Great! That was perfect timing! 40 days would be great. When you are ready to consider adding food, just let me know. We can go over what I'm thinking is worth exploring, but by then you may be so solidly in SS mode you might not be interested! lol! Yes, it would be considered within the keto guidelines. The goal being taking away the stress people often feel of going without regular food, but also only eating mostly fat/moderate protein so as not to stimulate appetite or go to glycogen storage, keeping the insulin levels low. The emotional benefit of having a meal to look forward to every other day, while building good habit of controlled eating, and not disrupting ketosis or raising insulin and stimulating appetite are my thoughts. Whenever you're ready to try it, let me know.