Page 23 of 41 FirstFirst ... 13212223242533 ... LastLast
Results 221 to 230 of 404

Thread: Intermittent Fasting - A Primer ( Part 3 ) page 23

  1. #221
    BestBetter's Avatar
    BestBetter is offline Senior Member
    Join Date
    Nov 2011
    Location
    NY / Italy
    Posts
    1,210
    Shop Now
    If you've answered this question/discussed this already, let me know and I'll do some more digging to find it.

    Pklopp, you've given some VERY detailed and helpful physiological information on other threads, so I'm really curious to know what you think of:

    1) IFing and women, specifically
    2) IFing and IBS

    1) I am a women, early 30s, with very good muscle development and a few pounds of stubborn fat to lose. I IFed for months and never noticed any change in fat loss as a result. My standard was 8/16, though I frequently did 20 or 24 hour fasts, with an occasional 40 hour one thrown in for good measure. I recently read this article: http://www.paleoforwomen.com/shatter...he-literature/ which discusses how the very limited studies that did concentrate on females and IFing showed VASTLY different effects on the females, indicating that IFing was actually a stressor and did not produce the positive health benefits that it did in the males.

    Here is an excerpt:


    I was struck by what seemed like an egregious sex-based oversight in that MDA post I
    linked to above. MDA cites this article as a “great overview” of the health benefits of intermittent fasting.
    This startled me because the article MDA cited was for me one of the strongest proponents of sex-
    specific differences in response to fasting. This occurred in two striking areas: a) women in studies
    covered by the review did not experience increased insulin sensitivity with IF regimes and b) women
    actually experienced a decrease in glucose tolerance. These two phenomena mean that women’s
    metabolisms suffered from IF. The men’s metabolisms on the other hand improved with IF across the
    board. Recall that the review was reported by MDA as “a great overview of benefits [of IF].”

    2) Again, I am a big fan of IFing, but it contributed to making my IBS worse, because one of my triggers is eating too much at once. Even though I love the IDEA of eating one or two huge meals per day, and I was doing that daily for months, it gave me terrible pain. Going back to several smaller meals throughout the day made me feel better pretty immediately. Even now that I have mostly healed my IBS, I have to be very careful with meal size, because if I eat too much, I will definitely get abdominal pain.
    Last edited by BestBetter; 07-20-2012 at 08:45 AM.

  2. #222
    pklopp's Avatar
    pklopp is offline Senior Member
    Join Date
    Nov 2010
    Location
    London
    Posts
    529
    Quote Originally Posted by BestBetter View Post
    If you've answered this question/discussed this already, let me know and I'll do some more digging to find it.

    Pklopp, you've given some VERY detailed and helpful physiological information on other threads, so I'm really curious to know what you think of:

    1) IFing and women, specifically
    2) IFing and IBS

    Here is an excerpt:

    I was struck by what seemed like an egregious sex-based oversight in that MDA post I
    linked to above. MDA cites this article as a “great overview” of the health benefits of intermittent fasting.
    This startled me because the article MDA cited was for me one of the strongest proponents of sex-
    specific differences in response to fasting. This occurred in two striking areas: a) women in studies
    covered by the review did not experience increased insulin sensitivity with IF regimes and b) women
    actually experienced a decrease in glucose tolerance. These two phenomena mean that women’s
    metabolisms suffered from IF. The men’s metabolisms on the other hand improved with IF across the
    board. Recall that the review was reported by MDA as “a great overview of benefits [of IF].”
    Quite coincidentally, I recently posted something about the very study referred to in that excerpt in another thread here on MDA. I've included the salient bits here, so no need to go elsewhere to read it. Unfortunately, in general, we are both victims of the medical research literature, meaning that it is true that the preponderance of research seems to be male biased. As a result, it is difficult for me to address female specific issues because I lack the primary research from which to do so.

    With that said, it is my experience that bloggers tend to sensationalize research in an attempt to drum up followers. The excerpt you provided is fairly representative of this. I'm not going to address the animal studies cited, mostly because we would need to agree that rats and humans are equivalent, and I'm not prepared to do that. With respect to the human studies, though, as far as I can make out, the primary concern raised is with insulin sensitivity and glucose tolerance in women in response to IF:

    Quote Originally Posted by Paleo For Women(PFW)
    Heilbronn et al found that with IF insulin sensitivity improved in men (21 participants) but not in women (20 participants): after three weeks of alternate day fasting, insulin response to a test meal was reduced in men. Women experienced no significant change. “It is interesting that this effect on insulin sensitivity occurred only in male subjects,” they report. The IF regime, moreover, was not just neutral for women but was downright harmful, specifically with respect to glucose tolerance...
    Straight off the bat we have a problem because if you click through the link to get to the study, you'll notice immediately that PFW got some fairly basic things wrong, because that particular study had 16 total participants, 8 of each gender ( see the table below ), not 41 as the above quote would have it. Maybe PFW is confused and referring to another study, but it should make you raise an eyebrow, at least.

    Leaving that aside however, if we intend to make decisions based upon this study's results, the first thing we need to do is to make sure that the study participants were fairly representative of the general population. For instance, we wouldn't necessarily want to radically change our lifestyles based on studies where herbivorous animals were fed a carnivorous diet with resulting adverse effects.

    Let's take a look at some of the characteristics of the subjects from the Heilbronn et al study:



    A couple of things immediately strike me about this, and I've highlighted them above. First notice that the males in this study are pretty fat relative to the females, given that they have roughly the same body fat percentage, which is very unusual for the general population, as women tend to carry more body fat in interesting places ( for the most part )

    The second thing that jumps out is that the males have double the fasting insulin levels of the females, and yet, they have about the same blood glucose levels. In other words, relative to the women in this study, the men are significantly hyperinsulinemic. Given that this is the case, would we not expect a different response among the men and women to an ADF intervention? Would the results have been the same if the researchers had studied hyperinsulinemic men compared to hyperinsulinemic women? How about hyperinsulinemic men vs. normoinsulinemic men? Hyperinsulinemic women vs. normoinsulinemic women? If we want those questions answered, we'll need to do the studies ourselves, unfortunately.

    But setting all this aside, the research seems to suggest that the women cleared glucose less rapidly after the ADF regime. Why would this be the case? Well, one simple answer would be that they are adapted to oxidizing fat ( ketone adapted ) and are reserving glucose for tissues the depend on it for their survival. If this were the case, ketone oxidizing tissues would become physiologically insulin resistant, giving us the observed glucose tolerance results. This would have been a very simple thing to rule out by merely testing the subjects for ketones in the blood, but unfortunately these researchers did not do so.

    Animal studies ( for what they are worth ), on the other hand, found that ADF, as expected, caused a doubling of ketone bodies ( aceto-acetate and beta-hydroxy butyrate ) due to increased fatty acid oxidation:

    Also noted by Anson et al was a doubling of the plasma concentrations of beta-hydroxybutyrate in the ADF group but no change in the control group.
    Heibronn et al also did not control for several confounding factors, including neither the subject levels of physical activity, nor their diets:

    Subjects had different levels of physical activity, with seven being sedentary, three being moderately active (exercise one to two times per week), and six being quite active (exercise three or more times per week).
    It is well known that moderate activity is glycolytic in nature, which means that those subjects that were "quite active" would be glucose sponges. Since we are not told by the researchers who the "quite active" subjects were, if we were to assume that they were all male, that in and of itself would be enough to skew the glucose tolerance test.

    On each feasting day, subjects were informed that they could eat whatever they wished.
    So we don't know what the subjects ate when they weren't fasting. We don't know the caloric intake, the macronutrient breakdown, nor the meal timing ... all of which potentially play a role in glucose clearance rates. Note, for example that a carbohydrate heavy diet predisposes one to rapid glucose clearance whereas a fat heavy diet does the opposite.

    When all is said and done, there are significant problems with this study, far too many for any conclusion to be drawn. I would be extremely leery of basing any decision about IF on this "evidence."

    Lastly, an extremely important point that is glossed over by PFW is that this study employed an alternate day fasting protocol. So essentially, study participants would eat one day, but not the next. Even if we were to concede that this study's results were relevant, to claim that the ADF fasting protocol is equivalent and representative of the wide variety of approaches to intermittent fasting is disingenuous, if not downright intellectually dishonest. Consider that over the course of six days, participants would eat on three out of the six days. Were the ADF protocol to be replaced by three consecutive days of fasting , followed by three consecutive days of eating, it wouldn't surprise me if we would get different results. PFW, on the other hand, seems to believe that the two protocols would be equivalent.

    PFW goes on to reference another Heilbronn study which found beneficial benefits for both men and women resulting from ADF such as beneficial changes in HDL ( women only ) and triglyceride levels( men only ). So, both genders experienced benefits, but in different ways.

    I would certainly agree with PFW that it would be great if we had comparative studies of the effects of various fasting protocols on both men and women. I think the so called evidence that PFW cites in support of the assertion that fasting is unhealthy for women is drivel.


    Quote Originally Posted by BestBetter View Post
    2) Again, I am a big fan of IFing, but it contributed to making my IBS worse, because one of my triggers is eating too much at once. Even though I love the IDEA of eating one or two huge meals per day, and I was doing that daily for months, it gave me terrible pain. Going back to several smaller meals throughout the day made me feel better pretty immediately. Even now that I have mostly healed my IBS, I have to be very careful with meal size, because if I eat too much, I will definitely get abdominal pain.
    With respect to your IBS, please allow me to defer answering that until I get a bit more time.


    -PK
    Last edited by pklopp; 07-20-2012 at 07:19 PM.
    My blog : cogitoergoedo.com

    Interested in Intermittent Fasting? This might help: part 1, part 2, part 3.

  3. #223
    BestBetter's Avatar
    BestBetter is offline Senior Member
    Join Date
    Nov 2011
    Location
    NY / Italy
    Posts
    1,210
    Wow, as always, you never fail to impress! I read your response quickly, because I don't have much time right now, but I plan to re-read it a few times later today when I have some time to dedicate to understanding everything you explained.

  4. #224
    pklopp's Avatar
    pklopp is offline Senior Member
    Join Date
    Nov 2010
    Location
    London
    Posts
    529
    Quote Originally Posted by dommers View Post
    How do you feel about taking bcaas even when not training during the fast. Do you think it would mess up the normal process of fasting and how your body responds to it?
    I think BCAAs are pretty much a non-issue, assuming that you don't overdose on them, something which is pretty hard to do, as they taste absolutely awful.

    BCAAs seem to promote mitochondrial health and protein synthesis in muscle tissue, so there is an argument to be made for taking them. I believe that Martin at Leangains promotes something on the order of 20g BCAAs on lifting days, 10g before working out and 10g afterwards. Even if BCAAs were to be gram for gram converted into straight up glucose with 4 kcal/g energy density, and ignoring the energy costs of gluconeogenesis, then this would represent an 80 calorie carbohydrate "meal", a trivial amount.

    I would say take your BCAAs. At worst, you would be merely wasting your money, I don't think they would be harmful to your fasts or metabolism in general, and I'll continue under this assumption until I see some research suggesting otherwise.

    -PK
    My blog : cogitoergoedo.com

    Interested in Intermittent Fasting? This might help: part 1, part 2, part 3.

  5. #225
    Inksplat's Avatar
    Inksplat is offline Member
    Join Date
    Jul 2012
    Location
    Baltimore, MD
    Posts
    69
    So, here's my current dilemma.

    With a 5 hour eating window, if I eat at the beginning..I'm just not hungry against by the end.

    Today, for instance. I ate a bowl of the Primal Texas Chili at 1pm. Now, at 6:22, I'm staring at more food that I've hardly touched, totally uninterested.

    But I know that one bowl from early was only 3/4lbs of meat, so I'm looking at probably like 700 calories.

    I just can't get myself to eat anything else. And its good food I've got in front of me, totally tasty. But I look at it.. and I'm just "bleh."

    I'm just getting kind of concerned that I'm not eating enough, because I seem to be hitting around 800-1000 calories a day, as a 6'2", 315lb 27-year old male. I take some multi-vitamins, and some coconut oil..but that seems like way too little if just on the micronutrient side, though protein worries me too.

    But I am just not hungry.

    And I feel bad eating more just because I "know I should", because that feels like totally the opposite to what I should be doing. If I can look at food and not want it, then I definitely shouldn't be eating it.

    But the calories I'm getting are ridiculously low.
    SW: 324.6 ----- CW: 310
    Primal Journal

  6. #226
    BestBetter's Avatar
    BestBetter is offline Senior Member
    Join Date
    Nov 2011
    Location
    NY / Italy
    Posts
    1,210
    Okay, reread your reply several times, and I really appreciate the time and detail you put into it! Excellent analysis.

    I've got another fasting-related question/theory I'd love to hear your take on.

    My husband came up with a theory that my adrenergic receptors might be downregulated. I'm wondering if this is something that
    1) Is likely, given the evidence/symptoms
    2) Can be tested
    3) If true, can be reversed using beta blockers (or some other method)

    Here's the situation (and how it relates to fasting):

    1) I had been IFing for months with ease. Standard was 8/16, but often did 24 hour dinner-to-dinner fasts (and a few 40 hour fasts) with no hunger issues. When my IBS started flaring really bad and frequently, I decided to try an extended fast to give my digestive system time to heal. My original intent was to fast 3-5 days. However, once I hit the 48 hour mark, my normally low (60) pulse dropped into the 40s, I started getting arrythmias, and my normal lowish BP (100/65) dropped low (86/58). I tried taking electrolytes, coconut oil, and bone broth, but these things had no effect. My vital signs didn't normalize until I had sugar (fruit and honey). Then, I was fine.

    I repeated this fasting attempt, and always between the 24-48 period the same thing happened. Now, my vitals seem to drop super low once I hit the 24 hour mark.

    2) Things that are supposed to be stimulating don't have that effect on me. For example, i have a rx for both Dexedrine and Adderall (which I take VERY sparingly, perhaps 2x/month, so there's no possibilty I have a tolerance.) Neither of them suppress my appetite OR raise my pulse or BP. In fact, I recently took 20 mg of Dexedrine and there wasn't even a slight increase in pulse or BP. Similarly, caffeine has no effect on me.

    3) I had my cortisol tested a year ago, and it was slightly high, so I know I'm producing plenty of cortisol.

    4) i have a history of chronic stress (I'm assuming this could lead to the downregulation of receptors)

    5) I have chronic fatigue that isn't related to lack of sleep or diet (I've experimented with every combination of fats/protein/carbs, including some very high sugar/carb days) or supplementation that is supposed to improve CFS (d-Ribose, L-Acetyl-Carnitine, Co Q10).

    It was my body's response that to extended fasting that prompted the downregulation theory, because it really seems like my body just isn't able to mobilize the stored fat I've got; it really seems like my body is beginning a shutting-down conservation process rather than accessing adipose tissue, and it's my understanding that adrenaline is key in this process. However, if my receptors are downregulated, that might explain why the adrenaline can't get the job done (right?)

    If this is the case,
    1) Do you think beta blockers could upregulate the receptors (I'm a little hesitant to try this because my normal BP is around 95/60, which means either I'm already to low for beta blockers to affect my BP, or I could send myself into cardiac arrest).

    2) Do you think IF is a good idea for me/someone responding the way that I do.

    As I mentioned in a previous post, due to my IBS issues, I now tend to eat small meals, but I sometimes still try to keep them in an 8-10 hour window, so it's still technically IF.

    I'm very interested to hear your take on this!
    Last edited by BestBetter; 07-21-2012 at 03:42 PM.

  7. #227
    Neckhammer's Avatar
    Neckhammer is offline Senior Member
    Join Date
    Nov 2011
    Posts
    7,731
    Quote Originally Posted by dommers View Post
    How do you feel about taking bcaas even when not training during the fast. Do you think it would mess up the normal process of fasting and how your body responds to it?
    BTW I think this is a spam bot repeater....correct me if I'm wrong.

  8. #228
    Neckhammer's Avatar
    Neckhammer is offline Senior Member
    Join Date
    Nov 2011
    Posts
    7,731
    Quote Originally Posted by Inksplat View Post
    But the calories I'm getting are ridiculously low.
    How many days in a row have they stayed this low? I'm 5'9 and 165. I easily hit 2000 calories with my single meals, but I always use fatty meat and am very liberal with butter both to cook and on my meal.

  9. #229
    Inksplat's Avatar
    Inksplat is offline Member
    Join Date
    Jul 2012
    Location
    Baltimore, MD
    Posts
    69
    I rise and fall a bit. Some days I do manage to eat more, but I don't think I hit 2k very often. I used ghee to cook in, but I never really factor those calories in. I also take about 150-400 calories worth of coconut oil a day, but I do try and factor that in.

    I eat mostly meat, so its not like I'm stuffing myself with leafy greens or anything. I just fill up on a meal of 800-1100 calories, and then don't really get hungry again. This hasn't been going on for too long, but its still something I wonder about.

    I mean, with 315 pounds on me, I've got plenty of fat to burn. But I even worked out between these two meals today, and still I'm not hungry. If it wasn't for worry of getting enough protein, I'd probably be thrilled to be able to only eat 1000 calories and be full. That's like a dieter's dream. But I also don't want to lose a whole heap of of muscle.

    Though, after watching...I forget the name. That documentary about Juicing. He did it for 90 days and lost waaaay more fat than muscle, but still a considerable amount. I mean, I'm sure my appetite will kick back in once I've got less fat, but still. I'd like to get stronger during the process.

    I feel like my only alternative is to force myself to down a protein shake, but all the powders I find have soy and taurine and junk, so that doesn't seem like the best option.
    SW: 324.6 ----- CW: 310
    Primal Journal

  10. #230
    Neckhammer's Avatar
    Neckhammer is offline Senior Member
    Join Date
    Nov 2011
    Posts
    7,731
    Inksplat...to put it into perspective as to how much protein you need what do you approximate your lean mass to being at this time?

    And those things you say you don't count do actually count . So 1100 + your call it 4-600 worth of coconut oil and ghee gets you up to 1700 respectable calories.

    When I said I ate 2000+ with ease that was counting every bit of butter and cream that I use in cooking and to flavor.

Page 23 of 41 FirstFirst ... 13212223242533 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •