They make fresh pressed juices out of vegetables and fruits. No sugar added. It is sort of thin, not slushy like a smoothie is. But it's packed full of micro nutrients. it will most likely be good for your diabetic friends as well.
I am not sure about a no-sugar-added smoothie specifically, but Roxberry has quite a few alternative options and they will substitute ingredients if you ask. You don't need to worry about your diabetic friends. They know how to handle it, and if they decide to have a smoothie they can adjust the amount of insulin they give themselves. Even a smoothie with no added sugar will not be sugar free because there are still carbohydrates in the fruit. Don't worry, your friends can handle themselves.
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