Hw many days shud i fast 2 get noticeably thin?

hey guys i recently started fasting.actually im generally a thin guy,but i still hav a small problem.my body is perfectly slim til my stomach but below my stomach,its kinda fat,specially my thighs and my butt.i want tht 2 reduce well enuf coz it sucks and dsnt suit me.actually im fastng these days and i drink water and just hav a small cup of ice cream or just a sandwich each day,nthng more.so guys,how many days do u thnk, will approximately take 4 me 2 see a noticeable change(reduction)of fat on my body specially on my thighs and buttocks.plus i want my chest and calf muscles 2also decrease.actually my chest and calf muscles are naturally well shaped,but i dnt require it coz i wanna b more slim.so is this type of fasting enuf? or shud i use sum othr method 2 reduce fats on these parts quickly?pls dnt suggest me any exercises,just tel me any gud eating habits tht vl hlp.pls nthng related 2 exercises.