High Protein Diet Cycle Idea

I was hoping for some comments on this from either people who have tried this or just have ideas on it. When on a diet with a calorie deficit of 1000 calories a day, how detrimental would it be if, say every 4th day of the diet you dropped your food intake to nothing but 800-1000 calories of close to, or nothing but various proteins? (Casein, Whey, Egg, etc) So you would take in say 2200 calories of carbs, pro, and fat for 3 days and then the next day (non-training day) you took in 900 calories with 800 calories of that coming from protein? From what I’ve read, 150g of protein will provide enough resources for the body to spare nitrogen and therefore spare muscle to a fairly decent degree. I can’t see this causing a lowered metabolic rate if done for one day with higher calories being consumed the next day, but maybe I’m wrong. I also can’t see it being too dangerous if done occasionally, as long as it doesn’t get done excessively. I would also think taking in about 30g of carbs or so, and perhaps 2 tsp of flax oil, would also help spare nitrogen and improve fat burning. Also included would be a couple multivitamin/minerals, antioxidants, and other supplements. From reading literature about the protein sparing modified fasts, this seems fairly safe and effective to me, any comments would be appreciated.