Cory wrote:

>Just read a book today that strongly supports the Paleo diet.  The theory
>here claims that "pyruvic acid in the blood is responsible for obesity,
>because it prevents the utilization of fatty acids and blood sugar, and
>causes them to be stored as excess tissue.  The solution is infallible IF
>PROPERLY ADHERED TO.  Limiting vegetarian foods lessens the amount of
>pyruvic acid in the blood;


This theory overlaps considerably with Dr. George Watson's research on
metabolic differences.  Some of his subjects were "fast oxidizers" for whom
glycolysis (oxidation of sugar) occurred unusually fast.  The end product of
glycolysis is pyruvate, which feeds into the Krebs cycle, where most (~80%)
of our energy is produced.  Pyruvate is further oxidized, yielding both
o-acetate and acetate.  However, pyruvate yields far more o-acetate than
acetate, which can result in inefficient energy production, since the Krebs
cycle runs well only if the amounts of o-acetate and acetate are balanced.
Protein and (especially) fat are much better sources of acetate.  A
high-carb diet will cause a fast oxidizer to rely primarily on glycolysis
for energy, and prevents fat from being utilized properly (Watson's fast
oxidizer subjects often had low blood sugar and high lipid levels).

Other subjects, however, were classified as "slow oxidizers," because they
oxidized sugar at an unusually slow rate, forcing them to depend on fat for
energy; this imbalance tended to result in high blood sugar and low lipid
levels.  Pyruvate supplements are popular, so it would seem that some people
benefit from additional pyruvic acid.

Some of Dr. Anchell's advice confuses me.  He seems to base his
recommendations primarily on the pyruvic acid content of a food.  As I've
discussed above, our body is constantly manufacturing pyruvate from
carbohydrates, so the emphasis seems misguided.  Caffeine stimulates insulin
production, which in turn facilitates carbohydrate metabolism, which could
increase the rate of production of pyruvate.  I had never thought before
about the pyruvic acid content of foods, so Dr. Anchell's perspective is
intriguing.

Cheers,
-- Aaron Wieland