Is Bulletproof coffee okay to have during Glow15 fasting hours?

While fat is the most metabolically neutral macronutrient (as in it does not produce an insulin response, as does both protein and carbs), it is still optimal to fast completely for the purposes of autophagy on the Glow15 plan. During fasting hours, stick with pure water and water-based beverages, such as black coffee and AutophaTea™ without the added oil.