Now, as you know, from the physical point of view human beings live in frightful ignorance. They cannot even say exactly... For instance, would you be able to tell exactly, at every meal, the amount of food and the kind of food your body needs?—simply that, nothing more than that: how much should be taken and when it should be taken.... You know nothing about it, there's just a vague idea of it, a sort of imagination or guesswork or deduction or... all sorts of things which have nothing to do with knowledge. But that exact knowledge: "This is what I must eat, I must eat this much"—and then it is finished. "This is what my body needs." Well, that can be done. There's a time when one knows it very well. But it asks for years of labour, and above all years of work almost without any mental control, just with a consciousness that's subtle enough to establish a connection with the elements of transformation and progress. And to know also how to determine for one's body, exactly, the amount of physical effort, of material activity, of expenditure and recuperation of energy, the proportion between what is received and what is given, the utilisation of energies to re-establish a state of equilibrium which has been broken, to make the cells which are lagging behind progress, to build conditions for the possibility of higher progress, etc... it is a formidable task. And yet, it is that which must be done if one hopes to transform one's body. First it must be put completely in harmony with the inner consciousness. And to do that, it is a work in each cell, so to say, in each little activity, in every movement of the organs. With this alone one could be busy day and night without having to do anything else.... One does not keep up the effort and, above all, the concentration, nor the inner vision.
(The Mother, 24 February 1954) <ref>http://incarnateword.in/cwm/06/24-february-1954#p24</ref>