"floating in the clouds with joy" describes it so well😊
It's a beautiful feeling.
Maybe it feels so good because when we don't eat we come closer to death. And death is beautiful.
When we are fasting the body doesn't spend energy digesting the food, as such it starts using that energy to heal itself. It starts generating stem cells which are the cells that can transform themselves into any kind cells, commonly seen in pregnancy when the baby is being formed. Then it uses those cells to replace old cells that aren't working properly. There were some experiments where people after fasting had some of their systems regenerated like the dygestive system.
Spiritually speaking it cleanses your mental body, your emotional body and spiritual body, where you get closer to self. You get more tuned with it.
Hence in Buddhism they go for longer periods of fasting to cleanse yada yada all that spiritual jazz.
Some doctors do fasting from time to time but only for the physical advantages of it. It's like a reset to the body.
There were also some cases where fasting cured cancer, don't remember if it was terminal or not. A doctor in the 50's in the US had case studies of that.