it took a long time because i would go off it after awhile. like i'd lose 20 in about 6 weeks, then go off for 6 weeks (but never gained any back), then i'd go back on and lose another 20, then take another break, and so on.
you need to get a food scale! it's so much easier measuring out your food with a scale rather than counting out 16 chips or using measuring cups. food scales are cheap, you can get them at walmart.
it is seriously so easy. you really can eat whatever you want! i would eat candy every day because it's my favorite thing.
oh, and if you follow it correctly you should have a nice big loss the first week (usually at least 5 pounds). it's mostly water weight but it's great motivation.