St. John Chrysostom writes of St. Lucian:
He scorned hunger: let us also scorn luxury and destroy the power of the stomach that we may, when the time that requires such courage comes for us, be prepared in advance by the help of a lesser ascesis, to show ourselves glorious at the time of battle.
The part that I find most helpful is the bit about doing “lesser ascesis.” It confirms that fasting and denying oneself has benefit in the future when larger temptations come our way. Lesser ascesis is, according to Tito Colliander in his excellent little book, “Way of the Ascetics,” warfare directed against the life of self-will. He puts it this way,
If you have the urge to ask something, don’t ask! If you have the urge to drink two cups of coffee, drink only one! If you have the urge to look at the clock, don’t look! If you wish to smoke a cigarette, refrain! If you want to go visiting, stay home!