IS A CALORIE REALLY A CALORIE? METABOLIC ADVANTAGE OF LOW-CARBOHYDRATE DIETS

Thanks Roger. You're one of the best posters in here.

"Roger Zoul" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I think this paper has been discussed here already (most certainly the
topic has) but I thought some LC newbies might be interested.

ABSTRACT
The first law of thermodynamics dictates that body mass remains constant
when caloric intake equals caloric expenditure. It should be noted,
however, that different diets lead to different biochemical pathways that
are not equivalent when correctly compared through the laws of
thermodynamics. It is inappropriate to assume that the only thing that
counts in terms of food consumption and energy balance is the intake of
dietary calories and weight storage. Well-controlled studies suggest that
calorie content may not be as predictive of fat loss as is reduced
carbohydrate consumption. Biologically speaking, a calorie is certainly
not a calorie. The ideal weight loss diet, if it even exists, remains to
be determined, but a high-carbohydrate/low-protein diet may be
unsatisfactory for many obese individuals. Journal of the International
Society of Sports Nutrition. 1(2):21-26, 2004
Keywords: low-carbohydrate diets, ketogenic diets, high-protein diets,
obesity, energy balance, Atkins diet, body composition, thermodynamics

http://www.sportsnutritionsociety.org/site/pdf/Manninen-JISSN-1-2-21-26-05.pdf

There's a new study to chew on right now that pits
low carb against two other higher carb diets. Some
of the results are interesting--particularly the
fact that as much lean mass was lost on the low carb
diet as on the low fat diet.
http://www.nutritionandmetabolism.com/content/pdf/1743-7075-3-7.pdf
--

Roger Zoul said:

I think this paper has been discussed here already (most certainly the topic
has) but I thought some LC newbies might be interested.
http://www.sportsnutritionsociety.org/site/pdf/Manninen-JISSN-1-2-21-26-05.pdf

x-no-archive: yes

Bill Eitner said:

There's a new study to chew on right now that pits
low carb against two other higher carb diets. Some
of the results are interesting--particularly the
fact that as much lean mass was lost on the low carb
diet as on the low fat diet.

That's because the study was so short; the big water whoosh experienced
by the low carbers is counted as LBM loss.

Susan

I posted that link here the other day. I also posted another link where an
author claims that the DEXA data used by the authors in the paper you
reference below leads to an incorrect conclusion (by the authors). Here's
the link:

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

and the author of this commentary paper says:

"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. "

Bill Eitner wrote:
:: There's a new study to chew on right now that pits
:: low carb against two other higher carb diets. Some
:: of the results are interesting--particularly the
:: fact that as much lean mass was lost on the low carb
:: diet as on the low fat diet.
:: http://www.nutritionandmetabolism.com/content/pdf/1743-7075-3-7.pdf
:: --
:: Roger Zoul wrote:
::: I think this paper has been discussed here already (most certainly
::: the topic has) but I thought some LC newbies might be interested.
:::
http://www.sportsnutritionsociety.org/site/pdf/Manninen-JISSN-1-2-21-26-05.pdf

Susan said:

x-no-archive: yes

Bill Eitner said:

There's a new study to chew on right now that pits
low carb against two other higher carb diets. Some
of the results are interesting--particularly the
fact that as much lean mass was lost on the low carb
diet as on the low fat diet.

That's because the study was so short; the big water whoosh experienced
by the low carbers is counted as LBM loss.

That's what I thought too, at first.
But one of the comparison diets, the
very low fat diet, resulted in almost
the same LBM loss. Obviously a very
low fat diet won't produce a water
woosh. And while I want to believe
that the extra LBM loss on the low fat
diet was muscle and the extra LBM loss
on the low carb diet was water, there's
no hard data to support it.

After reading the study I decided to do
a little research on the body composition
protocol that was employed. While the
DEXA method provides a 3 compartment model
(lean mass, bone mass, fat mass), it still
can't tell the difference between protein
and water. Supposedly, a 4 compartment
model (bone/mineral, protein, water, and fat)
has been suggested. Until a 4 compartment
model is put into use, I guess the only way
to differentiate muscle and water loss during
a study would be to include some type of
strength and/or basal metabolic rate measurement.
Unfortunately, this particular study didn't
include anything like that.

Here's a link to a brief discussion of the
DEXA body composition measurement method:
http://www.regence.com/trgmedpol/radiology/rad41.html
--

The DEXA data is definitely in conflict among the
references cited in very-low-carbohydrate diets and
preservation of muscle mass article.
--

Roger Zoul said:

I posted that link here the other day. I also posted another link where an
author claims that the DEXA data used by the authors in the paper you
reference below leads to an incorrect conclusion (by the authors). Here's
the link:

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

and the author of this commentary paper says:

"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. "

Bill Eitner wrote:
:: There's a new study to chew on right now that pits
:: low carb against two other higher carb diets. Some
:: of the results are interesting--particularly the
:: fact that as much lean mass was lost on the low carb
:: diet as on the low fat diet.
:: http://www.nutritionandmetabolism.com/content/pdf/1743-7075-3-7.pdf
:: --
:: Roger Zoul wrote:
::: I think this paper has been discussed here already (most certainly
::: the topic has) but I thought some LC newbies might be interested.
:::
http://www.sportsnutritionsociety.org/site/pdf/Manninen-JISSN-1-2-21-26-05.pdf