Baba stated:

The body will survive for 95 days if one remains only on water. Just as the body feeds on food, so the mind feeds on desires, and indulgence in these desires feeds the mind and the ego. So, by starving the mind of these desires, the ego becomes very thin and weak.

In a physical fast, taking only water, lust is lessened, but anger and hope are increased. During the first three days of a fast, hunger is marked, depression is strong, anger is strengthened and lust is diminished. From the third to the seventh day, there is a fluctuation in feelings: hunger, depression, anger and lust are all lessened, while hope — for everything — is still strong. On the tenth day, the feelings again swing back, and there is increased hunger and anger. This lasts until the 14th day, when the feelings again become calm and remain calm. Thus, after the 14th day, a fast has no spiritual value!, p-2259, Jan, 1942; Meherabad

Fasting does not increase love. No connection exists between them. All austerities, repetition of God’s name (japas), penances, et cetera, are quite apart from this fast I am telling you to do. Therefore, as long as I do not ask you to fast, why should you? If you want to fast on your own, fast in such a way that your stomach remains full while your mind starves! This is the best fast.

(Lord Meher, 1st. ed., Bhau Kalchuri, Vol. 13, p. 4782)

There is no necessity to starve the stomach. You can do it for your health, but not for spiritual reasons. We are in the habit of eating food at regular intervals. With a few exceptions, when we feel hungry our stomach craves for food, although we may be engrossed in some other work. But when the mind is occupied in some work, the stomach feels satisfied. It is our nature to look at the clock when it is time for food. If we purposely fast, our eyes would constantly be on the clock to see if it is time to break the fast. By such fasting, the bindings become strong. When I ask you to fast, it is something different.

Lord Meher, 1st. ed., Bhau Kalchuri, Vol. 13, pp. 4821 - 4822.