Caloric variation

Caloric variation is supposed to be a way to lose weight faster and more consistently, but it doesn't seem to work for me. I've had two weeks so far where I noticed my calorie count bounced around a lot - 1400, 1700, maybe a day or two breaking 2000 and one down at 1200-1300. And on both those weeks my weight dawdled around, going a little this way, a little that way, averaging out to very little loss for the week. On the other hand, when for several days in a row all my calorie counts are within 100-200 calories, I usually see a good loss that week, and if I gain for a couple of days, a dramatic loss is almost sure to follow.