On Fri, 26 Nov 2004 18:44, Ken Stuart wrote:

>
>The point is that it is not that simple.
>
>The human metabolism does not look for "energy" and "calories".
>Instead, it runs a variety of chemical reactions.  Some of these
>reactions require amino acids, some require lipids, some require
>glucose.   They are not interchangeable.
>
>In the 1950's, a researcher (Peatwick, I believe?) put three groups of
>people on three different diets, each of which contained 1000
>calories.   One was 1000 calories of protein, one was 1000 calories of
>carbohydrates, and one was 1000 calories of fat.
>
>The three groups lost differing amounts of weight on these diets -
>something which thousands of "experts" have ignored *after* the
>research was done, and continue to prescribe certain numbers of
>"calories".

As a practical application of Ken's point, consider the calories of
protein.   Most popular books on diet assume that protein and
carbohydrates have the same caloric content: round about 4.2 calories per
gram.  Barry Groves has pointed out that some protein is used for body
maintenance and this reduces the effective calories significantly
(depending on the body's need for protein).  Barry wrote a useful post
covering this and much more on the Paleodiet list last year.  With Barry's
permission I have copied his post to my site:

http://www.evfit.com

Follow the link to <calories> under the subheading <Food>

Keith