Thomas Aquinas

“ Now pleasures of the table are of a nature to withdraw man from the good of reason, both because they are so great, and because food is necessary to man who needs it for the maintenance of life, which he desires above all other things. Therefore abstinence is a special virtue.
Reply to Objection 1: Virtues are of necessity connected together, as stated above (FS, Q [65] , A [1] ) . Wherefore one virtue receives help and commendation from another, as justice from fortitude. Accordingly in this way the virtue of abstinence receives commendation on account of the other virtues. ”

“ Now there is no special virtue in being content with moderate clothes. Neither, therefore, is there in abstinence which moderates food.
On the contrary, Macrobius [*In Somn. Scip. i, 8] reckons abstinence as a special part of temperance.
I answer that, As stated above (Q [136] , A [1] ; Q [141] , A [3] ) moral virtue maintains the good of reason against the onslaught of the passions: hence whenever we find a special motive why a passion departs from the good of reason, there is need of a special virtue. ”

“ Objection 2: Further, Augustine [*Fulgentius] says (De Fide ad Pet. xlii) that "the saints abstain from meat and drink, not that any creature of God is evil, but merely in order to chastise the body." ”