In a message dated 11/20/1999 8:37:21 AM Pacific Standard Time, [log in to unmask]
writes:

>
>  One last theory of mine.  Carbohydrates are used for fuel in the
>  body.  58% of protein and 10% of fat can be used for fuel in the
>  body.  But protein and fat have other uses, mainly building and
>  repairing the body.  So my theory (because it is true in my body)
>  is that is one reason I can eat more calories when my calories
>  come primarily from protein and fat and not carbohydrates.
>
>  Kara
>

another reason you can eat more calories of fat and protein, is that
they dont burn clean,,they are low octane, where as carbs are high
octane,,they burn clean and completely,,the rest have a lot of left
over calories that get *wasted* during the process...ie thrown away,
like unburned ketones. (this is mostly true of fat, protein can be
converted into glucose as you mentioned, but because so much
of it is used to repair tissue etc, its not the preferred source for
glucose, and even when it does get turned into glucose, this
process burns extra calories too.).