Fasting Aids and Sweeteners

Bulletproof coffee and bone broth technically break a strict fast because they contain calories. Combining carbohydrates and fat after a fast is treated as a reasonable theoretical concern but overstated in practice. Natural non-caloric sweeteners may cause a cephalic insulin response, but the article says the response is probably small for most people. Habitual bulletproof coffee can add enough calories to eliminate a deficit and stall progress. Artificial sweeteners such as aspartame, sucralose, and saccharin are presented as harmful and to be avoided entirely. The article recommends a blood glucose self-test to assess personal response to sweeteners. Bulletproof coffee or bone broth can be useful if they help extend a fast instead of breaking it early and eating poorly.