On Sat, 24 Jan 2004 12:58:02 GMT, posted:

"Moosh" writes:
On Sat, 24 Jan 2004 12:07:13 GMT, posted:
writes:
On 23 Jan 2004 12:07:49 -0800, (tcomeau) posted:

It has nothing to do with the Laws of Thermo. They apply to a
closed system. The human body is not a closed system.

Where does it state that the "conservation of energy principle"
applies only to a closed system?

In any text that covers thermodynamics. However, some conclusions
can be drawn anyway; the previous poster is incorrect.

Energy is conserved whatever. Over what arbitrary boundaries energy
transfers are measured, determines what a "closed system" is.

Never said otherwise.

OK, I thought you said conservation of energy only occurred in a
"closed system" (whatever that arbitrary system means exactly).

However, a locked room containing food for a month and a chemical
toilet IS a closed system.

Exactly! Draw the boundaries and measure the energy transfers.

Yup.

The human body can be studied as a closed system. It depends what you
measure and how rigorously.

Right.

I've been waiting many months for TC to point out ANY metabolic lab
study to show that a hypercaloric diet can result in fat storage
loss. No show, but he still persists.

I'm not sure what you mean by "hypercaloric". Nobody has ever disputed
that a normal person eating 5000 cal/day will not lose weight. What is
claimed, and some of us have measured in practice, is that changing
the source of calories WITHOUT changing the number of calories has
changed us from gaining or maintaining to losing.

So show us the metabolic lab studies to back this assetion up.
"Hypercaloric" means taking more calories into the body than are
expended by that same body. There are two other self-explanatory terms
that go with this; "Eucaloric", and "hypocaloric".

Here the SECOND law of thermodynamics is relevant: no conversion is
100% efficient. Therefore, an easy corollary states that two different
conversion methods are a priori unlikely to exhibit the same efficiency.

The general principle of conservation of energy means that a calorie
can neither be created nor destroyed. All must be accounted for.
Efficiency is irrelevant. All calories into this system (the human
body) must exactly equal all calories out of this system. If they
don't, then the measurements are wrong, until you can get the Nobel
Prize for changing Faraday's Laws

I am unaware of any study measuring the exact conversion efficiency of
the conversion process for various fats and simple or complex carbs.

Conversion to what? All chemical reaction pathways have been studied
rigorously. There are reference books that can tell you the exact
thermal equations for every known chemical reaction.

Moosh