Magical thinking and fasting
I get eating one meal a day, no qualms from me on that. But long-term fasting? You do know that your body has to get protein from somewhere to repair itself. Also, that small amount of glucose you need to power parts of your brain comes from protein, so it will tear down muscle mass to get it.
I like much of what J. Fung says, but I think he is out-to-lunch, dangerously so, on fasting. http://www.theatlantic.com/health/a...ut-food/508220/ Also, remember "The Biggest Loser" effect? Extreme calorie deprivation/exercise led to severe and permanent reductions in metabolism. I'm just curious why you wouldn't think this would lead to the same situation. I'm thinking that people need to try to think critically about what he is saying and do some research. Don't just guzzle down the koolaid just because you like Dr. Fung. |
Nancy, I am not a long term faster. But my understanding of the phenomenon is that FASTING VS severe calorie reduction, gives a different result, metabolically.
That, and, of course, no one with a life can keep up the level of activity that participants in the Biggest Loser sustain during the course of the taping of the show. |
I'm beginning a 72 hour fast today. I will force my body to take it's protein requirements from the extra skin I grew when I blew up in size. And if I feel unwell at anytime I will eat some food and the fast will be over.
blew up, blowed up, this is the war zone :) Thanks for bringing the topic up Nancy! |
See, that's where I think the logic breaks down. Fasting is no different than severe calorie restriction except it is more extreme.
"Reducing food intake for weeks causes metabolism to slow, so that a person who once needed 2,000 calories per day to function might now need only 1,800. After the fast is over, it’s not clear whether the metabolism will bounce back. A recent study of contestants on The Biggest Loser, who cut their calorie intakes dramatically for the show, found the participants must now eat hundreds fewer calories each day than people of a similar size in order to maintain their reduced weights." So, I guess I'd want to see some studies that proved it wasn't the same. And I'd want to see these same studies replicated. Getting your metabolism slowed down by 15-30% permanently isn't fun. I'm not sure but if you do this over and over again, does it slow more each time? Quote:
Oh dear... I have no idea where your body is going to get it's protein requirements. It could be your heart, your liver, your left big toe. What on earth makes you believe it will be your extra skin? |
Dr Fung's own explanation of the difference is the subject of his most recent post on November 10.
https://intensivedietarymanagement....ing-fasting-27/ Though it is also helpful to read the previous 26 posts, Many charts and graphs did not copy below. The difference between calorie restriction and fasting – Fasting 27 Quote:
One point he probably does not repeat enough, and not in The Atlantic, is that his patient population for the most part are obese, very sick if they already have diabetic nephrology, and fast weight reduction is way better than dying on a dialysis machine. People who would like to lose ten pounds..or even thirty, should probably not consider extended fasts. Two days a week or the 16:8 day is more than adequate. Fasting for cancer treatment and other metabolic therapies is another reason fasting is making a comeback, but yet again, a very specific use for a sick population...not to lose a few pounds before the holidays. |
Man, I hope like hell he has valid citations for these claims. I also notice he mentions he does 2-day fasts, but yet he's advocating much, much longer fasts. Like I said, I think your body is probably okay for short fasts used for IF. At least you're getting some protein in for repairing it.
|
I wish there was a "like" button on posts, Janet...that was incredibly informative. :)
|
You don't have to look to far to understand the effects long-term fasting has on the body. It has been studied endlessly in hunger-strikers.
http://www.livescience.com/28984-hunger-strike.html "After the third day of a hunger strike, the body starts to use muscle protein to make glucose, a sugar that's needed for cell metabolism. Levels of important electrolytes, such as potassium, fall to dangerous levels. The body also loses fat and muscle mass." So, you're probably fine up until 3-days in. Remember how we talk about the various problems with LC flu and electrolytes? Well, it is also going to be an issue with fasting. Your body will have to tear down bone to get potassium and probably muscle to get other electrolytes. "Low levels of thiamine (vitamin B1) become a real risk after two or three weeks and can result in severe neurological problems, including cognitive impairment, vision loss and lack of motor skills." |
I added something to the post after the copy, repeating here since you were typing at same time:
One point he probably does not repeat enough, and not in The Atlantic, is that his patient population for the most part are obese, very sick if they already have diabetic nephrology, and fast weight reduction is way better than dying on a dialysis machine. People who would like to lose ten pounds..or even thirty, should probably not consider extended fasts. Two days a week or the 16:8 day is more than adequate. Fasting for cancer treatment and other metabolic therapies is another reason fasting is making a comeback, but again, a very specific use for a sick population...not to lose a few pounds before the holidays. The Obesity Code book has extensive citations for each chapter, I assume the new book does as well. Steve Phinney disagrees with him on the whole protein issue...says they use different studies to bolster their claims...but they both do have studies. :) |
From my reading of the book, Fung does not advocate extended water fasting for the general public. Bullet proof coffee and bone broths are a different animal.
|
Quote:
That was kind of tongue and cheek (both excellent protein sources by the way) I trust that my body will recycle protein from places that are non critical first. Also, it has been my experience that It's fairly easy to build muscle. The amount of total protein "loss" over the course of a few days is minute and probably good for you. These are just my uninformed opinions. However, I do agree, if you have no adequate fat supplies to support extended fasting than you probably shouldn't do it. I would consider extended fasting a length exceeding 3-5 days. More opinion, take it for what it's worth. I'm willing to admit I could be exactly WRONG and am willing to change if required. |
Fung also advises supplementing with a multivitamin/mineral if going beyond 2 or 3 days.
|
Those "hunger strikers" weren't fasting because they were being force-fed. Ancel Keys' Minnesota "starvation" studies students also weren't fasting, they were on low calorie diets. None of these people were allowed to become fat adapted, where one can actually make glucose from fat. http://chrismasterjohnphd.com/2012/...ose-from-fatty/
If you get force-fed through the nose or are fed 500-1000 calories of SAD in a ward study, you will never become fat adapted, so you will use up all your blood glucose, then glycogen, then use protein to make glucose. From some of the cited articles in Fung's books, true fasting with zero or close to zero carbs, kicks in other body-saving pathways like increasing human growth hormone production on day 2-3 and reducing insulin resistance. This amps up autophagy where the body breaks down decrepit cells but conserves and reuses pieces to build new protein molecules (moreso than when you are eating protein so the body doesn't bother to conserve it). Fasters who have been closely monitored don't lose muscle until they get below 4% body fat. In fact, some gained a pound or two of lean body mass during 30-90 day fasts. |
No, not all hunger strikers are force-fed. Force-feeding is very controversial. If they were force-fed, they wouldn't be showing the effects of starvation. The article I linked was specifically about hunger-strikers that were allowed to starve and what happens to them during the course of their hunger strike.
Specifically the article I cited says: Quote:
|
I'm comfortable with longer fasts and have done very well with them. In this case, I'm talking up to 96-hour fasts (4 days) where I've consumed only water, tea, salt. I felt great and could have gone longer. For fuel for the brain, very little glucose is required, and one's fat reserves provide the ingredients for the necessary fuel the body requires. There are still camps arguing energetically regarding how the body derives fuel from lean mass or fat mass, and my readings of the science indicates that the body is very protective when exogenous food sources are completely eliminated by compensating with HGH and ketone bodies. Don't forget that the glycerol backbone of fat contributes to the production of the small amount of glucose the body needs via gluconeogenesis. Yes, energy can come from fat or protein. For me, I don't believe I've ever been that low on body fat where fasting would require my metabolism to get glucose from lean mass protein.
Here's a very good Ted talk from Mark Mattson explaining the benefits of fasting. If the root of the argument here is the danger of long fasts, I believe that a lot remains to be learned here, and we really need a definition of "long fasts." https://www.youtube.com/watch?v=4Uk...eature=youtu.be Good dialog and discussion on this thread! |
All times are GMT -6. The time now is 23:57. |
Copyright © 2000-2024 Active Low-Carber Forums @ forum.lowcarber.org
Powered by: vBulletin, Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.