Reply To This Post         Return to Posts Index           VegSource Home

From:	Jeff Novick, MS, RD, LD, LN (novick.vegsource.com)
Subject:	Seperating The Wheat From The Chaf: High Carb Diets, Nutritional Adequacy & Lipid Levels
Date:	August 22, 2007 at 4:51 am PST

An article I wrote a few months back..

There is often discussion about the "ideal" ratios of protein/carbohydrate/fat,
and the influence of different recommended diets containing differing
macronutrient ratios, on weight and lipid levels. And that the high carb (low
fat) diets are bad, as they increase cholesterol, and atherosclerosis.

In addition, because of lots of bad press over the last decade, many of us are
afraid of higher carb (low fat) diets, due to confusing and misleading press
reports indicting the high carbohydrate diet Americans have consumed over
the last 30 years.

As I have often pointed out, that while this typical American diet is high carb,
it is mostly refined white flour, white sugar, low in fiber, low in omega 3's,
lacking in most nutrients, and high in saturated fat, cholesterol and sodium.
This typical "high carb, low fat" diet that is consumed in American is not
really high carb, nor is it really low fat, nor is it a healthy diet in anyway.

More importantly, this typical American diet is not the high carbohydrate diet
that many of its true advocates (like me) would recommend nor do they
produce the same results in humans as the ones I recommend. High
carbohydrate diets that are based on unrefined, unprocessed plants foods
that are high in fiber, nutrient dense and adequate in protein and fat, are very
healthy. While these two differing diets may be somewhat similar in
macronutrient composition, they differ completely in food and nutrient
composition, and their effect on humans. Sadly, though, they are often
lumped together and judged as equally bad. The only real thing they have in
common is "bad press".

The following 5 studies focus on two examples of populations living on a very
high carbohydrate diet: one the Tarahumara Indians of Mexico, the second,
the native traditional Hawaiin diet.

Lets look at the Tarahumara Indians. Their diet is mostly corn, beans, and
peppers with very limited food from animal sources.

http://www.ajcn.org/cgi/reprint/32/4/905

The protein average 87 g, and meets the recommendations for all the
essential amino acids. Fat is only 12% of total calories, with 2% saturated and
5% polyunsaturated. The average dietary cholesterol intake is less than 100
mg/day.

Carbohydrate comprised 75 to 80% of total calories, however, unlike the
typical American high carb diet, only 6% of total calories were derived from
simple sugars. In America, it is ~20%. Their nutrient intake met or exceeded
national recommendations

In regard to its effects on lipid levels...

http://www.ajcn.org/cgi/reprint/31/7/1131

All lipid values were low (total cholesterol LDL, VLDL, etc), including HDL,
which was in the 20s.

Their life expectancy is low due to very high infant mortality but, as the
authors stated...

"Particularly notable was the virtual absence of the hypertension, obesity, and
the usual age rise of the serum cholesterol in adults. Thus, the
customary diet of the Tarahumaras is adequate in all nutrients, is
hypolipidemic, and is presumably antiatherogenic"

Now, some may say they are genetically predisposed to low cholesterol levels
and metabolize cholesterol differently. Maybe, but either way, their high
carb, low fat diet is nutrient rich and is not hurting them.

But the real test would be, what happens when you put them on the typical
American high carb diet, for 5 weeks. Do they still maintain their low
cholesterol levels, or do their numbers change like typical Americans.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?
db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=1944471&query_h
l=4&itool=pubmed_docsum

As you can see, they reacted just as most Americans do... Their cholesterol
went up 31%, LDL, rose 39%, HDL rose 31%, TGs, rose 18%, and their weight
increased 7%.

These same results that we see amongst the Tarahumara Indians has also
been seen and replicated/documented in Hawaii.

Twenty native Hawaiians, who were consuming the more traditional
American high carb diet, were placed on what as called the "pre-Western-
contact" Hawaiian diet for 21 d. So, they switched from the high carb
American diet, to the higher carb Hawaiian diet.

The "Hawaiian" diet was low in fat (7%), high in complex carbohydrates (78%),
and moderate in protein (15%). While eating "ad libitum" (no portion or calorie
restriction) the average calorie intake decreased from 2594 to 1569 per day
(around a 40% restriction, while eating to full). That's quite an impressive
decrease. The average weight loss was 22 lbs. The average cholesterol
decreased around 15% and BP decreased an average of 11.5 systolic and 8.9
diastolic

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?
db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=2031501&query_h
l=10&itool=pubmed_DocSum

In a second study, this same Hawaiian Diet was fed ad libitum (without calorie
or portion size restriction) to adults for 21 days. The Hawaii Diet was high in
complex carbohydrate (77% of calories), low in fat (12% of calories), and
moderate in protein (11% of calories).

Weight loss averaged 11 lbs, BP decreased an average of 136.0/82.7 to
125.5/78.9, cholesterol levels fell from 205.3 to 156.9, LDL from 125.9 to
94.9, and HDL from 38.3 to 31.3, Triglycerides from 238.7 to 152.2 and
blood sugar from blood glucose levels from 112.2 to 91.5

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?
itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids
=11320614

I believe that these diets, like the traditional native Hawaiian diet and the
Tarahumara diet, give us insight on how to effectively apply a reduced calorie
diet, while still acheiving optimal nutrition. These diets are nutrient dense,
highly therapeutic and, when the subjects are encouraged to eat until
satisfied without calorie or portion control, they achieved a 40% restriction.

So, don't be misled or confused by simple comparisons, criticisms (or praise)
done on macro nutrient ratios, without understanding the food that is
contributing to those macro-nutrient ratios and its effects on health. There
are many types of high fat diets, and high protein diets and there are many
types of high carb diets. And there are many types of food that can make up
either of them.

Some are very toxic.

So, yes, there are some really bad high carb, low fat diets out there. But
some, are not only extremely nutrient dense, but may be an extremely
healthy, (if not the healthiest) option.

In Health
Jeff

Reply To This Post         Return to Posts Index           VegSource Home