>From:	"Roy P D'Souza" <[log in to unmask]>:

Doug previously wrote:
>>The body has a pool of about 2500 calories of glygogen which
> it uses for its energy needs.  Unless you've just fasted for a
> couple of days & drained this pool, you have room for only so much of
> extra sugars which are taken in & converted to glycogen.  The
> excess gluscose will spill over into the bloodstream, where it
> contributes greatly to aging/disease.  It doesn't matter whether this
> glucose originates from the finest organically-grown tropical
> fruits, it is still a nasty substance which does you no good.  Say you
> have room for 800 calories before you top off your glycogen stores.
> If you take in more than that at one meal you are asking for
> trouble.  The best course is to fast or diet so that your pool is never
> full & contains lots of room to handle what you take in at your
> meals.

>>Guess what, vegetables are a lot safer in this regard than
> fruits, as their calories are absorbed at a much slower rate.
>>...<sig deleted>

>I'm interested in finding out if there is a glycemic index
> for fruit that would help select those that would minimize overflow of
> this glycogen reserve pool.

We had a discussion about this on the CR list a while back, & it is
not as if there are definitive answers which can be given about the
whole subject of how to keep your blood glucose levels from spiking
up.  There are GI tables.  Try a WWW search, and you might want to
look at www.vrp.com where I know they have some stuff on GI.

>I suspect that fruit such as cucumbers, tomatoes and
> avocadoes would have lower indices than sweet fruit such as
>persimmons.

Yeah, I think you are essentially correct, but tomatoes I suspect
may have more sugars, hence a higher GI (the book I need to
reference to find the answer is hiding from me right now).  The
thing you need to understand is that the various sugars found in all
produce vary widely, in ways that our taste buds are not reliable
indicators of.  Fructose has a very low GI, sucrose very high.
Sucrose will split into glucose & fructose in the body, & I have
seen (but do not believe) speculation that fructose (& hence sucrose
too) can raise havoc in your body.  The whole thing is somewhat
unclear to me (& I expect to everybody else too).  One thing which
is clear is that caloricly restricted individuals will  handle this
a lot better than others, and that it is of course unwise to consume
a heavy sugar load all at once.  Here are some facts:

Expressed in gm/100gm of fresh produce [where F=fructose, G=glucose
& S=sucrose]:
carrot    F-.85 G-.85 S-4.24
cabbage    1.20  1.58   .15
asparagus  1.30   .92   .29
banana      3.5   4.5  11.9
apricot     1.3   1.7   5.8
grapefruit  1.2   2.0   2.9

You can see that carrots (& even more so with beets) & bananas are
loaded with sucrose, & for me at least I get a jolt from a large
glass or more of carrot juice because of this.  In other words,
watch the carrot juice as it can send you blood glucose
skyrocketing.  Don't get me wrong, I am not saying to avoid
high-sucrose foods, just do it in moderation.  The book I need is
devoted to fructose metabolism, & even after reading it I was
confused because the data is not at all clear.  One thing which is
clear is that after making a sudden change in the composition of
your diet it takes the body a little while (I think you are talking
a week or two) to catch up & begin producing the necessary
substances it needs to handle the sugars, etc. in the new food
supply.  I think that fructose may well be fine, & that foods with a
high proportion of the calories from fructose might be desireable as
this gives you such a low GI.  But I would not want to take a strong
stand on this at the present.  Again, vegetables are going to lead
to a lot less trouble in this regard (excepting ones such as carrots
or beets). Juiced vegetables (or fruit) will of course cause you to
take in probably more than you would if eaten whole, and cause the
more sudden assimilation of the sugars.

>What about tubers? would one classify carrots and sweet
> potatoes as more like veggies or fruit?

Carrots are more like orange-colored sugar cane, especially when
juiced so that you take in more at one meal than you would if eating
them whole.  When I do get ambitious enought to juice some, I try to
dilute it with celery or some other green juice.

Rene's notion of classifying certain vegetables as fruits does has
some validity I think, & the Pythagoreans (who were vegetarians)
eschewed crops which grow below ground.  I don't know if they were
correct, but I just mention this.

--Doug Schwartz
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