So I’m underweight but doing 3 to 5 days dry fasts to heal my gut. I usually deplete my glycogen stores before fast to enter ketosis quicker. I was thinking, what if I have some carbs(via fruit) to stock up on muscle/liver glycogen that way I won’t burn as much body fat in the first few days but rather I’ll be still running on that stored glucose.
Do you think this would work? Do you think it would make the fast more difficult for too small a benefit ? Do you think I would burn the same amount of fat regardless?
Negligible difference. If you want to pad your fat stores in order to fast more often you will want to consume unsaturated fats to stimulate the torpid/hibernation response in your metabolism. This will prioritize storing food you eat in fat rather than burning it for immediate energy. Adding olive oil and nuts to some of your daily meals should pack on the 3-5kg you want in order to fast 3-5 days weight neutral.