Point of diminishing returns with fasting?

#1

I’ve been doing IF three days varying between 18/6 and 23/1, followed by a 48-hour fast for 2 weeks. My BMR is 23.2 and my body fat is about 31% based on Army tape test. My question: is there a point of diminishing returns with fasting in this pattern for too long?

(Tim) #2

I believe I recall Dr. Fung saying it is something between 3 and 5 days for most people. I don’t recall the exact source on that, and I’m sure it varies person to person depending on physical and hormonal state.

I’ll try and find a link if I can remember where I heard it. Pretty sure it was a podcast somewhere.

(Siobhan) #3

Depends I guess. I find that if I fall into a pattern for too long I tend to find that my body gets used to it.
You may find it useful to switch it up occasionally, throw in a fast for a different purpose if you want like cancer prevention.
But it depends entirely on why you’re fasting. Weight loss? Cancer prevention? Insulin sensitivity? Convenience?

If weight loss it would probably be beneficial not to fall into too much of a pattern lest you adapt to it.

#4

Siobhan, fat loss, insulin sensitivity, and autophagy are my goals. But I’m worried that if I continue my fasting pattern for too long I’ll lose lean mass.

#5

Don’t be concerned with this. Fasting does not cause you to lose lean muscle mass. It is one of the more persistent of the myths around fasting. In fact, Growth Hormone actually increases on an extended fast past the 24-36 hour time frame. Growth Hormone preserves muscle. Protein oxidation (burning of muscle) actually decreases so rather than burning the muscle we conserve it. I reread The Complete Guide to Fasting by Jason Fung MD and Jimmy Moore to help me cope with doubts and confusion. You may be interested in it as well.

(Tim) #6

This will not happen. I’m on 51 days and have yet to lose lean muscle mass.

#7

To reference Jason Fung MD from The Complete Guide to Fasting (page 125): (this is if you are fasting to lose weight) "You’ll probably eventually experience a weight-loss plateau as the weight lost during fasting begins to match the amount regained during eating. (The only way not to plateau at all is to continually fast for weeks or months at a time: otherwise, reaching an equilibrium is inevitable.) Changing either your fasting regimen or diet or both may help…the key is simply to change the fasting protocol.

(KCKO, KCFO 🥥) #8

These podcasts should put your mind at ease about protein & muscle loss, etc.


#9

Thank you!

(Siobhan) #10

Dont worry about it. Your body is VERY good at being thrifty about and recycling protein when it needs to. Thats part of what autophagy does id take broken protein and recycle it as much as possible. There are people who have fasted for a month straight and not lost lean mass.

As long as you have adequate body fat, your body will not touch muscle for fuel.