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Thread: Alternate Day Fasting- Debate and Science

  1. #1
    Join Date
    Dec 2011
    Dallas/Fort Worth Texas

    Alternate Day Fasting- Debate and Science

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    This is the companion thread to Alternate day Fasting- Support and Chat.

    If you think the whole idea is questionable, throw up your comments here. If you want to talk about the details of the science, or talk about a study, likewise.

    The main gene affected by alternate day fasts is SIRT1(in humans, Sir2 in non-human animals). I think most people who IF would be interested in ADF, as the longer period of food restriction seems to do some interesting things in the area of cell repair. However, I am not much into debating the science(just reading it), so I will leave that for others.

  2. #2
    Join Date
    Jul 2012
    Delaware Valley
    DH heard some discussion of this on Reach MD. I keep meaning to go listen to the podcast, but haven't yet. I looked around on the web at primary research and read one paper that described SIRT1 up regulation at 6hrs, maximal expression (2x) at 18 hrs and then a drop at 72 hrs. I dont remeber if it was humans or mice. I didn't save the link since I was only curious. I'm not sure that we know what the impact of various levels of SIRT1 over time will be. Certainly eating as little as possible over as long a stretch as one can manage is more advantageous than 6-8 small meals a day.
    50yo, 5'3"
    CW-125, part calorie counting, part transition to primal
    GW- Goals are no longer weight-related

  3. #3
    Join Date
    Jan 2013
    Lexington Park, MD
    I did alternate day fasts (anywhere between 12 and 24 hour) for a while, though not so much lately. Need to get back in the saddle!

    What's the significance of SIRT1 upregulation? What does that do for me and will I know it's going on?


  4. #4
    Join Date
    Dec 2011
    Dallas/Fort Worth Texas
    Paraphrased from the book by Dr. Johnson:

    SIRT1 interferes with the action of BAX, which initiates cell death. This allows the cell time to repair damage.
    It reduces hunger.
    It reduces inflammation by inhibiting NF-kappaB proteins.
    It inhibits fat storage by 'turning off' the PPAR-gamma gene.

    As far as I can tell, you can only know it is going on by its effects or by a muscle biopsy-probably not something you want to do!

    If you go to the wiki page on SIRT1, they have a long list of studies at the bottom that you can read,.

  5. #5
    Paleobird's Avatar
    Paleobird Guest
    The only thing that makes me see this whole program as questionable is the blatant pimping of resveratrol all over Dr Johnson's website. That stuff has been shown to potentiate breast cancer and (like all other antioxidants) has failed to show any positive benefit in humans.

    Johnson makes it look as if resveratrol is an essential element to success with his plan.

    And this is a very interesting article for anyone believing unequivocally that promoting SIRT1 is the greatest thing around.

    The bottom line is that the jury is still very much out. It could be a cancer suppressor or a cancer promoter. We just don't know yet.
    Last edited by Paleobird; 03-27-2013 at 07:44 PM. Reason: add link

  6. #6
    Join Date
    Feb 2013
    I think it's very interesting what is happening with all the different flavors of intermittent fasting. I feel like each different WOE activates the program in a different way, or a different part of the program. The complete answers will only be found when we figure out what questions need to be asked.

  7. #7
    Join Date
    Mar 2012
    I'm very interested in this topic. After resisting IF for a couple of years, I have been fasting about 12 hours per day. It seems to have made a massive difference. E.g., fat has poured off. I'm interested in the research about various intervals of fasting have different effects. As you can guess from my signature, I have zero interest in going longer at a time without food unless someone gives me hard evidence that I will get significant benefits over what I am doing now.
    Ancestral Health Info - My blog about Primal and the general ancestral health movement. Site just remodeled using HTML5/CSS3 instead of Wordpress.

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  8. #8
    Paleobird's Avatar
    Paleobird Guest
    I think IFing and even longer fasts are terrific for overall health. But I think people should let the fasting come to them naturally rather than try to force it into any particular schedule.

    I tried doing the one meal a day warrior diet thing just before finding Primal and it was a total fail. Clock watching all day. Is it time yet? Let's see, what am I going to have for dinner? Everything! because it's going to be a long time until tomorrow night. It was just too crazy making.

    Then as I got into primal, I first tried skipping breakfast a la the bulletproof system but I would be starving by lunch (when I would be most likely to eat junk being out of the house) but then not really have much appetite in the evening when there was good food to be had. So I decided to eat breakfast and skip lunch instead. That worked really well for a long time.

    Then I just started cutting back breakfast to being just "a bite" instead of a meal like a glass of kefir or a piece of cheese. Now I'm down to my version of bulletproof Teeccino (with cococnut cream and MCT oil) for breakfast, and then one real meal at dinner.

    So I've come full circle back to the warrior diet. But I think my body went through some changes to be ready for this. I got my thyroid all healed up (post chemo), got my metabolic flexibility between carbs and ketones going, then got into steady state nutritional ketosis.

    Now I only eat once a day but it feels totally normal and unforced.

  9. #9
    Join Date
    Oct 2009
    I got involved with JUDDD (ADF) solely as a way to control my calories, and I read Dr. J's book--but it was quite a while ago. My memory is that the effects of the SIRT1 gene remain speculative, as research is still in the fruit fly stage and not with humans.

    That said, there's much evidence that restricting eating is healthy, and I've certainly experienced that, so I don't really worry about any 'benefits' from SIRT1.

    My focus is on eating Primal and not overeating.

  10. #10
    Join Date
    Jul 2012
    Birkenstocks & hairy arm pits.
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    The documentary Eat, Fast, and Live Longer is pretty interesting. Some science, some 'how it feels' stuff, and a neat little interview with the oldest man to ever finish a marathon (maybe). It was pulled from youtube for copyright reasons, but it can be found here: Eat, Fast & Live Longer HD - Video Dailymotion

    In the above documentary, blood work results were the same after either one 72 hour fast as they were after six weeks of eating normally 5 days a week and eating fewer than 500 calories the other two days.

    I've also done a tiny bit of reading about water fasts which in general should be done under supervision if more than a few days.

    There has also been some research showing that lab rats that are chronically underfed, but not starved, lived longer than rats fed in a regular way. However, the flip side of that is that while in general obesity will shorten your life, a body fat number of about 20 seems to increase longevity in humans rather than one that is very low.

    What never seems to be mentioned in any of these studies are genes. (Implied in the lab rat stuff because lab rats are practically clones of each other.) For eg. Jack Lalanne lived to 96. His brother also lived to his 90s, but I can't find anything on how the brother lived. So, did the brothers have similar lifestyles that let them live so long or did they have similar genes? Or maybe even a combination of both.

    Never in the history of humans has food been so available 24/7/365, and we're getting sick because of it. Even as short a time ago as the 1950s, to find munchies at say 3:AM, you would most likely have to live in a city and have access to an after hours club (although, of course you'd have something in the fridge also).

    Anyway, after my reading and watching, it seems to me that the occasional day of starvation is probably good for most people. Alternate day fasting probably gets the same results as the 5/2 plan in the video, maybe even faster.
    "Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine


    Who says back fat is a bad thing? Maybe on a hairy guy at the beach, but not on a crab.

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