This article is from the Running FAQ, by Ozzie Gontang with numerous contributions by others.
(Timothy Law Snyder firstname.lastname@example.org)
Oops, here is what makes virutually every person with diabetes bristle:
MYTHS of diabetes!
Not to flame Jay, but diabetics can (and do) eat as much sugar, drink as
much booze, and run as many marathons as anybody else. The challenge is
that they must manage the delicate balance between insulin (which lowers
blood sugar), food (which raises it), and exercise (which, because it
stokes up the metabolism and makes the insulin "rage") lowers blood sugar.
Timing is important, and sometimes, due to the millions of factors that are
at play (and _not_ due to negligence), the blood sugar will go too high or
Before a run, a person with diabetes (nobody in the know calls them
"diabetics" any more) must make sure that the blood sugar is somewhat
higher than normal. This gives a "pad" so that exercise does not result in
a low-sugar crisis. Often the runner will take less insulin the day of the
run. Before (and for long runs, during) the run some food must be eaten.
For short runs, carbos will do, but proteins and fats are also necessary
for the longer hauls.
For a marathon, one must take some sort of food during the run. A high-
carbo source like a soda works well, for the sugar is taken up immediately
and, since the beverage is concentrated, it is easily digested (relative
to, say, the caloric equivalent in whole wheat : ).
Sugar does absolutely _no_ harm to the person with diabetes (provided, they
do not ignore insulin requirements). That's right: The person could knock
off twelve sodas, an entire chocolate cake, and a bag of M&Ms, and be as
"fine" as anybody else (quotes intended---yuk!).
While I am at it, here are a couple of other myth corrections: There is no
clear evidence that diabetes is hereditary. Diabetes has _nothing_ to do
with how much sugar the person ate before acquiring the condition. People
with diabetes can (and do) drink as much alcohol as anybody else. (Alcohol
lowers the blood sugar a tiny bit, so one must be careful to not forget to
eat [and too many cocktails tend to...].)
Hope this helps. Oh, by the way, NO, the taste of something sweet does not
cause the release of insulin (save a possible [and rare] placebo effect).