Yes, great article. I remember reading it years ago. Aside from fasting, it actually helped me to understand macro requirements just for keto in general, and how they differ for different people. When I first went keto, and so was just learning, I did the usual of lowering carbs to less than 20 grams and finding healthy proteins and fats to eat instead. I had heard that in order to not be hungry, eat more fat. And, a family member who was already keto said she included fat bombs to ensure enough fat. So, I made up a batch of fat bombs to have. I kept finding though that I didn’t need them, didn’t crave more fat, didn’t want them, they actually kind of repulsed me. I didn’t understand why she used these so much and I couldn’t. Then, I learned about the body fat factor and around then I also saw the above article. My body had plenty of fat to draw from and I really did not need to be consuming so much. Her body was actually pretty lean and fit and so she did need extra fat just to get through the day as a person on keto. Lightbulb moment. So, this applies to both fasting and day to day keto. We aren’t all the same, and so can’t expect the same macros as our neighbor, and as time goes by we aren’t even the same as we used to be, and so we need to adjust, and keep adjusting. At least it’s better to understand it than just be in the dark. I understand your frustration though @BlueViolet. Best wishes!
This is an awesome thread, thank you all for good info!
There is more supporting evidence Richard doesn’t supply.
AA pound of fat is equal to 3500 kcal. The average person might use 2400 kcal. 2400/3500= .685 pound of energy available if you can access it all. You would need 77 pounds of fat at 31 kcal per fat pound. We do see this type of loss in the early stages of our obese community. Then it tapers down.
Take Angus Barberi who fasted 382 days. He lost an average of .72 pound per day. However if you consider the amount of TDEE required to run 480 pounds, he was likely in the beginning using a pound and a half of fat a day.
Jason Fung sees an average of 1/2 per day on EFs according to his IDM blogposts. Again the math works out. Lets say you are 50 pounds overweight. That is 1550 available fat calories. 1550/3500 = .45 or just under 1/2 pound of energy consumed . Per day.
So I think it is safe to say that the Alpert paper which @richard based his premise on is accurate.
We just completed a ten day fast. After a 2 week feast we will get Dexascan- ed again. I have a calculated amount of fat I think the wife and I lost. being lean the best I could do is about 1/3 pound. She, being heavier should have lost about 1/2 of fat each. No matter what the scale says.
i’ll know next Wed. The math has always worked out in the past.
In my last ten day fast I used butter fat to help on really intense days. I try to limit it as I am fasting more for autophagy and not so much for fat loss. In my case I think the mTor trigger as well as the AMPK pathway can be tripped by the fat consumption if done too much>
This is awesome and explains a lot. Now I don’t feel so bad. I have tried to drop to one meal a day a couple of times a week and it’s not working for me. Right now I am sitting at 157 at almost 5’8 and it may be that I just don’t have enough to manage it. Last time I tried - this past weekend I got to 3 PM and had to eat something.
Why do you say that? The mToR is usually protein or insulin triggered - fat does neither.
And AMPK would be in support of autophagy so that’s a good thing?
It is true that dietary fat is broken down by the pancreas and then distributed by the lymphatic system. So it shouldn’t require insulin and thus should NOT trigger the mTor. But there does need to be some sliding switch, not a binary switch that triggers how much autophagy and when. That I have successfully correlated repairing 7 herniated disks has been verified by MRI, the worse was a 10 x 10 x 12mm protrusion into my sciatica at L5-S1. That is no longer there. Instead of being permanently disabled as my doctor pronounced I am a healthy 55 year old.
So I am trying to make sense of it because some fasts produced far better results than others judging by how I felt. Nutrient sensing , not insulin seems to be a mTor trigger.
Fasting is complex but it’s not necessarily anabolism that is helping.
First, the drop in insulin reduces fluid retention and inflammation. Oxidative stress from diet drops substantially and allows the body to focus on AMPK driven autophagy.
So the healing is catabolic first. Eating fat doesn’t necessarily retard this. In fact, it stimulates more mitochondria to process the fat effectively in the low insulin environment.
On refeeding, mToR is triggered and that’s the anabolic component of healing. Basically, the real rejuvenation benefits of fasting happen during the refeed.
So healing from fasting doesn’t need mToR signaling during the fast… just after it.
Same, just because it really helps with any hunger pangs.
I’m with you! The longest for me was about 19 hours (4pm) and that was it.
I have been able to do 24 hours like four times but that’s it. Today I couldn’t even make it from lunch (noon) to dinner. Had a snack at 3. My lunch clearly wasn’t big enough.
I was weightlifting 19 days into my extended fast.
A lot of fasting is mental.
Did you not have quite a lot of fat on you at the time though? The OP is quite compact…
I take a brisk walk every day for about 65 to 70 minutes but that’s it. I am back to a normal BMI so that may be it too.
I think your body has regulated its hormones, and that includes your hunger signalling. You are now quite small and light (pretty low bodyfat?), your body is simply signalling to you what it wants, you are listening, and you are sensitive to it. This is great!
I would recommend you trust what your body is telling you, and don’t force the fasting.
I am p small but at 116 still have fat to spare, esp on thighs Not that I GAF about appearance, I embraced hagdom at menopause. It’s more from a desire to be my “correct” size just in and of itself.
I got so mad Monday after making the thread that I went almost 48h after all; didn’t eat from Mon 6 p.m. to today (Wed) at noon (42h). It wasn’t as comfortable (no hunger vs having hunger but in waves, not constant) as in days of yore but was certainly doable. I had my one meal on Monday much later than usual (6p.m. instead of noon) and yesterday was actually OK.
Maybe what @Karim_Wassef states above about the mental aspect, kicked in for me; it being so easy until recently, as in not much hunger hours 25-48, I didn’t need much willpower. When I got annoyed enough I was able to tolerate the less comfortable state I guess.
I did eat a ton and a lot of fat today per the gurus instructions above; my new plan is to eat once/48h instead of once/24h until goal weight. I’ll report back herein with results.
That sounds great, well done. But remember rule #1 of Fasting Club: if you feel unwell, end the fast.
@Alecmcq Oh heckyeah, having med sci background I know how to recognize/assess signs of physiological distress that would be remarkable and am far too risk averse to ignore them