Hi Jim, 
When I was in touch with Dr. Cordain a year or two ago he said that he
advocated up to 30% fat content in the diet. I don't remember what he said
in his books. However, I advocate 60% to 70% of calories in fats for a
ketogenic diet and about 40% fats for a healthy maintenance diet. Before the
rise of the low fat nonsense, fats were considered necessary to nutritious,
tasty meals. I remember my grandmother cooking roasts with a fatty shell set
atop the roast. I don't know where the fat came from but my grandma lived to
99. That is a pretty good age for a person who traveled by covered wagon to
visit Yellowstone National Park as a child. Her aunt was hiding with her
parents under a bridge when natives crossed it on their way to Custer's last
stand. That aunt, who lived to 104 or 105, cooked roasts the same way.  

Trappers working in the Canadian north knew they had to eat beaver and other
fatty animals to stay warm and function in the extreme cold. Reliance on
glucose for energy does not allow for much endurance in that climate. One
must eat every couple of hours eating a glucose dominated diet. Even then,
you just can't stay as warm as when you eat fats. 

With all the peer reviewed publications showing benefits for people with
epilepsy, Alzheimer's, Parkinson's, cancer, etc. from a ketogenic diet, I
can't see how any honest person can seriously push a low fat regimen. The
ketogenic diet has also been shown to be neuroprotective. This is partly, I
suspect, due to the antioxidant properties of some ketone bodies. Unlike
vitamin C, which requires insulin to enter the cells and must therefore
compete with glucose to gain entry, the ketone bodies act as nutrients for
the brain (along with other cells) and they simultaneously scavenge free
radicals. That is a much more efficient system for protecting brain cells
from oxidative stress. 

The ketogenic diet also excludes grains so the blood brain barrier is not
compromised by dietary increases in zonulin production, thus providing
another layer of protection by preserving the BBB. 

I don't know Dr. Cordain's current position on fats or whether Gary Taubes
has had an impact on his thinking. I would certainly be interested in
hearing. 

Also, in keeping with Wally's post, I don't recommend a ketogenic diet to
everyone. There are more than a dozen genetic conditions in which people do
not metabolize fats very well. Equally, there are some conditions, including
celiac disease and non-celiac gluten sensitivity, where people do not
metabolize glucose as well as others. There are some people whose common
bile duct splits so the bile enters the small intestine at two separate
locations. I'll spare you the details, but I imagine that this would improve
their absorption of fats. 

Wally's comment on this thread captures the central thesis of the book I'm
working on. The whole one-size-fits-all dietary paradigm is silly. With 11%
of the US population showing gluten sensitivity and the data showing that we
don't metabolize glucose as well as others do, that alone should have us
seeing that our nutritional needs are not the same. There are variations in
base metabolic rates, vitamin and mineral needs, etc. For instance, black
people need more vitamin D in temperate zones than white people. Then there
are variations in just how pale or dark a person's skin is, and how tall we
are, which is a factor in how much energy it takes us to stay warm.     

Thus, for ketosis, I am willing to suggest certain parameters, but I know
that each of us will have to adjust to meet our individual needs, and that
is after ensuring that we do not have one of the many conditions in which
our fat metabolism is compromised. 
   
Best Wishes, 
Ron


> 
> Just the other day, I was wondering if we'd yet seen a reversal by
> Cordain on this issue.  What has he said about Taubes, if anything?
> 
> Jim
> 
> Quoting Ray Audette <[log in to unmask]>:
> 
> > Cordain's assertions are based on modern game species, not
> > Pleistocene Mega-fauna.