Q. Hello Rav,
In an effort to improve my health, I am not supposed to consume sugar. Can I use a sugar free diet soda (like Coke Zero) for kiddush/havdalah? Could I use unsweetened herbal iced tea? Unfortunately, coffee and alcohol both don’t agree with me. Are there other options?
Thank you.

A. Horav Shlomo Miller’s Shlit’a opinion in your shaila is that the options are as follows;
1) Best option, ask someone else to make kiddush or havdala for you.
2) You make kiddush or havdala, but ask someone else who has complied with your recitation to drink.
3) On Shabbos night (Friday) only you may recite kiddush on the challah. You wash netilas yodaim first (along with the others if present), then proceed to recite kiddush and make the hamotzi brocho instead of the usual pri hagofen. At the end you cut the challah, (There are dietetic breads that could be used in need).
4) Dilute the smallest cup of grape juice permitted for kiddush (86 cc) by half with water, and only drink a bit more than half of the cup. The amount of fructose is small.
5) In the day kiddush only you may indeed use herbal iced tea in need. Diet sodas are not an option.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a