So far I have been losing steadily by maintaining a fairly consistent calorie intake of 1200-1500 calories, but some days I do allow myself up to 2000 (maybe once every ten days?) and lower to 1000 the next. But I am considering zig-zagging.
Chris Powell, the trainer from Extreme Makeover: Weight-loss Edition, has his people do what he calls the "boost and burn". Basically he boosts the metabolism one day with a higher calorie, higher fat food intake day, and then follows it up with a lower calorie, lower fat burn day. Basically zig-zagging. The transformations on that show are incredible. He was also on Dr. Oz talking about it.