Yes, I can honestly say absolutely a huge difference. I am on day 13 of a 30 day. I’ve done plenty of 5 day fasts, and a number of 8 day fasts. There is a massive difference between day 5 and day 14.
Weight, mental strength, skin clarity just to name a few. Day 10 is where I started to really be able to focus.
I’ve read that fasts beyond 10 days provide diminishing returns as far as metabolic benefits. For example you get higher levels of stem-cell based regeneration after a 10 day compared to a 5 day. However the difference between 10 and 20 day is negligible.