On Thu, 1 Jun 2000, Ken Stuart wrote:

> Fat does not convert to glucose, and therefore does not end up as body fat.

It's true that fat is not converted to glucose but fat does not
have to be converted to glucose to be stored as body fat.

> Eating fat CAN keep you from burning your own body fat, by being used instead of
> body fat.

Yes.

> However, if your diet contained zero carbs and zero protein, you would not GAIN
> weight, no matter how much fat you ate.

Not so. The body can and does store excess dietary fat in fat
cells.  It is true that fat gain is slower on an all-fat diet.
This is because insulin levels remain low when fat is eaten.  But
a low level of insulin is not zero insulin (in a non-diabetic),
and a person on an all-fat diet will soon be in ketosis, and the
more fat consumed, the more ketones will be produced.  Increasing
concentrations of ketones trigger the release of insulin, which
triggers the transfer of fatty acids in the blood to fat cells.

A person who eats large amounts of fat and nothing else will
first see a rise in free fatty acids in the blood.  As glucose is
depleted, the concentration of ketones will rise.  Eventually the
pancreas will start putting out insulin and the liver will start
binding the FFAs into triglycerides, so serum triglycerides will
rise as well, and the insulin will push the triglycerides into
fat cells.  Since the insulin response to ketones is less than
the response to carbs, this process is slower, so it takes longer
to gain fat this way.

Todd Moody
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