On Thu, 25 May 2000, Eric Armstrong wrote:

> One possiblity I hate is that of a genetic metabolic shift that
> occurs with age. I don't even like to *think* about such a thing,
> but I suppose it must be considered.

Well, there are fairly documented hormonal changes that occur as
one ages, so this is a possibility.  But then again, I'm only
46, which isn't *that* old.  And anyway, I've had a weight
problem most of my adult life.

But my current theory is that the culprit is LPL.  If you look at
Chuck Forsberg's "Adiposity 101" (which is a must-read for anyone
with a weight problem, in any case), at
http://www.rdrop.com/users/caf/adipos.html, you'll find some
discussion of the enzyme lipoprotein lipase (LPL), which does a
number of things, such as storing fat and causing production of
LDL cholesterol.  As we lose weight, LPL levels tend to rise, and
the more weight we lose, the more they rise.  The more LPL we
have in circulation, the harder the body is trying to store fat,
which makes it harder to keep weight off.

> Another possiblity is what we might want to call "quality" of
> LBM. DeVany really focuses on fast twitch fiber. He points out
> that the phosphates that fire the fast twitch fiber are replenished
> on a pathway that burns fat preferentially. Are you involved in
> fast twitch exercises?

Yes.  This is probably why I haven't lost LBM.

> A third possibility is that the fat burning pathways are blocked
> somehow, even though they would ordinarily be preferred. Insulin
> does that, I understand. Anything that might tend to keep insulin
> levels high?

The only things I can think of are too many calories and/or
saturated fats.

> A fourth possiblity comes under the EFA heading. If cell-wall
> function is impaired by trans fats, then a "normal" amount of
> insulin will be only partially utilized. The excess will keep
> circulating in the blood stream. The problem is, you've been on
> a pretty healthy diet for quite a while, it seems. So it's hard
> to see how that could explain things (unless you have some ideas
> on the subject).

It's well documented that saturated fats contribute to insulin
resistance -- at least, some of them do.  Myristic and palmitic
acid are the main suspects.  They, like trans fats, appear to
impair cell-wall function.  I really don't know if this is the
problem, but it could be a contributing factor.

Todd Moody
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