You may want to read up on ghrelin, a hormone that is a factor in appetite. Long story short, after 2 days of fasting it gets easier because your ghrelin levels go down. Then again nothing in biology and certainly hormonal functions is simple, go on and read on.
Once a month I like doing a weekend fast starting Friday , Saturday And breaking fast Sunday @6 .. Going consecutive days (from personal exp) my body just accepts it by Saturday and by Sunday around 4 im pretty weak and cranky. ( I fast w/o liquids ) idk if that helps you gain perspective.. 馃槄馃挄