It is not by abstaining from food that you can make a spiritual progress. It is by being free, not only from all attachment and all desire and preoccupation with food, but even from all need for it; by being in the state in which all these things are so foreign to your consciousness that they have no place there. Only then, as a spontaneous, natural result, can one usefully stop eating. It could be said that the essential condition is to forget to eat—forget, because all the energies of the being and all its concentration are turned towards a more total, more true inner realisation, towards this constant, imperative preoccupation with the union of the whole being, including the bodily cells, with the vibration of the divine forces, with the supramental force which is manifesting, so that this may be the true life: not only the purpose of life, but the essence of life, not only an imperative need of life, but all its joy and all its raison d’être.
Ref : Questions and Answers 1957-1958