Fat Adaption??

Just watched an overeating video, and I was wondering about fat adaption. I’ve been eating too much food for 15 years, and I’ve stopped eating, breakfast, flour and sugar. After four days I can go 20 hours without getting hungry, is that fat adaption or something else? Is that too early to be fat adaption?

Also, so one more quick question, does sugar free coffee creamer break your fast?