"Janet Wilder" > wrote in message
...
>>
>> I think I will be better off using the rye matzo, not least because now
>> if it works I will have a use for all the halves left over from the
>> Shabbos meals. (The psak I got was to eat the Ashkenazi version of a
>> kezayis, which is half a machine matzo, and consider the other food in
>> the meal to be aggregated with it to get up to the amount needed to be
>> able to wash with a brocho and bentsh afterwards. Sephardim and
>> Lubavitch hold a kezayis is a whole machine matzo.) Another reason is
>> that it doesn't set off further carb cravings.
>
> The word "Kezayis" means like an olive, so the piece should be the size of
> an olive. As far as I know, neither the Ashkenazim nor the Sephardim
> require one to eat anything that would be bad for their health. I think
> this is a shaila for a personal rabbi who understands your medical needs.
>
> Just my opinion.
>
> So paskins rav Janet :-)

Correct, it is not required to eat anything that would be injurious to one's
health.

I have been trying to find a way to still be able to wash for bread, with
the blessing, and say the full grace after meals, on the sabbath, without
losing control of my BG, because it just doesn't feel "shabbosdik" to me to
not do this. I don't care if I don't eat bread during the week.

The halacha is, to make the blessing on the bread and say the full grace
after meals, a kezayis of bread (based on the halachic definition of bread,
which is also different depending what custom one follows, but all have in
common that the dough must include one or more of wheat / rye / spelt / oats
/ barley and be made with water) must be eaten. To additionally say the
blessing on washing the hands prior to blessing and eating the bread, two
kzeisim (= a beitzah) must be eaten.

Kezayis is not defined by what you or I might think based on the grammar.
Most Ashkenazi rabbis posken that a kezayis is the amount equal to the
volume of a fluid ounce. Most Sephardim, as well as Lubavitch, posken that
a kezayis is the weight of an ounce.

I did ask a shaila, and above I explained the answer I got, see the sentence
beginning with "The psak I got was". The answer was further explained as
being based on the Magen Avraham.