their god...
And this should be eaten at the point of day, and they should drink no water nor any other thing till after noon: they held it for an ill sign, yea, for sacrilege to do the contrary:...and then they gave them to the people in manner of a communion, beginning with the greater, and continuing unto the rest, both men, women, and little children, who received it with such tears, fear, and reverence as it was an admirable thing, saying that they did eat the flesh and bones of God, where-with they were grieved. Such as had any sick folks demanded thereof for them, and carried it with great reverence and veneration.”
...They believed that by consecrating bread their priests could turn it into the very body of their god, so that all who thereupon partook of the consecrated bread entered into a mystic communion with the deity by receiving a portion of his divine substance into themselves....
The doctrine of transubstantiation, or the magical conversion of bread into flesh, was also familiar to the Aryans of ancient India long before the spread and even the rise of Christianity. The Brahmans taught that the rice-cakes offered in sacrifice were substitutes for human beings, and that they were actually converted into the real bodies of men by the manipulation of the priest....At the festival of the winter solstice in December the Aztecs killed their god Huitzilopochtli in effigy first and ate him afterwards. - http://www.bartleby.com/196/121.html
Mormonism has an interest in this: http://archive.timesandseasons.org/2005/07/endocannibalism-in-sacrament-meeting/ ; http://olivercowdery.com/texts/1604Acos.htm