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Leptin, am I missing something?

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  • Leptin, am I missing something?



    I dedicated today to researching leptin, and I am yet to find an answer to my question:


    If low carb dieters are so low on the hormone leptin, thus inhibiting fat loss, then how do low carb tribes such as the Eskimos get along just fine? Or how did the primal ancestors get along just fine?


    On top of that question:


    Is sugar the only contributing factor to cause fat cells to produce leptin?


    Any links, books, whatever... will help. Im tackling leptin this weekend. I also asked Mark to do a piece on it, so hopefully that comes through.

    sigpic
    In Pursuit of Healthiness, Only to Achieve Happiness!: www.livingnotsurviving.com

  • #2
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    I could be wrong, but here's how I understand it so far, based on reading Rosedale's book and Stephan's blog. I welcome criticism!


    Low carbers at normal body fat % don't have zero leptin, they just have lower leptin. Leptin levels cycle over the course of the day. Their brains are sensitive to circulating leptin. The amount of leptin present allows enough fat utilization for energy needs, and enough fat storage to replenish fat as needed. Everything stays in balance.


    Low carbers at higher body fat % do NOT have low leptin levels, though the level may be quite a bit lower than when they were eating high carb. Their fat cells are still signaling that there's plenty of fat stored. A low carb diet will hopefully lower leptin levels enough to restore brain sensitivity to leptin. This, along with lower insulin levels, allows the individual to shift the balance from net fat storage to net fat loss.


    A recent visitor here, awriter, believes that dietary manipulation cannot reverse leptin resistance in the hypothalamus. I haven't yet joined her yahoogroup to investigate further. However, Dr. Rosedale disagrees. He believes that dietary intervention effectively restores leptin sensitivity, though it will be slower and less effective as you get older (and presumably, more damaged).


    Edited to add: Rosedale's diet is low carb, high fat (ideally from nuts, avocados, fish, olives), and moderate protein (somewhat lower than Mark's recs).

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    • #3
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      And regarding your second question, leptin synthesis and secretion are correlated with total fat mass, insulin levels, and the movement/metabolism of glucose in adipocytes. Other hormones exert smaller effects as well.

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      • #4
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        Thanks for the info... Just read through a lot of Lyle McDonald's stuff on leptin, very interesting.


        Out of curiosity I did a 150gram carb refeed over 5 hours a couple days ago. I kept fat low and protein pretty normal... Seem to have better definition these past couple of days.


        I usually get this "hunger" feeling roughly every 7-10 days of low carb/primal eating where normal primal can't satisfy it. That's when I eat carbs and the feeling seems to go away. I think Im going to start doing it more strategically and see how it helps with hunger and body recomposition.

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        In Pursuit of Healthiness, Only to Achieve Happiness!: www.livingnotsurviving.com

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        • #5
          1



          Thanks for pointing me to Lyle's articles. It's interesting to read about how leptin acts and how it may be manipulated when trying to push body fat % down below the body's comfort zone. It is also fascinating to consider the male/female differences in leptin & insulin signaling and response.


          I can see why a bodybuilder might want to overrule leptin signaling in order to get down to single digit body fat, but from a Primal/paleo point of view I wonder how wise that is.... ;-)

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          • #6
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            If I understand leptins correctly, I don't think there is anything really too wrong with having low leptin levels, so eskimo tribes and our ancestors probably did just fine... i mean low leptin levels aren't a bad thing,.. are they? I mean, it is if you're trying to lose fat and you're on a plateau,.. but i don't think our ancestors weren't really concerned with fat loss and the same for eskimo tribes...

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            • #7
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              To a point, low leptin is fine, probably even healthy (see link below). But anything can be taken too far. Somewhere between a BMI* of 14 and 17, perhaps even a little higher for men, leptin seems to reach its lower limit. And when leptin levels are as low as they can possibly go, your body is starving. Your body doesn't like to starve. All sorts of bad things happen when you starve.


              http://wholehealthsource.blogspot.com/2008/08/cardiovascular-risk-factors-on-kitava_20.html


              * I wonder if the lower limit of leptin could be reached at a much higher BMI in bodybuilders, as their high muscle mass inflates BMI....

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              • #8
                1



                Well from what I've read low leptin levels is bad regardless of whether you want to lose fat or not, because leptin is a master hormone that regulates thyroid, adrenals, fat (which is pretty much an organ), and thus has an effect on other hormones.

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                In Pursuit of Healthiness, Only to Achieve Happiness!: www.livingnotsurviving.com

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                • #9
                  1



                  I think the key is to realize that one cannot isolate any single hormone as being responsible for any single process. Our hormones act in concert with each other, some doing double or multiple duties antagonistically and/or protagonistically with each other.


                  In other words, leptin does not work alone. Nephropal discusses how leptin is not the only adipokine (fat hormone) and I can't remember who posted this link in another thread (chima_p maybe?).


                  http://sparkofreason.blogspot.com/20...ck-in-asp.html


                  It discusses some of the complex ways in which fat is release from adipose tissue.


                  I for one am yet unable to grasp the complexity of our hormones but feel certain that they are the keys to health and longevity.

                  “It is a truism that almost any sect, cult, or religion will legislate its creeds into law if it acquires the political power to do so, and will follow it by suppressing opposition, subverting all education to seize early the minds of the young, and by killing, locking up, or driving underground all heretics.”
                  —Robert A. Heinlein

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                  • #10
                    1



                    From my basic understanding, the only way to get dangerously low levels of leptin is to have dangerously low levels of body fat, and to do that you need to be in chronic low energy balance, basically starvation.


                    Our ancestors wouldn't have been in this situation too much of the time and would have avoided the problems, thanks to Grok's propensity to eat anything edible he found.


                    Pikaia, It is possible to get very low leptin at pretty much arbitrary BMIs.

                    BMI is a poor measure of anything, with the key exception being an individual's weight in kilograms divided by their height in meters squared.

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                    • #11
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                      @ Greg B, yes I realize that. My point is that someone whose BMI is well above 17 can't assume that leptin levels aren't already way too low.


                      On a bodybuilding forum this might be irrelevant, because body composition might be the highest priority. One might choose to do refeedings as McDonald suggested in order to trick the brain into believing it would be safe to burn more fat.


                      But from the Primal Blueprint perspective, it seems that health considerations should always come before body composition goals. Refeeding in order to try to force BF down below 10% (or some other arbitrary number) is probably not the healthiest choice, no matter how nice it looks in the mirror. And yet I often see posters here looking for advice on how to "break a plateau" and lower an already exemplary BF%. Wisdom of the body, anyone?

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                      • #12
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                        I did a lot of reading on it and decided to just sum up a few basic consistent points:


                        -leptin is very important, but its still key to realize it plays a ROLE in fat maintenance/burning and appetite along with many other hormones


                        -leptin receptors found virtually everywhere in the body


                        -leptin is secreted by fat as far as we know, and fat is most definitely an organ on its' own, secreting many more important enzymes/hormones


                        -women tend to have 2-3 times more leptin then men at any given bf, could be due to their ability or need to become pregnant at any time


                        -Leptin levels may drop up to 50 percent in just 1 week of low calorie/low carb, do not raise in the same manner


                        -while glucose is high, leptin tends to be high (in most cases), also more bodyfat means more circulating leptin


                        -lowered levels of leptin correlates with lowered levels Follicle Stimulating Hormone (FSH) and leutenizing hormone (LH), also Thyroid Stimulating Hormone (TSH), simply said could lead to lowered sex hormones production and lowered thyroid functioning


                        Looking into leptin, many other hormones came up, and the one common denominator that lowered all these hormones was low calories. With that said, it is important to take calories into consideration when losing that last bit of fat, and revealing your abs. This happens with strategic planning of macronutrients, and manipulation of hormones (not in everyone of course).


                        On top of that, doing low carb does not mean you will have low leptin levels for sure. Some people will react differently, it's just something to take into consideration when you have stalled out for a couple months. This does not defeat the fact that most people have reported excellent/lie-changing improvements from the primal plan.

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                        In Pursuit of Healthiness, Only to Achieve Happiness!: www.livingnotsurviving.com

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                        • #13
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                          Thanks for the summary.


                          I guess one thing that could be said is that our bodies (via our hormones) are very well equiped to deal with variety and in fact may well thrive on it.


                          "Variety is the spice of life" as they say.

                          “It is a truism that almost any sect, cult, or religion will legislate its creeds into law if it acquires the political power to do so, and will follow it by suppressing opposition, subverting all education to seize early the minds of the young, and by killing, locking up, or driving underground all heretics.”
                          —Robert A. Heinlein

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