Demi, this morning I read your comment about 40 calorie collagen, and then listened to the new DietDoctor podcast on IF, episode #81. The first interview is with Dr. Kevin Gendreax, who said the the most common question he gets is "what can I have on a fast"...his answer ...limit to 35 calories. Dr. Scher's intro to the question is that we really don't know...stick with that and enjoy your collagen.