Amadeus Schmidt wrote:
> Still it appears to me, that the purpose that kestone bodies are
> produced for, is *not* to discard some excess kalories.
I merely pointed out that your statement that calories can't be
'discarded' was wrong. Additionally, as far as I know, very little
has been done to see what/how much is being lost in stool. Ketones
in urine, breath, and sweat was simply a very well known (even to
you) example of this.

> (to the opposite, animals or humans eating animal bodies are in
> trouble to aquire enough calories and have to convert protein for).
No trouble. I also don't see any problems using protein for energy, if
it is plentiful in the diet and the bulk of calories comes from fat.

> Ketone bodies seem to be a by-product of energy acquisition
> from fatty acids, and therefore constitute a (small) energy loss
> in this pathway.
If I remember correctly, when fat is burned incompletely and ketone
bodies are left over, only 5 calories per gram are used up, 4 are
'left over' as ketone calories. Thus, about half of the energy
from fat is going unused FOR THAT PORTION OF IT WHERE KETONE BODIES
AREN'T USED UP AS WELL. So the question is - exactly how much is that?
I personally don't have an answer, somebody on the low carb exercise
list posted some calculations (me thinks it was Lyle), but then
changed them significantly. At this point I am unaware of any
studies that would quantify this.

> I've read at the site:
> http://medtstgo.ucdavis.edu/endo/lecture/metlipid.htm
> >... Ketone bodies...  A third ketone body, acetone, is
> >produced by non-enzymatic decarboxylation of acetoacetate.
> > Ketone body formation occurs exclusively in liver and,
> >although prominent in both starvation and diabetes,
> >it is not known to be under direct hormonal control.
> >It appears to occur
> >predominantly because of the high rate of delivery of fatty acids
> >couple with the removal of oxaloacetate for gluconeogenesis.
> >All three ketone bodies, acetoacetate, ß-hydroxybutyrate and
> >acetone, readily exit the liver into the systemic blood.
> >The body is unable to metabolize acetone,
> >and it is eliminated in the urine and exhaled by the lungs.
>
> I think ketone bodies are a small hope if someone is trying to
> loose excess kalories.
If that's the case, then how do you explain people who eat
FAR above their maintenance levels of calories and still loose
fat, or don't gain any? I am talking about 5000 calories per day
in fat and protein. I am also talking about people who used to
gain weight on 2500 calories per day when eating carbs as well.

> The focus on energy balance should be, IMHO in our
> intrinsic hunger/appetite regulation.
Sorry, don't understand what you are trying to say here

> My guess is, that this "set point" is most often determined by the
> availability of one or few essential micronutrients in food.
This is a pure speculation on your part. If not - could you reference
your sources please.

Thanks
Ilya