[MightySunTzu]

Originally Posted by koneall

I've done fasts up to ten days. In a fast the body goes into ketosis as fat is released from the stores and used for energy. But at the same time the body is breaking down muscle. The Krebs cycle requires a small amount of glucose to keep it spinning. It gets the glucose from muscle tissue..

Hi koneall,

I agree with all of the above.

Originally Posted by koneall

So anything more than ten days and you begin to lose muscle mass. Also I found I did better if I took sodium in the form of bullion cubes dissolved in hot water. Without it, I eventually developed cramps..

This is where we begin to respectfully disagree. Actually we are losing a small amount of protein tissue from the very early going, i would say within about 24-48 hours of the onset of the fast, once the stored carbs have been exhausted. There is nothing magical about the 10 day mark bringing with it an increase in muscle burning. In fact, the 2nd and/or 3rd days are where protein burning peaks as the body is making its transition into ketosis (fat as fuel) and from here there is a precipitous drop. Thus, the tenth day and beyond burn far less protein than this 2nd or 3rd day. Once the body has made this move into ketosis, fat : protein is burned at about 10:1 and at no point does this ratio become any less protein-sparing unless and until the body was to complete the fast and then begin to starve, something the body would be screaming intensely, unmistakably and unrelentingly at the faster to avoid, a powerful phenomenon i have been fortunate enough to excitely experience first hand. When the fast is completed, the need to eat becomes all-encompassing.

Ketones, a product of ketosis can accomplish many of the tasks that the body had been relying on glucose (from protein) to perform in the 2nd and/or 3rd day, so through this feature, after the brief transitional period, the conservation of muscle is greatly heightened. After ketosis has set in, the body primarily continues to convert tissue to glucose only to fuel the brain.

Let it be restated that the body in its immeasurable intelligence will preferentially burn the most diseased or otherwise damaged tissue first, so often the 1:10 tissue burning aspect of a fast can be lifesaving and should thus be welcomed.