The title is (mildly) tendentious. It is a reflection on the only fast that the Gospels relate Christ performing:
for the space of forty days, [Christ] was tempted by the devil. And he ate nothing in those days. And when they were ended, he was hungry.
For many years, I can remember thinking “No, after forty days he was dead”. The body has some minimal nutritive needs, which seem far transgressed by forty days of eating nothing. There seem to me to be only three ways of preserving the letter of the text:
1.) We claim that the fast was wholly miraculous. Most commentators on the passage did not take up this question at all, but Matthew Henry does claim in passing that the fast was wholly miraculous. But if this is so, could we say that Christ taught us how to fast? When Christ miraculously heals a leper, he isn’t showing us how to treat lepers; and his feeding of the multitude isn’t showing us how we should feed a group of several thousand.
2.) We can distinguish the senses of “day”. In one way, one day is opposed to another: like Monday to Tuesday; and in another way, day is opposed to night. The first sort of day is a twenty-four hour period, the second the period of daylight. On this interpretation, we say that Christ did eat what one could find in the desert after sundown.
3.) He ate nothing, but drank something. I’d have to check this out. I have my doubts that one could meet minimal nutritional needs with simply the fluids he finds while alone in the desert. Water has no calories.
On the latter two interpretations, the sense of Christ being hungry after forty days would be he was at his physical limit of tolerating minimal needs.