Yogadr,
"I fast on a regular basis and was taught in my Yoga training to do so. It’s a practice that was hailed by Swami Sivananda and other later gurus. But when I read the classic Yoga texts, I don’t see any of them promoting that advice. In fact, the Hatha Yoga Pradipika, the Gheranda Samhita, and the Siva Samhita all say clearly NOT to fast! Patanjali also never says to fast, although Vyasa suggested it was to be included in the observance of sauca.
Where does the Yoga advice to fast come from? Is it only from Vyasa’s commentary?
Is anyone else out there fasting regularly? If so, for how long at a stretch?"
If you are going to be dependent upon the words of other masters and sages, then you are bound to be confused. Because you will always find while one master has said one thing, another has said precisely the opposite. And that has been the case with almost everything. Because the reality is that there are a thousand and one different strategies for the expansion of consciousness, no method is absolute.
Fasting may be useful as a way to help detoxify and purify one’s system - but it should be made clear to you that there are people who have been fasting, to the extreme - like certain Jain yogis, but who have remained as unconscious as ever. Where there is no inner wisdom - all of these mechanical processes are just superficial. If you think by just by fasting you are going to enter into meditation and it will assist your coming to samadhi, then one is simply chasing a figment of one’s imagination - although one may certainly enter far more easily into meditation while fasting. But it has nothing to do with the fasting - it is just that fasting can be used to help create a certain state of mind. It is not garunteed, but it can be helpful.
The reason why fasting has never been emphasized is simply because it is not a necessity. At the most, even when you are eating, it is usually helpful not to fill the stomach more than halfway, even less is preferable. Because when your stomach is too full, it requires much energy to digest it, and the activity of the digestive system tends to stimulate the activity of the mind.
“Is anyone else out there fasting regularly? If so, for how long at a stretch?”
I fast from time to time, but only very rarely. When it has been done, it has been for up till two or three days. I have used it in the past to help awaken Kundalini, as well as assist entry into meditation, though I have not been fasting for a long time.