A fascinating but unfortunately locked review article on the psychology of vegetarianism has this paragraph on how avoiding the pleasures of cooked flesh has been seen as a mental illness in times past.
How vegetarians are seen has shifted radically over time. During the Inquisition, the Roman Catholic Church declared vegetarians to be heretics, and a similar line of persecutions occurred in 12th century China (Kellman, 2000). In the earlier half of the twentieth century, the sentiment toward vegetarians remained distinctly negative, with the decision not to eat meat being framed as deviant and worthy of suspicion.
Major Hyman S. Barahal (1946), then head of the Psychiatry Section of Mason General Hospital, Brentwood, wrote openly that he considered vegetarians to be domineering and secretly sadistic, and that they “display little regard for the suffering of their fellow human beings” (p. 12). In this same era, it was proposed that vegetarianism was an underlying cause of stammering, the cure for which was a steady diet of beefsteak.
In contrast, research shows the general attitude to vegetarianism has generally shifted to be, shall we say, somewhat more positive.
Link to locked article. Forbidden fruit and all that.