In the Xianxia Novel I Shall Seal The Heavens, the protagonist comments on one aspect of Immortality:
After becoming an Outer Sect disciple, he thought to himself, he hadn’t been eating as much as when he was a servant. As long as you had enough Spirit Stones, you could take them to the Sect’s Pill Cultivation Workshop to exchange them for Fasting Pills or Appetite Control Pills. It was said that one drop of such a pill would prevent hunger for days. Without them, people would have to spend time worrying about finding food.
Xianxia is a genre built like an RPG game, with specific levels and criteria to reach the next level, until the protagonist becomes an entity that can straight up destroy the thousands of galaxies and heavens. These criteria are based, usually, on various traits of Chinese religion. Thus, Campany’s translation of Ge Hong’s Traditions of Divine Transcendent contains the following note:
By far the most common dietary avoidance mentioned in Traditions, Inner Chapters, and texts of the Grand Purity patrimony, however, was “grains” – the entire class of cereals, the staple food group of the Chinese diet… “grain” in such contexts seems to have been intended synechdochally, standing for “food” in the sense of items comprised in the culturally mainstream diet…When Wang Chong attacks “grain avoidance” he clearly understands the practice to entail not eating normal foods at all and consuming qi instead. Several passages in the Five Numinous Treasure Talismans promise that those who ingest the prescribed medicinals will need to eat no other foods, and the benefits claimed for some compounds include appetite suppression.
Of course, it isn’t really a far stretch of the imagination to say that a person who is on the way to becoming an Immortal will eventually have no need for food. Still, it’s interesting to see how such a notion can be traced back to a rejection of the agricultural ‘mainstream’. Marcel Mauss also has a thesis that a Magician is a person who is defined by his being on the opposition of the mainstream. This is why he doesn’t exactly define a priest that can collaborate with Angels as a ‘Magician’, because they are still working under the sign of the mainstream religion.