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Old February 13th, 2004, 05:41 PM
kvs
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Default Uncovering the Atkins diet secret

"Moosh" wrote in message . ..
On 12 Feb 2004 19:16:05 -0800, (kvs) posted:

"J Stutzmann" wrote in message ink.net...
Thermodynamics --- a law we can't live without! [grin]


It's not a law but a collection of laws. Thermodynamics is about the
aggregate statistical behaviour of systems, assuming a Boltzman
distribution for the energy in the states of the system. You cannot
reconstruct the microphysics of a system starting with thermodynamics.



wrote in message
news:slbWb.19977$032.64937@attbi_s53...
In sci.med.nutrition tcomeau wrote:
: Maybe the lesson to be learned is that calories really have little
: bearing when it comes to weight gain or loss in humans.

1) Please learn to trim quotes
2) Have you somehow forgotten the laws of thermodynamics? It is quite
simple: if energy in energy out, the body will gain mass.


Wow. The reverse of a nuclear explosion! There are no mass-energy
conversions in chemical reactions.


Who said there were?


Ever hear of sarcasm?


You gain mass because the various
chemical reactions in your body that keep you alive start storing some
of the mass that you consume instead of extracting chemical energy
from it and excreting the mass.


Or you store excess chemical energy in your food intake as chemical
energy in the body. A gram of fat stores 9 calories, and a gram of
carb and protein stores 4 calories of energy.

Now what triggers this mass storage?


Excess energy in the system.


Fat storage is triggered by specific chemical messangers. When you
eat a low fat, high carb diet malonyl CoA levels are high and inhibit
fatty acid oxidation by inhibiting carnitine-palmitoyl transferase I,
found in the outer mitochondrial membrane. As a result most fatty
acids end up as triglycerol for export in VLDL lipoprotein by the
liver. Fatty acid synthesis occurs in response to a high carb, low
fat diet. Glucose is converted into pyruvate in the cytoplasm, which
is then transported into the mitochondria and converted into
acetyl-CoA and carbon dioxide. Acetyl-CoA is converted into
Malonyl-CoA by acetyl-CoA carboxylase (ACC). Acetyl-CoA and
Malonyl-CoA are are two key stages of fatty acid synthesis. ACC is
inhibited by glucagon and epinephrine (i.e. a high protein diet and
exercise) but ACC is activated by insulin and citrate.

Receptors on adipose cell surfaces respond to the glucagon/insulin
ratio. If the ratio increases (fall in insulin or increase in
glucagon or both) then lypolisis is triggered. Glucagon increases the
phosphorylation of hormone sensitive lipase (HSL) by increasing cAMP
and the cAMP-dependent protein kinases. Insulin decreases HSL
phosphorylation through processes that decrease cAMP and activating
phosphatases that inactivate HSL by removing phosphates from it.


It isn't thermodynamics,


Thermodynamics is just a succinct statement that energy can neither be
created nor destroyed, something that some here seem to overlook, at
times.


it is the design of the the cellular
chemistry and cell microphysics.


No, excess energy in the system is just stored as chemical energy in
the body tissues. No excess, no storage.


I just described for you the physical difference between individuals
with different numbers of insulin receptors in their cell membranes.
Putting it in your terms, the insulin resistant individual will have a
much lower threshold for "excess" than the "normal" individual when it
comes to a high carb diet. So the advice for them is to avoid high
carb diets at all costs if they don't want to become obese. The same
number of calories for the same ideal body weight will make then gain
fat while the "normal" individual will gain nothing.


Different people have sufficiently
different microphysics (e.g. number of insulin receptors in their cell
membranes) that assuming that one energy balance model works for
everyone is absurd.


Less receptors just means the reaction is slower. The end point is
the same however.


For the appropriate level of caloric intake one individual will have
no weight gain while the other will have adipose fat storage working
for a longer period of time. The chemical energy that would have been
converted to heat through cellular respiration in the "normal"
individual will have to be stored as fat in the insulin resistant
individual. It would be nice if insulin resistant people could just
dump the fraction of glucose that they cannot burn compared to the
"normal" people but it doesn't work that way.



One person who consumes several slices of bread
or any other starchy food will respond to the induced insulin spike by
producing more heat while another will respond by storing fat created
from the starch (which is a collection of glucose molecules). The
system of each of these individuals will obey the laws of
thermodynamics but clearly the result is different.


But of course this different heat output is insignificant. Otherwise
folks would overheat. How is extra heat generated when muscular
activity is not increased? The BM generally produces enough metabolic
heat to keep folks comfortable. (In reasonable climates, that is


I percieve a noticeable increase in my heat output after a meal. Fat
accumulation is really slow. Of course by stuffing oneself fat
accumulation can be made quite rapid. My point is that a high carb
meal with the appropriate amount of calories will do different things
to different people. So insulin resistant people have to literally
starve themselves in order to eat high carb meals and not gain weight.
This is a recipe for morbid obesity and not health.
By shifting the protein and carb ratio of the meal, while keeping the
number of calories fixed, insulin resistant people can avoid the
nightmare.


If
energy out energy in, the body will lose mass.


Yes, just like in the fission of Unranium nuclei....


WTF are you talking about? 1000 calories of food in, and 500 calories
of energy out, and you will have 500 calories of excess energy stored.

That will be a couple of ounces of fat, thankyou very much.


You are missing the point, comletely.