> On a more serious note: "even though it was “understood that the custom of eating flesh corrupts the body.”

The source material [0] that the quote is taken from has a footnote that says "The Cistercians held that rich food increases sexual appetite"

It would seem that the "corruption" here is related to keeping ones libido in check.

[0] https://books.google.com/books?id=cBqgOXfMxAoC&pg=PA26&lpg=P...