I've gone 8 days without eating, on purpose. It was an amazing experience....I had so much more free time, I could smell things like never before, I lost 11 pounds in those 8 days. I totally want to do it again....it's just really really hard to do if you have a very physically or mentally taxing job. I was able to do it during a buyout at a previous company I worked for. I had nothing to do....so no need to think super clearly.
Be careful about your blood pressure when fasting that long....standing up too fast could be very bad for you. Forget exercise. Watch your electrolytes. And be mindful of re-feeding syndrome. It could be deadly. When breaking a prolonged fast, you better know how to do it the right way.
I really want to do it again and I'm sure you'll want to know how it goes when I finally get to do it. And I could use the encouragement to actually go through with it...
There are no new benefits. But you continue to have the "max" benefits from that point in time.