On Sun, 11 Oct 1998, Ilya wrote:

> Please notice that James was writing about specific people whom he actually
> saw eating this stuff. Also, his 'bottom line' statement, while probably
> intended to state that these people overeat didn't actually say that.
> It said:
> > Bottom line, if a person is heavier
> > than they want to be they eat more calories than they burn.
> technically this is true, even if you are eating very little (because you
> may have lowered your metabolism by dieting so much that you are burning
> even less).

This is correct.  It's one thing to state that overweight people
eat (or have eaten) more calories than they use; it's another to
state that they eat more calories than lean people.  The latter
may sometimes be true, and sometimes false, but it doesn't follow
from the former.

There are many theories about obesity, including the "foreign
proteins" theory.  We still don't really know which theories are
likely to be valid for a given individual.  I think we *can* say
that the body only knows how to do one thing with stored
(adipose) fat: It knows how to use it as fuel.  If this is
correct, as I think it is, then the only way to get rid of this
fat is to burn it faster than it is replaced.  The rate at which
fat is stored depends on a number of things.  One is certainly
insulin.  This is why low-carb diets work; they help to slow this
rate a bit by lowering insulin levels.  And glucagon is the
hormone that controls the conversion of fat to energy, which is
why it is important to have enough protein, since only protein is
a significant stimulator of glucagon.  But even on a lowcarb diet
there is enough insulin to replace fat as fast as it is burned,
if there are sufficient calories for the purpose, so the
insulin/glucagon balance alone is not sufficient to cause weight
loss.  But if the caloric supply drops a bit, then having low
insulin levels and a strong glucagon response will help to
facilitate the efficient use of body fat as fuel.

Another factor, unfortunately, is the activity of the enzyme
lipoprotein lipase (LPL).  Along with insulin, this enzyme causes
fat storage.  The unfortunate part is that the more weight you
lose, the more active this enzyme becomes.  It is because of LPL
that "rebound" weight gain can be so astonishingly rapid.  This
is another illustration of the assertion that we are "programmed"
to conserve or replace our fat stores, if possible.  I don't have
any information about whether LPL activity subsides after a while
if the lower weight can be maintained.  Some say that the point
of lowest LPL activity determines the body's "setpoint," but I
don't know if that has been corroborated.

My *guess* is that most obesity is a consequence of being
subjected to unnatural feeding patterns and unnatural foods for
an extended period of time.  In the wild, we would have
opportunities for occasional moderate weight gain, followed by
conditions that would force fat reduction.  We would seldom be in
a position to become obese.  In civilization, we have many
opportunities for obesity.  For example, I was a bottle-fed baby,
and my mother thought it was charming that I would gladly accept
*double* the recommended amount of baby formula (perhaps because
it was nutritionally poor).  And then, of course, I grew up in a
world of refined carbs.  The fact that I only became moderately
obese is probably a genetic advantage: No one in the family from
my parents' generation had a weight problem.

But my main point is that once we become obese the difficulty of
losing fat is not unnatural.  I think it is quite natural for the
body to tend to conserve fat; it's just not natural for it to
have so much to conserve.

Todd Moody
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