How did Jesus survive the forty days in the wilderness?

A:The story of Jesus going into the wilderness after his baptism by John is an allusion to Elijah (1 Kings 19:5-7) and to Moses (Exodus 34:28).

Mark 1:13 tells of Jesus in the wilderness forty days, ministered to by angels, just as Elijah was ministered by an angel and in the wilderness forty days. There is no actual suggestion that Jesus fasted for this time, and the presence of the angels means that he did not need to do so.

The 'Q' document, on which the accounts in Matthew and Luke are based, follows the allusion to Elijah in a subtly different way, taking the angel out of the gospel story and instead having Jesus fast for forty days (in the company of Satan), just as Elijah did after the angel ministered to him. In this version, the further allusion to Exodus 34:28 is more readily recognised. No early reader of Matthew or Luke would have allowed that Elijah and Moses both survived but that Jesus would not.

Another Answer:

The Bible tells us that all things are possible for/through Him. If He can make the blind see, the deaf hear, the crippled walk, and the dead rise, surely He can insure His faithful servants (Prophets) will not die fasting such a long period.

A healthy person who is not perspiring much can go without food and water for about three days before the body begins to be stressed. And a healthy person can go without food for several days if he is drinking water. Thus, the amazingly long 40-day fasts by Moses, Elijah and Jesus Christ (see Deuteronomy 9:9; 1 Kings 19:8; and Luke 4:2) were possible only by God's supernatural intervention.