If the goal is to avoid triggering insulin production, and I consume sugar-free sweeteners during the fasting period, does it matter since I can’t produce my own and don’t need to dose for things like that?
According to Gin Stephens of Fast. Feast. Repeat, anything that tastes sweet will trigger your body to expect food and produce insulin, even if you aren’t consuming any calories. She recommends people fast “clean” by consuming nothing but water, electrolytes, black coffee, and black/green/white tea. According to her, even herbal tea with fruit or fruit-flavored waters can throw off a fast for weight loss or to reduce insulin resistance.
Artificial sweeteners also prevent fasting from doing its job of suppressing Ghrenlin, the hunger hormone which means lots of cravings and hard to make it the entire fasting time.
It won’t effect CICO weight loss really, it just won’t give the extra benefits for health and faster weight loss clean fasting does.