20 day fast, AKA WTF was I thinking?

(Justin Traer) #94

Phinney does say that but in one of the videos on Youtube he states that obese people seem to be spared from lean body mass loss during extended fasts.

He didn’t want to elaborate any further as it would have been speculation on his part.

(Monica Dritschel) #95

Hi! It’s amazing that you’ve done this! I am just about to embark upon a 21 day fast. I’ve done a 14 day fast before and felt so good! I have Crohn’s disease and bulimia and it seemed to really help both those symptoms, I just wish I’d worked on the issues surrounding the bulimia while fasting asnow it’s come back with a vegnance and is really making the inflammation from crohns much worse. I’m hoping to do a little bit of working out in the beginning too and try and get plenty of rest as I’ll be working 3 days a week. I’m not sure if I should take magnesium and zinc and havdbnne broth…would you recommend supplements while fasting? Do you have any tips that helped you get through the initial days too?:slight_smile:

(Tim W) #96

Good questions.

Supplements while fasting, I absolutely would take them. I wouldn’t do anything “new” like add something you have not been taking before but, if you are using something regularly, I’d continue to take it during the fast, things like zinc, mag, sodium, potassium (be careful with potassium, know your “dose”).

You have to do what works for you, I found that zinc/mag/pot/fish oil every day kept the cramps at bay and seemed to have a positive impact on overall health. I also had a keto aid daily, salt on the tongue several times a day and lots of water. I took the supplements with my coffee, that seemed to reduce the gastro distress that some items can cause when fasting and taking all of that on a truly empty stomach.

Bone broth- if it works for you and helps you continue the fast, I used it every fourth or fifth day as needed.

Tips to get through the initial days:

  • Ensure that you eat lots of fats in the days before the fast
  • Have a good support system, my wife and I fast together, making it much easier
  • Know you why, why are you fasting? Write it down, refer to it
  • Know that it gets easier, if you are in good health (more on that in a minute) then fasting will often get easier sometime after day 3 or so, it varies from person to person when you “get over the hump” but it truly does get easier in many cases

Now, the elephant in the room. If you have an eating disorder, does it make sense to play with this protocol? I’d be hesitant to suggest it. If one of my kids/friends/co-workers suggested something like this and I knew they had an eating disorder, I’d suggest they stay away from fasting until they gain control of that issue.

Are you seeing anyone about that?

(Monica Dritschel) #97

Thankyou for all your tips! Yeah I’ll try taking the supplements with coffee and salt under the tounge-I didn’t do that last time which may have been why I felt a bit dizzy sometimes. I know my current state of health from crohns is not at all good and this is the primary reason while I’m doing this. I believe bulimia is a primarily a habit as well as a coping mechanism and having time and space away from food to reflect on what the emotions and triggers are for the behaviour could really help. I’ve been to see multiple people about the bulimia but I still haven’t been able to break the habit. The only time I’ve cone close is when I completed my 14 day fast previously. I’m a bmi of 24.5 so I felt as though I would be safe enough to try fasting to try and feel physically better as well as having a fresh start at life! It would be great to be able to do this with someone else but I’ve found a fasting hypnosis on YouTube which seems to really help me to keep going as well as the support on these forums! I know it does get better once you break through the initial days, the cravings for food really do go away. I’m up for this challenge, I really think it’s something worth trying and that fasting can do miricles for your body and mind! I’ll let you know how I get on, thanks for getting in touch :slight_smile:

(Richard Hanson) #98

Hi Ron,

Thanks for your informative post.

I do think that Dr. Fung was a bit … well overreaching in some of his blog post comments and I love this informational dense graphic.


First, the initial state of the graph appears to be someone eating a SAD diet where the body is utilizing a mix of fuels. If we total the three we are looking at about 2300 kcal/day to 2400 kcal/day. (day -5)

So the main question is this – if you fast for long enough, doesn’t your body start to burn muscle in excess of what it was doing previously in order to produce glucose for the body. Hell, no. Dr. Fung.

This conclusion is not supported by the graph presented. At the initial sate, the body was fed and we can not say if the body was metabolizing exogenous or endogenous protein, or both. At some point, there will be no more exogenous protein as whatever was in the digestive system at the time the fast was initialized will have been depleted. The issue is that in Dr. Fung’s statement, “your body start to burn muscle” should read your “body start to burn protein”. It might well be that the source of that protein was primarily exogenous at the beginning and primarily LBM at the end.

If we interpret this graph as typical of someone who is eating SAD and starts an extended fast, the we can see the spike in carb burning, coresponsing with the utilizaiton of stored glycogen at the start of the fast, followed by a very rapid decline to a basel level of about 50 g/day which is the rate at which the body would produce glucose to fuel the brain after fat adaption, gluconeogenesis. We see a transition form exogenous to endogenous utilization of glucose.

On the protein curve, we also see an initial upswing in protein utilization at day 0. This is consistent with the body temporarily utilizing protein as an emergency source of fuel while fat burning is ramping up.

But anywho, this is a graph of where the energy to power our bodies comes from, from the start of fasting. At time zero, you can see that there is a mix of energy coming from carbs, fat and protein. Within the first day or so of fasting, you can see that the body initially starts by burning carbs (sugar) for energy. However, the body has limited ability to store sugar. So, after the first day, fat burning starts. Dr. Fung.

The graph does not show “where the energy to power our bodies comes from”, it shows what fuels the body was burning for energy. The source of that energy is changing dramatically over time form energy in our diet to energy stored in our body.

What happens to protein? Well, the amount of protein consumed goes down. There is certainly a baseline low level of protein turnover, but my point is that we do not start ramping up protein consumption. We don’t start burning muscle, we start conserving muscle. Dr. Fung.

The data presented in the graph do not support this conclusion. If initially, the source of protein was exogenous, and at the end the source of protein is endogenous then just the opposite is happening, the body is starting to burn LBM, it is starting to burn muscle as it no longer has a dietary source of protein. Yes, the total use of protein as a source of energy is declining over time, but the graph does not show the source of that protein.

I still love this graph, not so much as an attempt to sustain a conclusion that fasting does not result in the loss of LBM, but what is happening when someone stops eating a SAD diet and transitions into a state of ketosis.

Finally, I would note that at the end at day 30, total energy expenditure is about 1300 kcal/day to 1400 kcal/day which is not inconsistent with the view of Dr. Phinney that fasting results in a slowing of metabolism.

I am a big fan of Dr. Fung, but I also think he has a tendency to … overreach a bit in his enthusiasm. This is an example of that behavior and my personal preference is for those who are much more conservative in their conclusions, acting with prudent caution.

Oh … did I say that I love this graphic? I would love to see a similar graphic where the initial state was people eating ketogenic instead of SAD.

Keto for Life!

Best Regards,

(Michael Tranchina) #99

I agree that there may be downsides that offset positives in healthy, lean folks when doing longer fasts…However, Science supports longer fasts for treating chronic disease…

Check out this documentary “The Science of Fasting”:

Autophagy does seems to be more than and ideology…

(Monica Dritschel) #100

wow that really gives me a lot of hope as a sufferer with crohns disease, which is chronic. The refeeding process following a fast though must be equally as important…I felt immense relief from symptoms after a 14 day fast. I hope this 21 day fast will be even an even higher step up in the healing process of this. So far i have had no stomach pain, although i am only on day 1, I’m not sure what the detox symptoms are going to be like further down the line. Thanks so much for posting this :slight_smile:

(Bella Tricks) #101

Hey, i just caught up with your thread. well done.
any further reflections?
This is great. again…well done

(Tim W) #102

Thanks for the comments.

I started to type that my further reflection would be “just don’t do it” but that’s not helpful is it :smile:

So, having put some time between the long fast and now, I’m ready to do another one, maybe up to 30 days, it would involve daily coffee and HWC due to my low body fat and desire to keep active. It would also involve plenty of bone broth and maybe MCT oil. Lastly, it would ONLY be done during the heat of the summer, the long fasting makes me too cold to even consider doing it any other time.

We did wish we had thought out our timing a little better, we are beer snobs and missed all the Sept beer fests (but maybe that’s a good thing?).

Otherwise, we had done a lot of fasting already so the lessons that we keep learning (how integrated food is to everything in the US society, how un-healthy most of the country is when it comes to food, how you CAN survive without six meals a day etc) we re-enforced but we didn’t have any other revelations, other than it’s hard, it’s doable, and we (the human species) are so much more capable than we give ourselves credit for.


Great thread. I am keeping Cancer at bay using fasting. I now try to water/coffee/tea fast for 3-5 days each month. My BMI is about 20.5, and I am older woman with estimated body fat 25%, so consider that only borderline lean.
I am finishing Day 5 of my current fast.
Any comments from other members who are “correct weight” and fasting for autophagy benefits? How often do you fast, and for how many days?
I love the “high” I get on or about Day 4.
My ketones are up around 7.9, and my blood glucose is hovering around 2.7.
Feeling fine! DH roasted a chook in our new Dutch oven. Lol. He did the dishes for his perfidy. :stuck_out_tongue_winking_eye::stuck_out_tongue_winking_eye:

(MLD) #104

Matamoros - first - best wishes to you. Not sure of the autophagy benefits but have seen really interesting data on ketogenesis and cancer. Good for you for beating back C. Respect.

Hi to all! On Day 8 of what was supposed to be a 7 day fast, now headed for 11 maybe (hard cutoff due to need to refeed over 2-3 days before traveling for business). Am an insulin resistant headed-for-prediabetic female a year ago - aged 60 now - with a genetic connective tissue disorder. Lots of management issues but over the past couple of years pain has shot to the top of the stack. Started a keto diet a year ago to try to knock down inflammation and it has been awesome, but my ol’ buddy inflammation started creeping back up again, and I’ve still got markers for insulin resistance to boot (though much better than a year ago). So trying a fast to see if we can make more of a dent. Planning to follow this up with IF for the next several months. Started ketosis w/BMI around 30, down now to about 25. Don’t really expect much of a change from the fast. NOT a water fast - doing broth, coffee, herbal tea, green tea, ACV with water a couple of times a day. Total caloric intake is probably around 40 kcal/day. Also doing vitamins, Omega 3, supplementing sodium, potassium, magnesium, calcium, and getting ready to do a low dose phosphorus supplement when I start refeeding. This is my first fast > 72 hours and the journey is really interesting. Not hungry, high energy, high mental clarity, thinking about food now and then but not obsessing (after the 2nd day that is). Thinking that having been in ketosis for the better part of a year probably made the transition easier than if I hadn’t been. Interesting to read the points of view on this thread…have been doing physical therapy as per usual (I’m in it 5 days a week) and haven’t noticed any performance degradation after the 3rd day; in fact felt really good today. Which I’d had a DEXA before (we did blood work before and again today, everything’s looking good) to do one after too, but will save that for next time. (If there every is a “next time”. Feeling good but not interested in making this a way of life.) Thanks for contributing and giving me some really good reading material…I’m a technical type and a science geek, and read about both keto and this for 3 months or so after jumping in. Happy ketoing!

(Tim W) #105

I did some business travel and hard core admin work on a 15 day fast, I found that the travel was easier since I wasn’t concerned about food. I was cold the entire time though… That’s in another post.

Excellent work so far, keep it up!

(I am a Dog (Dog's eat until they burst!)) #106

@dittmarml Last year I fasted for most of my business trips even with all of the meals. I simply drank coffee and joined in the conversations around the table.

Glad to hear you find fasting easy and enjoyable and good luck moving forward!

(MLD) #107

I get the cold part though mine has mostly been cold feet. Harder for me to avoid meals; I’m a highly visible exec :slight_smile:

(MLD) #108

That works well for breakfast and possibly lunch but it would be very difficult to do at business dinners with a lot of protocol and such. Many trips are not that way but some are.

I finished the fast on Saturday, took it easy on Sunday and ate normally last evening. Moving right into IF. We’ll see how it goes.

Thanks for the good wishes and the same/best to you (and everyone here)!

(Camille Yeager) #109

I’ve seen the science for both short term and long term, and I think there is a good chance that Phinney AND Fung are both correct, it just depends on how much body fat you have when you start out. I wish someone would go over to Russia and get those fasting records (thousands of long term fasts of over a week) and collate them. It would make a fascinating study, and help us understand the issue definitely.

(Scotty) #111

I know this is a revival of a pretty old discussion but I was reading through a lot of the older extended fasting material and saw this and I have what might be an interesting n=1 piece of information. About 2 years ago I decided to go in for a DEXA scan as I was about to start a new powerlifting training schedule and wanted to have a baseline. I visited with the DEXA consultant about proper preparation for the scan and they told me if I was keto that my lean mass would show up lower. I opted to go ahead and get the scan done while keto-adapted. I went back a few weeks later and had another one done carbed out and by comparison I had gained 13 lbs of “lean body mass” in just days. Basically it was the water in my muscles and liver that was bound with the glycogen. Never less, the DEXA saw it as muscle and I’m sure a bodpod or float tank would too. I say all this because it makes me wonder if the LBM loss that some studies say are lost during fasting is really just the “de-watering” of our muscles as we deplete glycogen.

As another aside I have completed several 5 day fasts as well as an 11 day fast with no perceptible loss in strength.

I'm not getting enough protein most days
(Doug) #112

Scotty, good post. Yes, water weight can make a big difference, and one can further ‘game’ the system by fasting and going really low on electrolytes to purposely dehydrate oneself - this will make the first DEXA scan show erroneously high on fat, then you do what you did - eat a lot of carbohydrates to gain all that water (and perhaps eat a lot of salt for further water retention). The swing between measurements would be stratospheric.

I always think of skin loss when ‘lean body mass’ comes up - skin makes up about one-sixth of our weight (a fact which continues to amaze me). Not much will change over a given fast, unless it’s of very long duration, but with substantial weight loss it grows in significance.

Of course we don’t lose skin as a linear percentage with weight loss. It can be figured with things like the Mosteller equation. I used this site: http://www.medcalc.com/body.html

It will vary slightly with one’s height, but the results from my plugged-in figures of a guy going down from 340 lbs or 155 kg show that a 25% weight loss means ~12% surface area loss. A 50% weight loss is ~25% less surface area. For our 340 lb guy, that’s a 7 or 14 lb loss in skin, assuming the extra skin goes away (certainly varies with the individual).

I think some of the “Oh no - I’ve lost LBM!” complaints is due to lost skin being mistaken for muscle.

While I grant that it indeed is possible to lose LBM, my opinion is that this fear is often overblown. My job is occasionally pretty physical, moving/lifting metal sets of steps, gas cylinders, etc. 100 to 150 lbs or 45-70 kg. I’ve fasted roughly 18 times during the past year, at least 3 days in length each time. I don’t lift weights and have done nothing as far as aerobic exercise during that time (to my shame).

I’m 59 years old and have lost 55 lbs. I can lift those things just as well as ever. Whatever LBM I’ve lost is no concern at all of mine.

(Todd Allen) #113

Could you still lift/move them as well while wearing a backpack with 55 lbs of bacon in it? My physical performance is much better than it was before I started losing weight although dexa scans suggest about 20% of my weight loss so far has been lean mass. As previously pointed out the dexa scans have limitations and it is hard to get precise figures. Personally, I think how we feel and perform are most important despite being unable to measure them numerically.

(Doug) #114

Wow, Todd - really gave me pause there - I guess not. I severely doubt I’m any stronger now, but having the fat distributed “all over” means a lot better balance than with the backpack, I’m thinking…?

I’m not sure what all to think here - even skin has a layer of fat in it, more developed in women than men - that’s why they are more rounded and smoother, more pretty than us more angular, jutting-out men. So skin loss is not going to be solely LBM loss. Water DEXA-scanned as muscle: probably, at times.

Do you think you’ve gained aerobic efficiency? That, for starters, would explain better physical performance, though not for short-term ‘grunt’ strength.

On lifting - I really don’t “have” to lift the gas cylinders. Could get other people to help, or use a crane, etc., but it’s quicker just to do it and there’s a measure of pride involved. It’s awkward, since it’s like hefting a rigid person standing next to you. Some are a little larger and/or have thicker steel walls; the maximum weight is 163 to 170 pounds (~75kg) - I just checked. It’s a good example for me because I could barely do it, as far back as I can remember. If I don’t have it balanced right, it’s not going to happen; I’ll have to put it down and try again. I’m sure I was stronger when I started this job at age 25, but even then I don’t remember it being much easier, if any. Lift the cylinder up on one shoulder, then put the bottom end of it on the floor of a trailer (as in tractor-trailer, so ~ 56" or 1.4 meters high) then stand the cylinder up.