Ask any scientist, philosopher, of this world, that "Can you show me any way, no more eating, no more sleeping, no more mating and no more defending?" That is spiritual life. Therefore we have to reduce it. It is not possible, but there is possibility. Just like Raghunatha dasa Gosvami. Raghunatha dasa Gosvami, he made it in his life, during Caitanya Mahaprabhu's… Even after departure of Caitanya Mahaprabhu, about four hundred years ago. He was a very rich man's son. Very good wife, very good state. He left everything, and ultimately, he made these things, even eating, nil. He was eating every third day a small quantity of butter, nominal, little. Otherwise he gave up eating. So it is possible. It is not that "How one can give up eating and live at the same time?" That is possible. By the life of Raghunatha dasa Gosvami we see.

(From Srila Prabhupada's class on Srimad-Bhagavatam 1.16.6 — Los Angeles, January 3, 1974)