Jim Swayze wrote:
> I don't like the "selling out" language a couple of people have used, but I
> share in the disappointment. Not to say that there's no room for disagreement
> with the ideas presented in Neanderthin, but Dr. Cordain appears not to have
> read Ray's book at all.
If you read Ray's acknowledgements, he states that he "benefited greatly"
from conversations with Cordain. In other words, Ray, a layperson,
consulted with Cordain, because Cordain is a leading expert. Ray's book is
his interpretation of research done by Cordain and others, garnished by
various speculations. Every fact in Ray's book is from sources other than
Ray, sources readily available to a professor at Colorado State University,
more available to Cordain than to Ray, and Cordain has access to many more
minds involved in paleo research than Ray, so Cordain did not have to read
Ray's book to learn anything about paleo diet.
> For Cordain to, in
> effect, RECOMMEND periodic cheating and downplay the consequences is wrong.
Right and wrong are relative. It may be wrong for you, but not for others.
Since Ray is your guide, you might note that Ray mentioned liking Haagen
Daaz now and then. Further, some of the foods that Ray may eat daily or
often (like bacon or fatty ribs) are considered "cheat foods" by Cordain.
>
> It should be obvious that if we could live healthily on pemmican, nothing
more than dried meat mixed with a
> generous portion of fat, that there's something wrong with our overemphasis on
> keeping dietary fat low. Fat is a good thing.
Who can live healthily only on pemmican, and for how long? And what
pemmican--made with supermarket meat and fat, or with pasture-raised meat
and fat? The nutritional difference is vast and could make the difference
between health and illness. Not everyone can eat pemmican regularly or
daily without ill effects.
Which fat is a good thing? Omega 6 fat? Omega 3? Saturated?
Monounsaturated? Trans? Corn oil? Lard? Margarine? Crisco? Butter?
For whom is fat a good thing? Some people can eat high fat diets and fare
well, some can not.
How much fat is a good thing? A little may be good but is more better? How
much is enough?
Everything is relative.
> it has had enough. And It's important to remember that obesity is not a
> function of fat or calorie intake. It is nothing more than the body's defense
> to the alien proteins found in non paleo foods.
Nice piece of speculation from Ray but not a fact.
The alien protein theory is clearly contradicted by the millions of Asians
who consume various "alien" proteins in quantity as a part of their diet
composed of an average of one pound (dry weight) of grains per day, and yet
remain lean throughout life. I'm not saying that the Asian diet is ideal
but merely showing that evidence contradicts the idea that consumption of
alien proteins from neolithic foods is the 'true' cause of obesity.
Most of us will find that Ray's speculation has not released us from the
laws of thermodynamics. Thus, for most--if we eat more energy than we
release in activity or body heat, we store the excess as fat. And with fat,
for many people, perhaps not all, it is much easier to eat excess energy as
fat than as lean protein or produce.
As far as the science goes, there is a relatively large amount of converging
evolutionary, clinical and lab evidence supporting the view that for most
people excess dietary fat is harder to burn and more easily converted to
body fat than any other nutrient, and low to moderate (20-30%) fat, high
protein diets result in faster fat loss than high fat diets (provided that
the carbs in the diet are unrefined whole foods). Fat supplies twice as
much energy per gram than protein or carbs, and it does not stimulate
thermogenesis (unlike protein or carbs). And, this makes evolutionary
sense, as fat is across the plant and animal kingdoms the best method for
long term storage of lots of energy in small packages. In animals, carbs
and protein are just too bulky to be useful for storage of energy. In all
species, fat stores are protection against death from starvation. Hence,
there is a biological preference to burn protein and carbs and store fat.
Of course some will jump on this and say that all "excess" carbs are turned
to fat but research just does not support this belief. Most excess carbs
are stored first as glycogen. Further, if you are eating only paleo
carbs--vegetables and fruits--it is almost impossible to eat too much, the
food is just too bulky. The problem is, people are eating lots of high
density carbs AND lots of fat, seasoned with salt--bread and butter--so the
carbs are burned while fat is stored.
Low carb advocates then say, cut the carbs, lower your insulin, deplete your
glycogen, go into ketosis, to "force" your body to burn fat. But in fact
you don't have to "force" your body to burn fat, as some fat is continuously
used as a part of the cellular fuel mix. In fact, regardless of diet, about
60% of ongoing energy needs in a human body are provided by fat.
There are plenty of people who can lose body fat on diets that are neither
low carb nor ketogenic. Anyone can do so by eating less fat than the body
burns. To illustrate, if a man burns 2000 calories per day, and 60% of
this is from fat, then he burns 1200 calories of fat daily--i.e. about 120
grams. So long as he eats less than 120 grams of fat and no more than 2000
total calories daily, he will gradually lose body fat--and the less fat he
eats, the faster he burns body fat. For example, if this person eats 2000
calories including 110 grams of fat, he will burn only 10 grams of body fat
daily; but if he eats 2000 calories including only 60 grams of fat, he will
burn 60 grams of body fat daily. This is not speculation as controlled
studies have shown that people can gradually lose body fat on "maintenance"
calories so long as fat balance is negative (less fat is ingested than is
burned).
Conversely, if this person chose to eat 2000 calories, with 75% of calories
as fat, he would (if typical) gradually gain body fat, because he will be
burning only 120 grams of fat daily, but will be eating 150--the extra 30
grams of fat will just be stored because the body in most activities just is
incapable of burning a fuel mix much richer than 60% fat (it has to have
glucose, either from carbs or from conversion of protein). The limit is
imposed by the fact that burning fat requires a larger amount of oxygen than
carbs--and the lungs and blood etc can only deliver so much oxygen per unit
of time. (If you have ever noticed easily running short of breath when on
a ketogenic diet, this is the reason.)
Ketogenic diets increase acid load of the body, they impair the burning of
body fat (because fat can't be burned well without glucose), and in ketosis
the body MUST destroy muscles and liver to gain glucose to fuel the brain.
Yes the brain can adapt to burning ketones, but only to an extent--at most,
it can run on a mix of 2/3 ketones and 1/3 glucose.
If man is designed for a low carb diet, it sure is hard to explain why we
have amylase in our saliva and compartments for storing up to 400 grams of
glycogen.
If you have high calorie expenditure in a low carbohydrate environment
(Inuit), or are a tall lanky type I diabetic who can't store much fat
because you have extraordinarily low levels of insulin (Ray), a high fat
intake may be necessary and desireable. But is it so for everyone?
Not for many people, like me, who have also found that too much fat in food
readily results in too much fat on the body. My best fat loss results have
always come with diets providing less than 30% of calories as fat.
My wife Rachel has been able to gain fat on a high fat, low carb paleo diet.
At one time (many years ago) she lost fat on a low (>20%) fat, high complex
carb (grain and legume rich) diet. Her best results appear to come from a
moderate (25-35%) fat, high protein, produce rich paleo diet including
several servings of fruit daily.
Yet some have an opposite experience. Everything is relative.
We need to stop the ingrained
> habit of looking at fat and calories, listen to our bodies, and simply ask if
> the food we're about to eat would have been eaten by our paleolithic forbears.
Go ahead and ask the question. The problem is, none of the foods in front
of us today would have been eaten by our paleo ancestors. Everything has
changed including wild foods! And by the way, perhaps you missed it, but
Cordain's book is an attempt to answer the question, and show you that foods
like fatty meat would not have been regularly eaten by our ancestors.
Don
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