On Tue, 5 Feb 2002 10:34:55 EST, S C <[log in to unmask]> wrote:


>I think that root vegetables and rhizomes differ from starchy tubers in the
>amount and type of  carbohydrate the contain.  I can't be sure about every
>vegetable out there, but I know that beets for one contain sucrose--a
>disaccharide.  That's easier to digest than starch (amylose or
amylopectin).
>Also, roots tend to be much lower in carbohydrates than starchy tubers.

We have a very good description of Australian Aboriginal Plant foods from
Brand-Miller/Holt, Nutrition research reviews 1998.
It contains a lot of data on the roots, tubers, bulbs (alongside with
fruits seeds legumes vegetables flowers) these people eat.
And comparisons with today's cultivated items.

As a rule of thumb the nature have more fiber,less carb,more protein,
like:
                 fiber         carb          protein
cultivated r.    2+-1         21+-27       1+-1
nat.roots        8+-7         17+-13       2+-3
nat.tubers       6+-4         22+-12       2+-2
nat.bulbs        8+-6         38+-23       2+-1
cultiv.grain    10+-4         72+-2        11+-2
nat.seeds       18+-16        45+-22       12+-8

A cooked ordinary potatoe has about 17% carb, a sweetpotatoe 22%.
Seeds/Grains have very much more carb, both natural and cultivated.

That's a slight increase in carb in cultivated items, but not very much.
Very much higher is the fiber part in natural items.
A similar tendency is also found in Nuts, Seeds, pith,stalk,buds and
legumes if you compare the natural items with their cultivated counterparts.

regards,
Amadeus S.








>
>> It's true that [Cordain says in his paleo diet book to avoid starchy
tubers
>and eat only honey as a sweetener], but unfortunately he offers no
plausible
>paleo-based justification for the restriction.
>
>It's true that Cordain offers no paleo-based justification for this, or for
>many of his other pronouncements.  This is what bothered me most about his
>book.  But I think there is some evidence that our ancestors didn't eat a
lot
>of starch.
>
>Our bodies don't well tolerate a very high carbohydrate diet. All kinds of
>problems follow from this--rampant bowel disease (this is a very widespread
>problem), insulin resistance, etc., etc.  This tends to suggest that we
>evolved on a diet that was moderate in carbohydrates (that is to say, much
>lower than the standard American diet), and this is the opinion of most
paleo
>nutritionists.
>
>Starchy tubers and grains are the main source of polysaccharides in the
>modern diet, and they are also almost pure carbohydrate.  If these foods
were
>as widely available in paleo times as they are today, then the paleo diet
>would have been much higher in carbohydrates than it apparently was.  There
>is fairly broad agreement that paleo people didn't eat grain.  Just the
fact
>that we are not designed to eat a very high carb diet tends to suggest that
>starchy tubers also played a small role.  Many starchy tubers also need
>cooking to be edible, which is another point against them.