Very-low-carbohydrate diets and preservation of muscle mass

Discussion in 'Food and nutrition' started by Roger Zoul, Jan 31, 2006.

  1. Roger Zoul

    Roger Zoul Guest

    Hot off the press! This is good stuff....

    http://www.nutritionandmetabolism.com/content/pdf/1743-7075-3-9.pdf

    Background
    I would like to compliment Noakes et al. on their well-controlled study
    comparing effects
    of different diets on body composition and cardiovascular risk [1]. The
    authors suggested
    that a very-low-carbohydrate diet (VLCARB) may not be associated with
    protein-sparing,
    because their dual-energy X-ray absorptiometry (DEXA) data indicated that
    both VLCARB
    and very-low-fat diet resulted in significantly more loss of lean mass than
    the highunsaturated
    fat diet. It should be noted, however, that DEXA provides a measure of lean
    soft tissue (LST), and the original notion that LST hydration is constant is
    not correct.
    Rather, LST hydration varies as a function of extra- and intracellular water
    distribution
    [16]. I feel it is very unlikely that the VLCARB group catabolized more
    muscle protein than
    the high-unsatured fat diet group. This commentary provides some basic
    information on
    metabolic adaptations that lead to sparing of muscle protein during a
    VLCARB, and
    reviews studies examining the effects of VLCARB interventions on body
    composition.
     
    Tags:


  2. Susan

    Susan Guest

    x-no-archive: yes

    Thanks, Roger, excellent reference.

    Susan

    Roger Zoul wrote:
    > Hot off the press! This is good stuff....
    >
    > http://www.nutritionandmetabolism.com/content/pdf/1743-7075-3-9.pdf
    >
    > Background
    > I would like to compliment Noakes et al. on their well-controlled study
    > comparing effects
    > of different diets on body composition and cardiovascular risk [1]. The
    > authors suggested
    > that a very-low-carbohydrate diet (VLCARB) may not be associated with
    > protein-sparing,
    > because their dual-energy X-ray absorptiometry (DEXA) data indicated that
    > both VLCARB
    > and very-low-fat diet resulted in significantly more loss of lean mass than
    > the highunsaturated
    > fat diet. It should be noted, however, that DEXA provides a measure of lean
    > soft tissue (LST), and the original notion that LST hydration is constant is
    > not correct.
    > Rather, LST hydration varies as a function of extra- and intracellular water
    > distribution
    > [16]. I feel it is very unlikely that the VLCARB group catabolized more
    > muscle protein than
    > the high-unsatured fat diet group. This commentary provides some basic
    > information on
    > metabolic adaptations that lead to sparing of muscle protein during a
    > VLCARB, and
    > reviews studies examining the effects of VLCARB interventions on body
    > composition.
    >
    >
     
  3. so what does this mean in english??
     
  4. [email protected] wrote:
    >
    > so what does this mean in english??


    Some stuff that I got out of it:

    1) Since they used the the acronym VLC they didn't test normal
    carb intakes for people following most LC plans. They appear
    to have used 20 or less so they are only testing Atkins Induction
    extension. The advantage is doing so is easy. The disadvantage
    is it says little about what is done by very many LCers and what
    is recommended by every single popular LC book.

    2) The fat loss on very low carb was about the same as the
    weight loss on very low fat when given the exact same total
    calories. Not encouraging to folks who want LC to work faster
    then LF, but the question becomes how low in fat did they have
    to go?

    3) No mention whatsoever of relative hunger reported by the
    subjects. Sometimes what's left out is interesting.

    4) They discuss differing water loss levels. Ah, so that's how
    LC beats LF. Better early water loss on low carb, no surprise
    there.

    5) They discuss methods for estimating lost lean using chemistry.
    So at least they are noticing that water loss differences occur,
    that fat loss happens on either low fat or low carb, and that
    both make it harder to measure lean loss.

    So it looks to me like their initial goal was to prove that LC
    causes more lean loss than LF, but the hard data failed to
    justify their iniial goal. As a result they used strange wording
    to hedge their bets.

    When studies fail to give the desired outcome that's what they
    read like. "Weasel words"
     
  5. Roger Zoul

    Roger Zoul Guest

    [email protected] wrote:
    :: so what does this mean in english??

    From the paper:

    "Conclusion
    Although more long-term studies are needed before a firm conclusion can be
    drawn, it
    appears, from most literature studied, that a VLCARB is, if anything,
    protective against
    muscle protein catabolism during energy restriction, provided that it
    contains adequate
    amounts of protein."

    Hence, if you get sufficient protein, you won't lose lots of muscle while
    losing weight on LC. Weight lifting will tend to help minimize muscle loss,
    too.
     
  6. Susan

    Susan Guest

    x-no-archive: yes

    Roger Zoul wrote:
    > [email protected] wrote:
    > :: so what does this mean in english??
    >
    > From the paper:
    >
    > "Conclusion
    > Although more long-term studies are needed before a firm conclusion can be
    > drawn, it
    > appears, from most literature studied, that a VLCARB is, if anything,
    > protective against
    > muscle protein catabolism during energy restriction, provided that it
    > contains adequate
    > amounts of protein."
    >
    > Hence, if you get sufficient protein, you won't lose lots of muscle while
    > losing weight on LC. Weight lifting will tend to help minimize muscle loss,
    > too.
    >
    >
    >


    8 weeks is too short to really point out the differences in LBM, because
    the water whoosh of the LC dieters is counted as LBM loss, if I'm not
    mistaken.

    Susan
     
  7. Roger Zoul

    Roger Zoul Guest

    Doug Freyburger wrote:
    :: [email protected] wrote:
    :::
    ::: so what does this mean in english??
    ::
    :: Some stuff that I got out of it:
    ::
    :: 1) Since they used the the acronym VLC they didn't test normal
    :: carb intakes for people following most LC plans. They appear
    :: to have used 20 or less so they are only testing Atkins Induction
    :: extension. The advantage is doing so is easy. The disadvantage
    :: is it says little about what is done by very many LCers and what
    :: is recommended by every single popular LC book.

    Which "they" are you referring to? Reference [1] in the paper concerning
    this post? It's kinda hard to put your comments in context without knowing.
    I think you're referring to the paper on "Comparison of isocaloric very low
    carb...." which is the topic of another post...

    According to my reader, catskills is asking about VLC and muscle loss. I
    think you'd agree with the comments made by that author (who disagrees with
    a statement made by the authors of the other paper which your comments here
    seem to be directed at).

    ::
    :: 2) The fat loss on very low carb was about the same as the
    :: weight loss on very low fat when given the exact same total
    :: calories. Not encouraging to folks who want LC to work faster
    :: then LF, but the question becomes how low in fat did they have
    :: to go?
    ::
    :: 3) No mention whatsoever of relative hunger reported by the
    :: subjects. Sometimes what's left out is interesting.
    ::
    :: 4) They discuss differing water loss levels. Ah, so that's how
    :: LC beats LF. Better early water loss on low carb, no surprise
    :: there.
    ::
    :: 5) They discuss methods for estimating lost lean using chemistry.
    :: So at least they are noticing that water loss differences occur,
    :: that fat loss happens on either low fat or low carb, and that
    :: both make it harder to measure lean loss.
    ::
    :: So it looks to me like their initial goal was to prove that LC
    :: causes more lean loss than LF, but the hard data failed to
    :: justify their iniial goal. As a result they used strange wording
    :: to hedge their bets.
    ::
    :: When studies fail to give the desired outcome that's what they
    :: read like. "Weasel words"
     
  8. Roger Zoul

    Roger Zoul Guest

    Susan wrote:
    :: x-no-archive: yes
    ::
    :: Roger Zoul wrote:
    ::: [email protected] wrote:
    ::::: so what does this mean in english??
    :::
    ::: From the paper:
    :::
    ::: "Conclusion
    ::: Although more long-term studies are needed before a firm conclusion
    ::: can be drawn, it
    ::: appears, from most literature studied, that a VLCARB is, if
    ::: anything, protective against
    ::: muscle protein catabolism during energy restriction, provided that
    ::: it contains adequate
    ::: amounts of protein."
    :::
    ::: Hence, if you get sufficient protein, you won't lose lots of muscle
    ::: while losing weight on LC. Weight lifting will tend to help
    ::: minimize muscle loss, too.
    :::
    :::
    :::
    ::
    :: 8 weeks is too short to really point out the differences in LBM,
    :: because the water whoosh of the LC dieters is counted as LBM loss,
    :: if I'm not mistaken.
    ::

    I agree. However, the author of the reply was basically doing a lit review
    and just providing info that weighs against a statement made by authors of
    another paper who seemed to think that LC is not protein sparing (hydration
    seemed to be an issue with a test they did). So I'm not really sure if the
    8 weeks is relevant.
     
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