They also found that the eating of greens or pulse did not agree with everyone, and that not everyone could live on dry bread. One man, they said, could eat two pounds of dry bread and still be hungry, while another might eat a pound, or only six ounces, and be satisfied.
As I said, the Fathers have handed down a single basic rule of self-control: ‘do not be deceived by the filling of the belly’ (Prov. 24:15. LXX), or be led astray by the pleasure of the palate. It is not only the variety of foodstuffs that kindles the fiery darts of unchastity, but also their quantity.
Whatever the kind of food with which it is filled, the belly engenders the seed of profligacy. It is not only too much wine that besots our mind: too much water or too much of anything makes it drowsy and stupefied. The Sodomites were destroyed not because of too much wine or too much of other foods, but because of a surfeit of bread, as the Prophet tells us (cf. Ezek. 16:49). Bodily illness is not an obstacle to purity of heart, provided we give the body what its illness requires, not what gratifies our desire for pleasure.
Food is to be taken in so far as it supports our life, but not to the extent of enslaving us to the impulses of desire. To eat moderately and reasonably is to keep the body in health, not to deprive it of holiness.
Based on Saint John Cassian
Candid shots from mill of the Vatopedi monastery, Mount Athos