14-Day Fast?

I'm wondering if anyone here has any experience with fasts of a longer duration. I do IF and have done 7-8 days of fasting in the past, but I was reading Dr. Jason Fung's book on fasting and he outlines the usage of longer fasts (7-14 days) for curing diabetes, kickstarting weightloss and dramatically improving insulin resistance. I'm not diabetic but I'm overweight and likely at least pre-diabetic, if not quite insulin resistant. I'm also in a unique position where I work at home and have no real commitments this month. He recommends a daily multivitamin for fasts this long, and I can grab trace mineral drops to keep my electrolytes up throughout. Spring water, black coffee, plain tea. He discusses using small amounts of fat (heavy cream in coffee, coconut oil, bone broth) but I think I'll probably stick to plain, non-caloric liquids if I go through with this.

Wondering what you guys think of this. Is anyone familiar with Dr. Fung's work? With lengthy fasts? Anything I should look out for? Is it dumb and reckless?

RedComet wrote:I'm wondering if anyone here has any experience with fasts of a longer duration. I do IF and have done 7-8 days of fasting in the past, but I was reading Dr. Jason Fung's book on fasting and he outlines the usage of longer fasts (7-14 days) for curing diabetes, kickstarting weightloss and dramatically improving insulin resistance. I'm not diabetic but I'm overweight and likely at least pre-diabetic, if not quite insulin resistant. I'm also in a unique position where I work at home and have no real commitments this month. He recommends a daily multivitamin for fasts this long, and I can grab trace mineral drops to keep my electrolytes up throughout. Spring water, black coffee, plain tea. He discusses using small amounts of fat (heavy cream in coffee, coconut oil, bone broth) but I think I'll probably stick to plain, non-caloric liquids if I go through with this.

Wondering what you guys think of this. Is anyone familiar with Dr. Fung's work? With lengthy fasts? Anything I should look out for? Is it dumb and reckless?

“Likely at least pre-diabetic, if not quite insulin resistant”? Don’t you think you should have a complete physical before embarking on this dramatic step? I suggest you put down Dr Fung and pick-up Primal Blueprint. Forget fasting. Focus on eating whole nutritious foods along with mental and physical exercise. To answer your question, yes, your plan is dumb and reckless.

There are others more familiar with dr. Fung's work and fasting long term that will no doubt reply to this as soon as they notice it.

However, my main concern would indeed be the lack of supervision by someone knowing what to focus upon, keeping an eye on you during the fast.

He recommends a daily multivitamin for fasts this long, and I can grab trace mineral drops to keep my electrolytes up throughout. Spring water, black coffee, plain tea. He discusses using small amounts of fat (heavy cream in coffee, coconut oil, bone broth) but I think I'll probably stick to plain, non-caloric liquids if I go through with this.

What's your reasoning for skipping bone broth and such? Faster results? Autophagy should happen regardless. Which offers the next question: why fasting and not keto?

I read and liked the book very much, but haven't any experience with a fast of that length. As I recall, he [Fung] considers fasts of 48-72 hours to be quite routine and completely safe, but does suggest some oversight for longer fasts. Hydration and electrolyte balance are the crucial elements, oh, and don't go bonkers with exercise.

This seems excessive for someone who is merely "overweight" and "likely at least pre-diabetic." It doesn't sound like you know what your average blood glucose levels are, which would be necessary to make such a self-diagnosis. In any case, pre-diabetes can often be corrected without resorting to such extremes.

If you want to shift your metabolism over to "fat burning," eating keto will do the trick. Keto + IF or shorter duration fasts (3-5 days) would speed things up. If you're looking for autophagy, I'm pretty sure I heard Fung say in one podcast or another that multiple shorter fasts will ultimately achieve the same results as less frequent but longer fasts.

Like you could go nuts and fast for 30 days, or do 4-day fasts every month for a year, and in the end (assuming you don't have a very specific health challenge like cancer or autoimmunity) it's more or less the same.

With the limited info you've provided, I would stick to keto and IF/shorter fasts if I were in your shoes. This allows you to still put in hard workouts and build muscle, which would be impossible during longer fasts.

Jason Fung is un-scientific at best, and he is a science denier at worst. I would stay away.

ekba wrote:Jason Fung is un-scientific at best, and he is a science denier at worst. I would stay away.

That is being quite generous. I would say Fung makes Mercola look legit.

I think Nightly Orange has some valid points. It would warrant getting your blood glucose checked first. Thinking you have high blood glucose levels and knowing it are quite different. Make an appointment with you GP and get it tested. Or, see if a friend or family member has a home glucose monitoring device and borrow it for a day or two and do multiple readings. I recently felt like my sugars might be whacky and tested for a few days. Turns out my blood glucose is actually right about perfect. In the end I discovered it was actually estrogen surges that were causing me to feel like my blood sugar was off. My point is that symptoms can often be unreliable indicators of health. It's better to know than guess.

I have never fasted as long as you propose so I have no first-hand knowledge but it seems extreme to me. There are better ways as members have suggested above.

If you do go ahead with this you will definitely need to report back with your experience and insights and results.

A prolonged fast will create a large calorie deficit. That's why you would lose weight. There are any number of less drastic ways to create a calorie deficit that don't risk cardiac atrophy and electrolyte emergencies. There is no magic. Stop hoping for a magical cure.

Don't keep us in suspense any longer RedComet... what have you decided to do? And why?

You've asked for opinions and that's what you got. As you can tell pretty much everyone answers based on their personal bias, which is understandable.

Yes. RedComet....inquiring minds want to know.....

I’ll weigh in as in favor of fasting in a general sense. I’ve not done or overseen anyone while doing more than 7 days. Many of your metabolic and immunological benefits occur in the 3-5 day range. More than that is obviously going to continue fat loss. That certainly is a good thing for metabolic derangement , but you do increase risk as well (although the risk is admittedly small). If you get to feeling poorly simply end the fast. And I would not make extended fasts a frequent event.

I’ve read Fungs first book. Much of it was rehashing the science and protocols many who delve into IF are already familiar with. Lean mass sparing, fat burning, autophagy, improved insulin sensitivity....etc. I’m not sure where folks get that he’s a science denier? Is there anything in his old or new book that you find to be false which you could point to?

Lovebird wrote:Don't keep us in suspense any longer RedComet... what have you decided to do? And why?

Sorry, lol. Didn't mean to leave everyone hanging. Ultimately decided not to go through with a longer fast. Settled on doing IF, instead. One meal a day. I'm eating lower carb than before, but not keto. Might make the switch to full keto in the future, but I'm not a huge fan of going too low carb. Seems like it'll be more sustainable for the long term, and long term changes are really what I should be looking for. I've been at it for about a week now and have had some good results. Already tightening my belt an extra notch and feeling good.

Despite how I made it sound in the OP, I'm not completely clueless about the state of my health. In the past, I have experimented with glucometers, and while my blood sugars aren't totally insane and I have no symptoms of diabetes, I know for a fact that my doctor--a pretty conventional dude who loves over-prescribing--would start chatting with me about the potential for diabetes meds down the road if I bothered to go see him. Diabetes runs on both sides of my family, too, thus the concern.

My interest in the longer fast stemmed from a few places. Faster results, sure, but also I'd hoped that a longer fast might help me reset my appetite and improve my relationship with food. Perhaps it would've, or maybe it would've backfired spectacularly. Most of the benefits are attainable through IF, though, and frankly it's a lot less work to just eat one meal a day, so I decided to do that. lol

Once I'm well-established with my IFing, I think I'll definitely try for a 3-5 day water fast for the immune benefits, though.

Curious why some people don't like Fung's work? I liked the book, though it was mostly regurgitated info.

RedComet wrote:

Curious why some people don't like Fung's work? I liked the book, though it was mostly regurgitated info.

Let’s start with this gem from his blog:

“The human body is not an isolated system. Energy comes in and goes out all the time. It is an open system so therefore thermodynamics does not apply in any manner.”

Really Dr. Fung? You just failed freshman physics.

^ Skewered him right there.

LOL I had never seen that quote from Dr. Fung... that is Thermodynamics 101 failed right there. But I think in his defence he is and M.D. and many M.D.s I know don't understand physics at all. He could have said "the human body us a complex system, so saying that calories in = calories out is an oversimification of the matter. This does not negate the laws of thermodynamics"

I do believe that his protocol works though. But not bc. thermodynamics doesn't...

P.S. I wouldn't do more than a 3-5 day fast without medical supervision.

I'd be hesitant to follow dietary advice from someone who has no concept of thermodynamics. It's not like your body engages in a complex set of chemical and biological reactions all day, everyday and the processing of the solids and liquids you consume have any thermodynamic implications.
I'm not familiar enough with Fung to know if he really falls in this category or not. The quote Ekba posted certainly makes it seem so.

I'm not sure Fung even cares. He wants to tap into the low-carb market, and "calories don't matter" is a common line with that crowd.

As for what works, fasting will cause weight loss because it is hypocaloric. If you can find some hypercaloric fasting protocol that isn't an oxymoron and still causes weight loss, I'd be fascinated to read about it. Molten lava fasting? The pounds just melt away!

I must jump to the defense of Jason Fung. I've been following him for quite a while, reading his blog and books, and I happen to think he is quite brilliant. I hate to see him smeared with one short passage that is taken completely out of context. What he is saying is that to apply the laws of thermodynamics only (the basis of calories in=calories out), is really a gross oversimplification of what happens in humans, and that is why CICO is not adequate to completely explain why people gain or lose weight. Way too many other variables involved in human metabolism.

I would encourage anyone who is interested to read his blog, some really interesting stuff. It is true that he was not great at written communication in the past-- I'm not thrilled with the book The Obesity Code, but his writing style has improved tremendously over the past few years (or he's getting a lot more help!). The downside of this is that his very funny, often inflammatory sense of humor has been toned down a lot, and I miss that. The Complete Guide to Fasting is an excellent book.

Personally I have incorporated intermittent fasting into my lifestyle, and feel that it is a very valuable tool for both health and keeping weight down. I don't feel a strong need to try a longer fast, just a bit of curiosity, and it will probably take more than that to push me to make the effort. For Red Comet and anyone who is concerned about blood sugar levels, I would highly encourage you to get an A1c test done. There are home test kits available, but they are tricky, so probably best to get it done by a lab. This will tell you a lot about the state of your blood sugar/insulin system.

I honestly don't think my Drs understanding of thermodynamics is that important either... and i find that Jason Fung understand metabolism probably a lot better than most people, and seem to have been able to save a lot of his patients (most of whom can't afford a primal diet), from the most serious consequences of their lifestyle....

I'm no defender of Dr. Fung and certainly no defender of long term fasts. However, I take issue with the attack just made against him stating he failed Physics 101. The proponents of "calories in calories out" often cite the laws of thermodynamics to support this view while FORGETTING that the same laws clearly distinguish between the actions within "isolated" and "open" systems. If Fung was accurately quoted, then he made an error by saying the "laws don't apply" but was accurate in the statement that the human body is an "open" system. Therefore, the portion of the laws of thermodynamics that apply, are the ones that govern an "open" system rather than an "isolated" system. Therefore, CICO (calories in calories out) is a faulty approach that ultimately fails if one is counting calories without regard to source within the environment they live.

Insulin is not the cause of obesity. Fung has his head up his ass. Obese people usually have high insulin, but you shouldn't mistake a sign for the thing itself. A negative energy balance is the way to lose fat, and losing enough fat will make your insulin work as it should.

sharperhawk wrote:Insulin is not the cause of obesity. Fung has his head up his ass. Obese people usually have high insulin, but you shouldn't mistake a sign for the thing itself. A negative energy balance is the way to lose fat, and losing enough fat will make your insulin work as it should.

I agree with this.* My PCP calls me Type2D, but a lot of doctors would call me prediabetic. She tried to put me on Metformin, and my A1C went down .1. When I told her I wouldn't take it anymore, but I would Paleo and walk every day, my A1C went down a whole point. And I wasn't even 100%ing Paleo.

*Except I don't know if this Fung-guy has his head up his ass. It seems like an uncomfortable position.

LoonieJ wrote:
*Except I don't know if this Fung-guy has his head up his ass. It seems like an uncomfortable position.

I don't know. A lot of smart people appear to enjoy the position.